Aviation Safety
Advancements Being Pursued to Improve Airliner Cabin Occupant Safety and Health
Gao ID: GAO-04-33 October 3, 2003
Airline travel is one of the safest modes of public transportation in the United States. Furthermore, there are survivors in the majority of airliner crashes, according to the National Transportation Safety Board (NTSB). Additionally, more passengers might have survived if they had been better protected from the impact of the crash, smoke, or fire or better able to evacuate the airliner. As requested, GAO addressed (1) the regulatory actions that the Federal Aviation Administration (FAA) has taken and the technological and operational improvements, called advancements, that are available or are being developed to address common safety and health issues in large commercial airliner cabins and (2) the barriers, if any, that the United States faces in implementing such advancements.
FAA has taken a number of regulatory actions over the past several decades to address safety and health issues faced by passengers and flight attendants in large commercial airliner cabins. GAO identified 18 completed actions, including those that require safer seats, cushions with better fire-blocking properties, better floor emergency lighting, and emergency medical kits. GAO also identified 28 advancements that show potential to further improve cabin safety and health. These advancements vary in their readiness for deployment. Fourteen are mature, currently available, and used in some airliners. Among these are inflatable lap seat belts, exit doors over the wings that swing out on hinges instead of requiring manual removal, and photoluminescent floor lighting. The other 14 advancements are in various stages of research, engineering, and development in the United States, Canada, or Europe. Several factors have slowed the implementation of airliner cabin safety and health advancements. For example, when advancements are ready for commercial use, factors that may hinder their implementation include the time it takes for (1) FAA to complete the rule-making process, (2) U.S. and foreign aviation authorities to resolve differences between their respective requirements, and (3) the airlines to adopt or install advancements after FAA has approved their use. When advancements are not ready for commercial use because they require further research, FAA's processes for setting research priorities and selecting research projects may not ensure that the limited federal funding for cabin safety and health research is allocated to the most critical and cost-effective projects. In particular, FAA does not obtain autopsy and survivor information from NTSB after it investigates a crash. This information could help FAA identify and target research to the primary causes of death and injury. In addition, FAA does not typically perform detailed analyses of the costs and effectiveness of potential cabin occupant safety and health advancements, which could help it identify and target research to the most cost-effective projects.
Recommendations
Our recommendations from this work are listed below with a Contact for more information. Status will change from "In process" to "Open," "Closed - implemented," or "Closed - not implemented" based on our follow up work.
Director:
Team:
Phone:
GAO-04-33, Aviation Safety: Advancements Being Pursued to Improve Airliner Cabin Occupant Safety and Health
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Report to the Ranking Democratic Member, Committee on Transportation
and Infrastructure, House of Representatives:
October 2003:
AVIATION SAFETY:
Advancements Being Pursued to Improve Airliner Cabin Occupant Safety
and Health:
GAO-04-33:
GAO Highlights:
Highlights of GAO-04-33, a report to the Ranking Democratic Member,
Committee on Transportation and Infrastructure, House of
Representatives
Why GAO Did This Study:
Airline travel is one of the safest modes of public transportation in
the United States. Furthermore, there are survivors in the majority of
airliner crashes, according to the National Transportation Safety
Board (NTSB). Additionally, more passengers might have survived if
they had been better protected from the impact of the crash, smoke, or
fire or better able to evacuate the airliner. As requested, GAO
addressed (1) the regulatory actions that the Federal Aviation
Administration (FAA) has taken and the technological and operational
improvements, called advancements, that are available or are being
developed to address common safety and health issues in large
commercial airliner cabins and (2) the barriers, if any, that the
United States faces in implementing such advancements.
What GAO Found:
FAA has taken a number of regulatory actions over the past several
decades to address safety and health issues faced by passengers and
flight attendants in large commercial airliner cabins. GAO identified
18 completed actions, including those that require safer seats,
cushions with better fire-blocking properties, better floor emergency
lighting, and emergency medical kits. GAO also identified 28
advancements that show potential to further improve cabin safety and
health. These advancements vary in their readiness for deployment.
Fourteen are mature, currently available, and used in some airliners.
Among these are inflatable lap seat belts, exit doors over the wings
that swing out on hinges instead of requiring manual removal, and
photo-luminescent floor lighting. The other 14 advancements are in
various stages of research, engineering, and development in the United
States, Canada, or Europe.
Several factors have slowed the implementation of airliner cabin
safety and health advancements. For example, when advancements are
ready for commercial use, factors that may hinder their implementation
include the time it takes for (1) FAA to complete the rule-making
process, (2) U.S. and foreign aviation authorities to resolve
differences between their respective requirements, and (3) the
airlines to adopt or install advancements after FAA has approved their
use. When advancements are not ready for commercial use because they
require further research, FAA‘s processes for setting research
priorities and selecting research projects may not ensure that the
limited federal funding for cabin safety and health research is
allocated to the most critical and cost-effective projects. In
particular, FAA does not obtain autopsy and survivor information from
NTSB after it investigates a crash. This information could help FAA
identify and target research to the primary causes of death and
injury. In addition, FAA does not typically perform detailed analyses
of the costs and effectiveness of potential cabin occupant safety and
health advancements, which could help it identify and target research
to the most cost-effective projects.
What GAO Recommends:
This report contains recommendations to FAA to initiate discussions
with NTSB to facilitate the exchange of medical information from
accident investigations and to improve the cost and effectiveness data
available for setting priorities for research on cabin occupant safety
and health. FAA generally agreed with the report‘s contents and its
recommendations.
www.gao.gov/cgi-bin/getrpt?GAO-04-33.
To view the full product, including the scope and methodology, click
on the link above. For more information, contact Gerald Dillingham at
(202) 512-2834 or dillinghamg@gao.gov.
[End of section]
Contents:
Letter:
Results in Brief:
Background:
Regulatory Actions Have Been Taken and Additional Advancements Are
Under Way to Improve Cabin Occupants' Safety and Health:
Several Factors Have Slowed the Implementation of Cabin Occupant Safety
and Health Advancements:
Conclusions:
Recommendations for Executive Action:
Agency Comments and Our Evaluation:
Appendixes:
Appendix I: Objectives, Scope, and Methodology:
Appendix II: Canada and Europe Cabin Occupant Safety and Health
Responsibilities:
Canada:
Europe:
Appendix III: Summary of Key Actions FAA Has Taken to Improve Airliner
Cabin Safety and Health Since 1984:
Appendix IV: Summaries of Potential Impact Safety Advancements:
Retrofitting All Commercial Aircraft with More Advanced Seats:
Improving the Ability of Airplane Floors to Hold Seats in an Accident:
Preventing Overhead Storage Bin Detachment to Protect Passengers in an
Accident:
Child Safety Seats:
Inflatable Lap Belt Air Bags:
Appendix V: Summaries of Potential Fire Safety Advancements:
Fuel Tank Inerting:
Arc Fault Circuit Breaker:
Multisensor Detectors:
Water Mist Fire Suppression:
Fire-Safe Fuels:
Thermal Acoustic Insulation Materials:
Ultra-Fire-Resistant Polymers:
Airport Rescue and Fire-Fighting Operations:
Appendix VI: Summaries of Potential Improved Evacuation Safety
Advancements:
Passenger Safety Briefings:
Exit Seat Briefing:
Photo-luminescent Floor Track Marking:
Crewmember Safety and Evacuation Training:
Acoustic Attraction Signals:
Smoke Hoods:
Exit Slide Testing:
Overwing Exit Doors:
Next Generation Evacuation Equipment and Procedures:
Personal Flotation Devices:
Appendix VII: Summaries of General Cabin Occupant Safety and Health
Advancements:
Advanced Warnings of Turbulence:
Preparations for In-flight Medical Emergencies:
Reducing Health Risks to Passengers with Certain Medical Conditions:
Improved Awareness of Radiation Exposure:
Occupational Safety and Health Standards for Flight Attendants:
Appendix VIII: Application of a Cost Analysis Methodology to Inflatable
Lap Belts:
Inflatable Lap Belts:
Summary of Results:
Methodology:
Appendix IX: GAO Contacts and Staff Acknowledgments:
GAO Contacts:
Staff Acknowledgments:
Tables:
Table 1: Regulatory Actions Taken by FAA to Improve Cabin Occupant
Safety and Health Since 1984:
Table 2: Advancements with Potential to Improve Cabin Occupant Safety
and Health:
Table 3: Status of 10 Significant FAA Rules Pertaining to Airliner Cabin
Occupants' Safety and Health, Fiscal Year 1995 through September of
Fiscal Year 2003:
Table 4: Costs to Equip an Average-sized Airplane in the U.S. Fleet with
Inflatable Lap Seat Belts, Estimated under Alternative Scenarios (In
2002 discounted dollars):
Table 5: Key Assumptions:
Figures:
Figure 1: Inflatable Lap Belt Air Bag Inflation Sequence:
Figure 2: Manual "Self Help" and "Swing Out" Over-Wing Exits:
Figure 3: Funding for Federal Research on Cabin Occupant Safety and
Health Issues, by Facility, Fiscal Years 2000-2005:
Figure 4: Allocation of Federal Funding for Aircraft Cabin Occupant
Safety and Health Research, Fiscal Year 2003:
Figure 5: Coach Seating and Impact Position in Coach Seating:
Figure 6: Examples of Child Safety Seats:
Figure 7: Water Mist Nozzle and Possible Placement:
Figure 8: Fire Insulation Blankets:
Figure 9: Flammable Cabin Materials and Small-scale Material Test
Device:
Figure 10: Airport Rescue and Fire Training:
Figure 11: Airline Briefing to Passengers on Safety Briefing Cards:
Figure 12: Floor Track Marking Using Photo-luminescent Materials:
Figure 13: Test Installation of Acoustic Signalling Device:
Figure 14: An Example of a Commercially Available Smoke Hood:
Figure 15: Drawing of Possible Emergency Slide Testing of FAA's 747 Test
Aircraft:
Figure 16: Airbus' Planned Double Deck Aircraft:
Abbreviations:
ACRM: Advanced Crew Resource Management:
CAMI: Civil Aerospace Medical Institute:
CRM: Crew Resource Management:
DGAC: Direction Générale de l'Aviation Civile:
DOT: Department of Transportation:
DOT IG: Department of Transportation's Inspector General:
DVT: deep vein thrombosis:
EASA: European Aviation Safety Agency:
FAA: Federal Aviation Administration:
ICAO: International Civil Aviation Organization:
JAA: European Joint Aviation Authorities:
NASA: National Aeronautics and Space Administration:
NIOSH: National Institute of Safety and Health:
NTSB: National Transportation Safety Board:
OSHA: Occupational Health and Safety Administration:
TRL: Technical Readiness Level:
TSO: Technical Standing Order:
Letter October 3, 2003:
The Honorable James L. Oberstar
Ranking Democratic Member
Committee on Transportation and Infrastructure
House of Representatives:
Dear Mr. Oberstar:
Airline travel is one of the safest modes of public transportation in
the United States, in large part because of the Congress's, Federal
Aviation Administration's (FAA), commercial airlines', aircraft
manufacturers', and airports' combined efforts to prevent commercial
airliner accidents. Furthermore, although a few airliner accidents are
catastrophic, there are survivors in a majority of crashes. According
to the National Transportation Safety Board (NTSB), passengers survived
in 19 of the 26 U.S. large commercial airliner accidents that occurred
from 1982 through 2001, and in these 19 accidents, over 76 percent of
the passengers (1,523 of 1,988) survived.[Footnote 1] Additionally,
some of the passengers who died in these accidents might have survived
if they had been better protected from the impact of the crash or from
the effects of smoke and fire and had been better able to evacuate the
airliner. This possibility of survival has led federal safety officials
to focus their efforts not only on preventing airliner accidents, but
also on increasing the chances of surviving them.
Over the past several decades, FAA has been taking regulatory actions
to require the implementation of technological and operational
improvements in cabin occupant safety and health to help increase
passengers' chances of surviving large commercial airliner accidents.
In addition, FAA and the aviation community have been conducting
research on new technological and operational improvements, which we
refer to in this report as advancements, whose implementation could
further increase passengers' chances of survival and improve the safety
and health of passengers and flight attendants. This report discusses
regulatory actions that FAA has taken as well as potential advancements
in cabin occupant safety and health that are (1) currently available
but not yet implemented or installed, and (2) not yet available and
subject to additional research to advance the technology or lower
costs. For implementation of these advancements to occur, FAA often has
to take regulatory action, that is, issuing regulations or
airworthiness directives that require the implementation of
technological and operational improvements in cabin occupant safety and
health. FAA continues to pursue regulatory initiatives as well as
conduct research to improve cabin occupant safety and health. The
aviation community is also attempting to enhance the safety and health
of those traveling and working in airliner cabins through such measures
as providing earlier warnings of turbulence and information on the
potential to develop blood clots on long-distance flights. Besides
increasing cabin occupants' safety and health, these actions and
efforts could benefit the airlines by helping to restore passengers'
confidence in the safety of flight and thereby increasing the demand
for air travel, which fell sharply after September 11, 2001, and still
remains below fiscal year 2000 levels.
In response to your request, this report addresses the following
questions: (1) What regulatory actions has FAA taken, and what key
advancements are available or being developed by FAA and others to
address safety and health issues faced by passengers and flight
attendants in large commercial airliner cabins? (2) What factors, if
any, slow the implementation of advancements in cabin occupant safety
and health? In addition, as requested, we identified some factors faced
by Canada and Europe in their efforts to improve cabin occupant safety
and health (see app. II).
To identify the regulatory actions FAA has taken and the key
advancements that are available or being developed to address safety
and health issues facing passengers and flight attendants (cabin
occupants), we reviewed the relevant literature, interviewed FAA
officials, and reviewed FAA's documentation on the regulatory actions
it has taken to enhance cabin occupant safety and health. As part of
this effort, FAA officials identified key regulatory actions that had
been completed in this area. In addition, we interviewed other aviation
safety experts in government, industry, and academia from the United
States, Canada, and Europe. (See app. I for additional information.)
Through our reviews and interviews, we found that FAA's regulatory
actions and advancements fell into four broad categories--three related
to safety in the event of a crash and one related to general cabin
occupant safety and health. The regulatory actions and advancements
related to safety in the event of a crash are those actions taken to
(1) minimize injuries from the impact of a crash, (2) prevent fire or
mitigate its effects, and (3) improve the chances and speed of
evacuation. In addition, we discuss the regulatory actions and
advancements FAA has taken to address a fourth category--improving the
safety and health of cabin occupants. Using the results of our reviews
and interviews, we identified and categorized 28 advancements that are
currently available or being developed, including 5 impact
advancements, 8 fire advancements, 10 evacuation advancements, and 5
cabin occupant safety and health advancements. For each of these
advancements, we discuss the background, research, and regulatory
status.[Footnote 2] We also discuss each advancement's technological
readiness for use in the existing commercial airliner fleet or in newly
produced commercial airplanes. To identify factors that have slowed
implementation of airliner cabin occupant safety and health
advancements, we interviewed FAA, NTSB, and industry officials. In
addition, we analyzed documentation from FAA, NTSB, and aviation safety
experts to identify factors relating to key issues within FAA and the
aviation community related to prioritizing and funding research,
choosing advancements for regulatory implementation, and gaining the
aviation community's acceptance of these advancements.
This report does not address cabin air quality because we are doing
work in this area for another congressional requester. In addition,
given the large scope of this review, the report does not focus on
safety and health issues for flight deck crews (pilots and flight
engineers) since they face some unique issues not faced by cabin
occupants. It also does not address aviation security issues, such as
hijackings, sabotage, or terrorist activities.
We conducted our review from January 2002 through September 2003 in
accordance with generally accepted government auditing standards.
Results in Brief:
FAA has taken a number of key regulatory actions over the past several
decades to improve the safety and health of passengers and flight
attendants in large commercial airliner cabins. We identified 18 such
completed regulatory actions that FAA has taken since 1984. Table 1
shows the number of such actions by category and provides an example
for each category of action.
Table 1: Regulatory Actions Taken by FAA to Improve Cabin Occupant
Safety and Health Since 1984:
Category of regulatory action: Minimize injuries from the impact of a
crash; Example: Stronger seats; Number of key actions taken: 2.
Category of regulatory action: Prevent fire or mitigate its effects;
Example: Fire-blocking seat cushions; Number of key actions taken: 7.
Category of regulatory action: Improve the chances and speed of
evacuation; Example: Emergency floor lighting; Number of key actions
taken: 6.
Category of regulatory action: Improve the safety and health of cabin
occupants; Example: Onboard emergency medical kits; Number of key
actions taken: 3.
Source: GAO.
[End of table]
We also identified 28 advancements that have the potential to increase
the chances of surviving a commercial airliner crash and to improve the
safety and health of cabin occupants--both passengers and flight
attendants. Table 2 shows the number of such advancements by category
and provides an example for each.
Table 2: Advancements with Potential to Improve Cabin Occupant Safety
and Health:
Category of advancement: Minimize injuries from the impact of a crash;
Example: Lap seat belts with inflatable air bags; Number of key
advancements: 5.
Category of advancement: Prevent fire or mitigate its effects; Example:
Reduced fuel tank flammability; Number of key advancements: 8.
Category of advancement: Improve the chances and speed of evacuation;
Example: Improved passenger safety briefings; Number of key
advancements: 10.
Category of advancement: Improve the safety and health of cabin
occupants; Example: Advanced warnings of turbulence; Number of key
advancements: 5.
Source: GAO.
[End of table]
These 28 advancements vary in their readiness for deployment. For
example, 14 of the technologies are currently available but not yet
implemented or installed. Two of these, preparation for in-flight
medical emergencies and improved insulation, were addressed through
separate regulations. These regulations require airlines to install
additional emergency medical equipment (automatic external
defibrillators and enhanced emergency medical kits) by 2004, replace
flammable insulation (metalized Mylar®) with improved insulation by
2005, and manufacture new large commercial airliners with improved
(thermal acoustic) insulation beginning September 2, 2005. Another
currently available advancement is in FAA's rule-making process--
retrofitting the entire existing fleet with significantly stronger
seats. These seats, commonly referred to as 16g seats, for example, can
withstand the force of an impact 16 times a passenger's body weight
(16g), rather than 9 times (9g), as currently required primarily for
new generation commercial aircraft.[Footnote 3] For the remaining 11
currently available advancements, while FAA does not require their use,
some are being used by selected airlines. For example, some airlines
have elected to use inflatable lap seat belts, exit doors over the
wings that swing out on hinges instead of requiring manual removal, and
photo-luminescent floor lighting.[Footnote 4] In addition, some of
these advancements are available for purchase by the flying public,
including smoke hoods and child safety seats certified for use on
commercial airliners. The remaining 14 advancements are in various
stages of research, engineering, and development in the United States,
Canada, or Europe.
Several factors slow the implementation of advancements in cabin
occupant safety and health, including those that are currently
available, but have not yet been implemented or installed and those
that require further research to demonstrate their effectiveness or
lower their costs before they are ready for implementation. For those
that are ready, and for which design and certification standards have
been developed, FAA may undertake the rule-making process to require
their implementation. As our prior work has shown, this process can
take years. In addition, FAA and its international counterparts attempt
to reach agreement on, or harmonize, their requirements for aviation
procedures and equipment. The authorities' current harmonization
process has resulted in a backlog, which has slowed the implementation
of several cabin occupant safety and health advancements. Finally, the
airlines must implement the advancements. While some advancements, such
as improved safety briefings, can be implemented quickly and
economically, others, such as retrofitting commercial aircraft with
stronger passenger seats, require time-consuming, costly changes. FAA
may give the airlines several years to retrofit their fleets in order
to coordinate the change, when possible, with existing maintenance
schedules and allow the airlines to absorb the associated costs. For
advancements that require further research before they can be
considered for use, FAA's multistep process for identifying potential
cabin occupant safety and health research projects and allocating its
limited resources to research projects on the advancements is hampered
by a lack of autopsy and survivor information and cost and
effectiveness data. According to FAA researchers, they have not had
adequate access to autopsy reports and certain survivor information
that NTSB obtains from autopsy reports and interviews with survivors
during its investigations of commercial airliner accidents. This
information could help FAA to identify the principal causes of death
and injury and the major factors affecting survival, and to target
research to advancements addressing these critical causes and factors.
NTSB told us that while they provide large amounts of information on
the causes of death and injury in information they make publicly
available, they would consider making this additional information
available to FAA if steps were taken to safeguard the privacy of
victims and survivors. FAA's multistep process for selecting research
projects on advancements includes consideration of such factors as
their potential impact on accident prevention and accident mitigation;
however, it does not include developing comparable estimates of cost
and effectiveness for competing advancements to allow direct
comparisons between them on their potential to reduce injuries and
deaths. We developed a cost analysis methodology to illustrate how FAA
could develop comparable cost estimates, to enhance its current
process. The results of such analyses could be combined with similar
estimates of effectiveness using data available from a variety of
sources, including industry and academia. Using comparable cost and
effectiveness data across the range of advancements could position the
agency to choose more effectively between competing advancements,
taking into account estimates of the number of injuries and fatalities
that each advancement might prevent for the dollars invested. Such cost
and effectiveness data would provide a valuable supplement to FAA's
current process for setting research priorities and selecting projects
for funding.
This report contains a recommendation to the Secretary of
Transportation to direct the FAA Administrator to initiate discussions
with NTSB to facilitate the exchange of medical information from
accident investigations. In addition, the report contains a
recommendation to the FAA Administrator to improve the analyses
available to decision makers responsible for setting research
priorities and selecting projects for improving the safety and health
of cabin occupants by (1) developing comparable cost estimates of
potential advancements competing for funding and (2) developing or
collecting data on the effectiveness of each potential advancement to
reduce injuries or fatalities. In commenting on a draft of this report,
FAA said that they generally agreed with the report's contents and its
recommendations.
Background:
The safe travel of U.S. airline passengers is a joint responsibility of
FAA and the airlines in accordance with the Federal Aviation Act of
1958, as amended, and the Department of Transportation Act, as amended.
To carry out its responsibilities under these acts, FAA supports
research and development; certifies that new technologies and
procedures are safe; undertakes rule-makings, which when finalized form
the basis of federal aviation regulations; issues other guidance, such
as Advisory Circulars; and oversees the industry's compliance with
standards that aircraft manufacturers and airlines must meet to build
and operate commercial aircraft. Aircraft manufacturers are responsible
for designing aircraft that meet FAA's safety standards, and air
carriers are responsible for operating and maintaining their aircraft
in accordance with the standards for safety and maintenance established
in FAA's regulations. FAA, in turn, certifies aircraft designs and
monitors the industry's compliance with the regulations.
FAA's general process for issuing a regulation, or rule, includes
several steps. When the regulation would require the implementation of
a technology or operation, FAA first certifies that the technology or
operation is safe. Then, FAA publishes a notice of proposed rule-making
in the Federal Register, which sets forth the terms of the rule and
establishes a period for the public to comment on it. Next, FAA reviews
the comments by incorporating changes into the rule that it believes
are warranted, and, in some instances, it repeats these steps one or
more times. Finally, FAA publishes a final rule in the Federal
Register. The final rule includes the date when it will go into effect
and a time line for compliance.
Within FAA, the Aircraft Certification Service is responsible for
certifying that technologies are safe, including improvements to cabin
occupant safety and health, generally through the issuance of new
regulations, a finding certifying an equivalent level of safety, or a
special condition when no rule covers the new technology. The
Certification Service is also responsible for taking enforcement action
to ensure the continued safety of aircraft by prescribing standards for
aircraft manufacturers governing the design, production, and
airworthiness of aeronautical products, such as cabin interiors. The
Flight Standards Service is primarily responsible for certifying an
airline's operations (assessing the airline's ability to carry out its
operations and maintain the airworthiness of the aircraft) and for
monitoring the operations and maintenance of the airline's fleet.
FAA conducts research on cabin occupant safety and health issues in two
research facilities, the Mike Monroney Aeronautical Center/Civil
Aerospace Medical Institute in Oklahoma City, Oklahoma, and the William
J. Hughes Technical Center in Atlantic City, New Jersey. The institute
focuses on the impact of flight operations on human health, while the
technical center focuses on improvements in aircraft design, operation,
and maintenance and inspection to prevent accidents and improve
survivability. For the institute or the technical center to conduct
research on a project, an internal FAA requester must sponsor the
project. For example, FAA's Office of Regulation and Certification
sponsors much of the two facilities' work in support of FAA's rule-
making activities. FAA also cooperates on cabin safety research with
the National Aeronautics and Space Administration (NASA), academic
institutions, and private research organizations.
Until recently, NASA conducted research on airplane crashworthiness at
its Langley Research Center in Hampton, Virginia. However, because of
internal budget reallocations and a decision to devote more of its
funds to aviation security, NASA terminated the Langley Center's
research on the crashworthiness of commercial aircraft in 2002. NASA
continues to conduct fire-related research on cabin safety issues at
its Glenn Research Center in Cleveland, Ohio.
NTSB has the authority to investigate civil aviation accidents and
collects data on the causes of injuries and death for the victims of
commercial airliner accidents. According to NTSB, the majority of
fatalities in commercial airliner accidents are attributable to crash
impact forces and the effects of fire and smoke. Specifically, 306 (66
percent) of the 465 fatalities in partially survivable U.S. aviation
accidents from 1983 through 2000 died from impact forces, 131 (28
percent) died from fire and smoke, and 28 (6 percent) died from other
causes.[Footnote 5]
Surviving an airplane crash depends on a number of factors. The space
surrounding a passenger must remain large enough to prevent the
passenger from being crushed. The force of impact must also be reduced
to levels that the passenger can withstand, either by spreading the
impact over a larger part of the body or by increasing the duration of
the impact through an energy-absorbing seat or fuselage. The passenger
must be restrained in a seat to avoid striking the interior of the
airplane, and the seat must not become detached from the floor. Objects
within the airplane, such as debris, overhead luggage bins, luggage,
and galley equipment, must not strike the passenger. A fire in the
cabin must be prevented, or, if one does start, it must burn slowly
enough and produce low enough levels of toxic gases to allow the
passenger to escape from the airplane. If there is a fire, the
passenger must not have sustained injuries that prevent him or her from
escaping quickly. Finally, if the passenger escapes serious injury from
impact and fire, he or she must have access to exit doors and slides or
other means of evacuation.
Regulatory Actions Have Been Taken and Additional Advancements Are
Under Way to Improve Cabin Occupants' Safety and Health:
Over the past several decades, FAA has taken a number of regulatory
actions designed to improve the safety and health of airline passengers
and flight attendants by (1) minimizing injuries from the impact of a
crash, (2) preventing fire or mitigating its effects, (3) improving the
chances and speed of evacuation, or (4) improving the safety and health
of cabin occupants. (See app. III for more information on the
regulatory actions FAA has taken to improve cabin occupant safety and
health.) Specifically, we identified 18 completed regulatory actions
that FAA has taken since 1984. In addition to these past actions, FAA
and others in the aviation community are pursuing advancements in these
four areas to improve cabin occupant safety and health in the future.
We identified and reviewed 28 such advancements--5 to reduce the impact
of a crash on occupants, 8 to prevent or mitigate fire and its effects,
10 to facilitate evacuation from aircraft, and 5 to address general
cabin occupant safety and health issues.
Minimizing Injuries from the Impact of a Crash:
The primary cause of injury and death for cabin occupants in an
airliner accident is the impact of the crash itself. We identified two
key regulatory actions that FAA has taken to better protect passengers
from impact forces. For example, in 1988, FAA required stronger
passenger seats for newly manufactured commercial airplanes to improve
protection in:
survivable crashes.[Footnote 6] These new seats are capable, for
example, of withstanding an impact force that is approximately 16 times
a passenger's body weight (16g), rather than 9 times (9g), and must be
tested dynamically (in multiple directions to simulate crash
conditions), rather than statically (e.g., drop testing to assess the
damage from the force of the weight alone without motion). In addition,
in 1992, FAA issued a requirement for corrective action (airworthiness
directive) for designs found not to meet the existing rules for
overhead storage bins on certain Boeing aircraft, to improve their
crashworthiness after bin failures were observed in the 1989 crash of
an airliner in Kegworth, England, and a 1991 crash near Stockholm,
Sweden.
We also identified five key advancements that are being pursued to
provide cabin occupants with greater impact protection in the future.
These advancements are either under development or currently available.
Examples include the following:
* Lap seat belts with inflatable air bags: Lap seat belts that contain
inflatable air bags have been developed by private companies and are
currently available to provide passengers with added protection during
a crash. About 1,000 of these lap seat belts have been installed on
commercial airplanes, primarily in the seats facing wall dividers
(bulkheads) to prevent passengers from sustaining head injuries during
a crash. (See fig. 1.):
* Improved seating systems: Seat safety depends on several interrelated
systems operating properly, and, therefore, an airline seat is most
accurately discussed as a system. New seating system designs are being
developed by manufacturers to incorporate new safety and aesthetic
designs as well as meet FAA's 16g seat regulations to better protect
passengers from impact forces. These seating systems would help to
ensure that the seats themselves perform as expected (i.e., they stay
attached to the floor tracks); the space between the seats remains
adequate in a crash; and the equipment in the seating area, such as
phones and video screens, does not increase the impact hazard.
* Child safety seats: Child safety seats could provide small children
with additional protection in the event of an airliner crash. NTSB and
others have recommended their use, and FAA has been involved in this
issue for at least 15 years. While it has used its rule-making process
to consider requiring their use, FAA decided not to require child
safety restraints because its analysis found that if passengers were
required to pay full fare for children under the age of 2, some parents
would choose to travel by automobile and, statistically, the chances
would increase that both the children and the adults would be killed.
FAA is continuing to consider a child safety seat requirement.
Figure 1: Inflatable Lap Belt Air Bag Inflation Sequence:
[See PDF for image]
[End of figure]
Appendix IV contains additional information on the impact advancements
we have identified.
Preventing Fire or Mitigating Its Effect:
Fire prevention and mitigation efforts have given passengers additional
time to evacuate an airliner following a crash or cabin fire. FAA has
taken seven key regulatory actions to improve fire detection, eliminate
potential fire hazards, prevent the spread of fires, and better
extinguish them. For example, to help prevent the spread of fire and
give passengers more time to escape, FAA upgraded fire safety standards
to require that seat cushions have fire-blocking layers, which resulted
in airlines retrofitting 650,000 seats over a 3-year period. The agency
also set new low heat/smoke standards for materials used for large
interior surfaces (e.g., sidewalls, ceilings, and overhead bins), which
FAA officials told us resulted in a significant improvement in
postcrash fire survivability. FAA also required smoke detectors to be
placed in lavatories and automatic fire extinguishers in lavatory waste
receptacles in 1986 and 1987, respectively. In addition, the agency
required airlines to retrofit their fleets with fire detection and
suppression systems in cargo compartments, which according to FAA,
applied to over 3,700 aircraft at a cost to airlines of $300 million.
To better extinguish fires when they do start, FAA also required, in
1985, that commercial airliners carry two Halon fire extinguishers in
addition to other required extinguishers because of Halon's superior
fire suppression capabilities.
We also identified 8 key advancements that are currently available and
awaiting implementation or are under development to provide additional
fire protection for cabin occupants in the future. Examples include the
following:
* Reduced flammability of insulation materials: To eliminate a
potential fire hazard, in May 2000, FAA required that air carriers
replace insulation blankets covered with a type of insulation known as
metalized Mylar® on specific aircraft by 2005, after it was found that
the material had ignited and contributed to the crash of Swiss Air
Flight 111.[Footnote 7] Over 700 aircraft were affected by this
requirement. In addition, FAA issued a rule in July 2003 requiring that
large commercial airplanes manufactured after September 2, 2005, be
equipped with thermal acoustic insulation designed to an upgraded fire
test standard that will reduce the incidence and intensity of in-flight
fires. In addition, after September 2, 2007, newly manufactured
aircraft must be equipped with thermal acoustic materials designed to
meet a new standard for burn-through resistance, providing passengers
more time to escape during a postcrash fire.
* Reduced fuel tank flammability: Flammable vapors in aircraft fuel
tanks can ignite. However, currently available technology can greatly
reduce this hazard by "blanketing" the fuel tank with nonexplosive
nitrogen-enriched air to suppress ("inert") the potential for explosion
of the tank. The U.S. military has used this technology on selected
aircraft for 20 years, but U.S. commercial airlines have not adopted
the technology because of its cost and weight. FAA officials told us
that the military's technology was also unreliable and designed to meet
military rather than civilian airplane design requirements. FAA fire
safety experts have developed a lighter-weight inerting system for
center fuel tanks, which is simpler than the military system and
potentially more reliable. Reliability of this technology is a major
concern for the aviation industry. According to FAA officials, Boeing
and Airbus began flight testing this technology in July 2003 and August
2003, respectively.[Footnote 8] In addition, the Air Transport
Association (ATA) noted that inerting is only one prospective component
of an ongoing major program for fuel tank safety, and that it has yet
to be justified as feasible and cost-effective.
* Sensor technology: Sensors are currently being developed to better
detect overheated or burning materials. According to FAA and the
National Institute of Standards and Technology, many current smoke and
fire detectors are not reliable. For example, a recent FAA study
reported at least one false alarm per week in cargo compartment fire
detection systems. The new detectors are being developed by Airbus and
others in private industry to reduce the number of false alarms. In
addition, FAA is developing standards that would be used to approve
new, reduced false alarm sensors. NASA is also developing new sensors
and detectors.
* Water mist for extinguishing fires: Technology has been under
development for over two decades to dispense water mist during a fire
to protect passengers from heat and smoke and prevent the spread of
fire in the cabin. The most significant development effort has been
made by a European public-private consortium, FIREDETEX, with over 5
million euros of European Community funding and a total project cost of
over 10 million euros (over 10 million U.S. dollars). The development
of this system was prompted, in part, by the need to replace Halon,
when it was determined that this main firefighting agent used in fire
extinguishers aboard commercial airliners depletes ozone in the
atmosphere.
Appendix V contains additional information on advancements that address
fire prevention and mitigation.
Improving the Chances and Speed of Evacuation:
Enabling passengers to evacuate more quickly during an emergency has
saved lives. Over the past two decades, FAA has completed regulatory
action on the following six key requirements to help speed evacuations:
* Improve access to certain emergency exits, such as those generally
smaller exits above the wing, by providing an unobstructed passageway
to the exit.
* Install public address systems that are independently powered and can
be used for at least 10 minutes.
* Help to ensure that passengers in the seats next to emergency exits
are physically and mentally able to operate the exit doors and assist
other passengers in emergency evacuations.
* Limit the distance between emergency exits to 60 feet.
* Install emergency lighting systems that visually identify the
emergency escape path and each exit.
* Install fire-resistant emergency evacuation slides.
We also identified 10 advancements that are either currently available
but awaiting implementation or require additional research that could
lead to improved aircraft evacuation, including the following:
* Improved passenger safety briefings: Information is available to the
airlines on how to develop more appealing safety briefings and safety
briefing cards so that passengers would be more likely to pay attention
to the briefings and be better prepared to evacuate successfully during
an emergency. Research has found that passengers often ignore the oral
briefings and do not familiarize themselves with the safety briefing
cards. FAA has requested that air carriers explore different ways to
present safety information to passengers, but FAA regulates only the
content of briefings. The presentation style of safety briefings is
left up to air carriers.
* Over-wing exit doors: Exit doors located over the wings of some
commercial airliners have been redesigned to "swing out" and away from
the aircraft so that cabin occupants can exit more easily during an
emergency. Currently, the over-wing exit doors on most U.S. commercial
airliners are "self help" doors and must be lifted and stowed by a
passenger, which can impede evacuation. (See fig. 2.) The redesigned
doors are now used on new-generation B-737 aircraft operated by one
U.S. and most European airlines. FAA does not currently require the use
of over-wing exit doors that swing out because the exit doors that are
removed manually meet the agency's safety standards. However, FAA is
working with the Europeans to develop common requirements for the use
of this type of exit door.
* Audio attraction signals: The United Kingdom's Civil Aviation
Authority and the manufacturer are testing audio attraction signals to
determine their usefulness to passengers in locating exit doors during
an evacuation. These signals would be mounted near exits and activated
during an emergency. The signals would help the passengers find the
nearest exit even if lighting and exit signs were obscured by smoke.
Figure 2: Manual "Self Help" and "Swing Out" Over-Wing Exits:
[See PDF for image]
[End of figure]
Appendix VI contains additional information on advancements to improve
aircraft emergency evacuations.
Improving the Safety and Health of Cabin Occupants:
Passengers and flight attendants can face a range of safety and health
effects while aboard commercial airliners. We identified three key
actions taken by FAA to help maintain the safety and health of
passengers and the:
cabin crew during normal flight operations.[Footnote 9] For example, to
prevent passengers from being injured during turbulent conditions, FAA
initiated the Turbulence Happens campaign in 2000 to increase public
awareness of the importance of wearing seatbelts. The agency has
advised the airlines to warn passengers to fasten their seatbelts when
turbulence is expected, and the airlines generally advise or require
passengers to keep their seat belts fastened while seated to help avoid
injuries from unexpected turbulence. FAA has also required the airlines
to equip their fleets with emergency medical kits since 1986. In
addition, Congress banned smoking on most domestic flights in 1990.
We also identified five advancements that are either currently
available but awaiting implementation or require additional research
that could lead to an improvement in the health of passengers and
flight attendants in the future.
* Automatic external defibrillators: Automatic external defibrillators
are currently available for use on some commercial airliners if a
passenger or crew member requires resuscitation. In 1998, the Congress
directed FAA to assess the need for the defibrillators on commercial
airliners. On the basis of its findings, the agency issued a rule
requiring that U.S. airlines equip their aircraft with automatic
external defibrillators by 2004. According to ATA, most airlines have
already done so.
* Enhanced emergency medical kits: In 1998, the Congress directed FAA
to collect data for 1 year on the types of in-flight medical
emergencies that occurred to determine if existing medical kits should
be upgraded. On the basis of the data collected, FAA issued a rule that
required the contents of existing emergency medical kits to be expanded
to deal with a broader range of emergencies. U.S. commercial airliners
are required to carry these enhanced emergency medical kits by 2004.
Most U.S. airlines have already completed this upgrade, according to
ATA.
* Advance warning of turbulence: New airborne weather radar and other
technologies are currently being developed and evaluated to improve the
detection of turbulence and increase the time available to cabin
occupants to avert potential injuries. FAA's July 2003 draft strategic
plan established a performance target of reducing injuries to cabin
occupants caused by turbulence. To achieve this objective, FAA plans to
continue evaluating new airborne weather radars and other technologies
that broadly address weather issues, including turbulence. In addition,
the draft strategic plan set a performance target of reducing serious
injuries caused by turbulence by 33 percent by fiscal year 2008--using
the average for fiscal years 2000 through 2002 of 15 injuries per year
as the baseline and reducing this average to no more than 10 per year.
* Improve awareness of radiation exposure: Flight attendants and
passengers who fly frequently can be exposed to higher levels of
radiation on a cumulative basis than the general public. High levels of
radiation have been linked to an increased risk of cancer and potential
harm to fetuses. To help passengers and crew members estimate their
past and future radiation exposure levels, FAA developed a computer
model, which is publicly available on its Web site [Hyperlink, http://
www.jag.cami.jccbi.gov/cariprofile.asp] http://www.jag.cami.jccbi.gov/
cariprofile.asp. However, the extent to which flight attendants and
frequent flyers are aware of cosmic radiation's risks and make use of
FAA's computer model is unclear. Agency officials told us that they
plan to install a counter capability on its Civil Aerospace Medical
Institute Web site to track the number of visits to its aircrew and
passenger health and safety Web site. FAA also plans to issue an
Advisory Circular by early next year, which incorporates the findings
of a just completed FAA report, "What Aircrews Should Know About Their
Occupational Exposure to Ionizing Radiation." This Advisory Circular
will include recommended actions for aircrews and information on solar
flare event notification of aircrews. In contrast, airlines in Europe
abide by more stringent requirements for helping to ensure that cabin
and flight crew members do not receive excessive doses of radiation
from performing their flight duties during a given year. For example,
in May 1996, the European Union issued a directive for workers,
including air carrier crew members (cabin and flight crews) and the
general public, on basic safety and health protections against dangers
arising from ionizing radiation. This directive set dose limits and
required air carriers to (1) assess and monitor the exposure of all
crew members to avoid exceeding exposure limits, (2) work with those
individuals at risk of high exposure levels to adjust their work or
flight schedules to reduce those levels, and (3) inform crew members of
the health risks that their work involves from exposure to radiation.
It also required airlines to work with female crew members, when they
announce a pregnancy, to avoid exposing the fetus to harmful levels of
radiation. This directive was binding for all European Union member
states and became effective in May 2000.
* Improved awareness of potential health effects related to flying: Air
travel may exacerbate some medical conditions. Of particular concern is
a condition known as Deep Vein Thrombosis (DVT), or travelers'
thrombosis, in which blood clots can develop in the deep veins of the
legs from extended periods of inactivity. In a small percentage of
cases, the clots can break free and travel to the lungs, with
potentially fatal results. Although steps can be taken to avoid or
mitigate some travel-related health effects, no formal awareness
campaigns have been initiated by FAA to help ensure that this
information reaches physicians and the traveling public. The Aerospace
Medical Association's Web site [Hyperlink, http://www.asma.org/
publication.html] http://www.asma.org/publication.html includes
guidance for physicians to use in advising passengers with preexisting
medical conditions on the potential risks of flying, as well as
information for passengers with such conditions to use in assessing
their own potential risks.
See appendix VII for additional information on health-related advances.
Advancements Vary in Their Readiness for Deployment:
The advancements being pursued to improve the safety and health of
cabin occupants vary in their readiness for deployment. For example, of
the 28 advancements we reviewed, 14 are mature and currently available.
Two of these, preparation for in-flight medical emergencies and the use
of new insulation, were addressed through regulations. These
regulations require airlines to install additional emergency medical
equipment (automatic external defibrillators and enhanced emergency
medical kits) by 2004, replace flammable insulation covering (metalized
Mylar®) on specific aircraft by 2005, and manufacture new large
commercial airliners that use a new type of insulation meeting more
stringent flammability test standards after September 2, 2005. Another
advancement is currently in the rule-making process--retrofitting the
existing fleet with stronger 16g seats. The remaining 11 advancements
are available, but are not required by FAA. For example, some airlines
have elected to use inflatable lap seat belts and exit doors over the
wings that swing out instead of requiring manual removal, and others
are using photo-luminescent floor lighting in lieu of or in combination
with traditional electrical lighting. Some of these advancements are
commercially available to the flying public, including smoke hoods and
child safety seats certified for use on commercial airliners. The
remaining 14 advancements are in various stages of research,
engineering, and development in the United States, Canada, or Europe.
Several Factors Have Slowed the Implementation of Cabin Occupant Safety
and Health Advancements:
Several factors have slowed the implementation of airliner cabin
occupant safety and health advancements in the United States. When
advancements are available for commercial use but not yet implemented
or installed, their use may be slowed by the time it takes (1) for FAA
to complete the rule-making process,[Footnote 10] which may be required
for an advancement to be approved for use but may take many years; (2)
for U.S. and foreign aviation authorities to resolve differences
between their respective cabin occupant safety and health requirements;
and (3) for the airlines to adopt or install advancements after FAA has
approved their use, including the time required to schedule an
advancement's installation to coincide with major maintenance cycles
and thereby minimize the costs associated with taking an airplane out
of service. When advancements are not ready for commercial use because
they need further research to develop their technologies or reduce
their costs, their implementation may be slowed by FAA's multistep
process for identifying advancements and allocating its limited
resources to research on potential advancements. FAA's multistep
process is hampered by a lack of autopsy and survivor information from
past accidents and by not having cost and effectiveness data as part of
the decision process. As a result, FAA may not be identifying and
funding the most critical or cost-effective research projects.
FAA's Rule-making Process to Require Advancements Can Be Lengthy:
Once an advancement has been developed, FAA may require its use, but
significant time may be required before the rule-making process is
complete. One factor that contributes to the length of this process is
a requirement for cost-benefit analyses to be completed. Time is
particularly important when safety is at stake or when the pace of
technological development exceeds the pace of rule-making. As a result,
some rules may need to be developed quickly to address safety issues or
to guide the use of new technologies. However, rules must also be
carefully considered before being finalized because they can have a
significant impact on individuals, industries, the economy, and the
environment. External pressures--such as political pressure generated
by highly publicized accidents, recommendations by NTSB, and
congressional mandates--as well as internal pressures, such as changes
in management's emphasis, continue to add to and shift the agency's
priorities.
The rule-making process can be long and complicated and has delayed the
implementation of some technological and operational safety
improvements, as we reported in July 2001.[Footnote 11]In that report,
we reviewed 76 significant rules in FAA's workload for fiscal years
1995 through 2000--10 of the 76 were directly related to improving the
safety and health of cabin occupants.[Footnote 12] Table 3 details the
status or disposition of these 10 rules. The shortest rule-making
action took 1 year, 11 months (for child restraint systems), and the
longest took 10 years, 1 month (for the type and number of emergency
exits). However, one proposed rule was still pending after 15 years,
while three others were terminated or withdrawn after 9 years or more.
Of the 76 significant rules we reviewed, FAA completed the rule-making
process for 29 of them between fiscal year 1995 and fiscal year 2000,
in a median time of about 2 ½ years to proceed from formal initiation
of the rule-making process through publication of the final rule;
however, FAA took 10 years or more to move from formal initiation of
the rule-making process through publication of the final rule for 6 of
these 29 rules.
Table 3: Status of 10 Significant FAA Rules Pertaining to Airliner
Cabin Occupants' Safety and Health, Fiscal Year 1995 through September
of Fiscal Year 2003:
Rule title: Flight attendant requirements; Initiation date[A]: 2/04/86;
Time elapsed: 9 years, 8 months; Status/disposition:
Terminated/withdrawn 6/06/96.
Rule title: Type and number of passenger emergency exits required in
transport category airplanes; Initiation date[A]: 10/15/86; Time
elapsed: 10 years, 1 month; Status/disposition: Final rule
published on 11/08/96.
Rule title: Airworthiness standards; occupant protection standards for
commuter category airplanes; Initiation date[A]: 5/29/87; Time elapsed:
11 years, 1 month; Status/disposition: Terminated/withdrawn;
6/30/98.
Rule title: Retrofit of improved seats in air carrier transport
category airplanes; Initiation date[A]: 1/26/88; Time elapsed: 15
years, 6 months; Status/disposition: Pending.
Rule title: Child restraint systems; Initiation date[A]: 5/30/90; Time
elapsed: 5 years, 9 months; Status/disposition: Terminated/
withdrawn; 2/13/96.
Rule title: Revised access to Type III exits; Initiation date[A]: 10/
30/92; Time elapsed: 9 years, 5 months; Status/disposition:
Withdrawn; 5/03/02.
Rule title: Child restraint systems; Initiation date[A]: 7/18/94; Time
elapsed: 1 year 11 months; Status/disposition: Final rule
published on 6/04/96.
Rule title: Child restraint systems; Initiation date[A]: 4/07/97; Time
elapsed: 6 years, 3 months; Status/disposition: Pending.
Rule title: Emergency medical equipment; Initiation date[A]: 10/5/98;
Time elapsed: 2 years, 8 months; Status/disposition: Final
rule published on; 6/12/01.
Rule title: Improved flammability standards for thermal acoustic
insulation materials in transport category aircraft; Initiation
date[A]: 12/04/98; Time elapsed: 4 years, 7 months; Status/
disposition: Final rule published on July 31, 2003.
Source: GAO analysis of FAA data.
Note: In commenting on a draft of this report, FAA noted that examining
the years elapsed from the initiation date of the rule to disposition
can be unfair to some actions and that many of the delays were not the
fault of FAA.
[A] Initiation dates were identified in FAA's rule-making information
system as GAO reported in July 2001. This was the only source for data
on the agency's internal milestones, including "initiation date.":
[End of table]
Differences in U.S. and Foreign Requirements Can Hamper Adoption of
Advancements:
FAA and its international counterparts, such as the European Joint
Aviation Authorities (JAA), impose a number of requirements to improve
safety. At times, these requirements differ, and efforts are needed to
reach agreement on procedures and equipment across country borders. In
the absence of such agreements, the airlines generally must adopt
measures to implement whichever requirement is more stringent. In 1992,
FAA and JAA began harmonizing their requirements for (1) the design,
manufacture, operation, and maintenance of civil aircraft and related
product parts; (2) noise and emissions from aircraft; and (3) flight
crew licensing. Harmonizing the U.S. Federal Aviation Regulations with
the European Joint Aviation Regulations is viewed by FAA as its most
comprehensive long-term rule-making effort and is considered critical
to ensuring common safety standards and minimizing the economic burden
on the aviation industry that can result from redundant inspection,
evaluation, and testing requirements.
According to both FAA and JAA, the process they have used to date to
harmonize their requirements for commercial aircraft has not
effectively prioritized their joint recommendations for harmonizing
U.S. and European aviation requirements, and led to many
recommendations going unpublished for years. This includes a backlog of
over 130 new rule-making efforts. The slowness of this process led the
United States and Europe to develop a new rule-making process to
prioritize safety initiatives, focus the aviation industry's and their
own limited resources, and establish limitations on rule-making
capabilities. Accordingly, in March 2003, FAA and JAA developed a draft
joint "priority" rule-making list; collected and considered industry
input; and coordinated with FAA's, JAA's, and Transport Canada Civil
Aviation's management. This effort has resulted in a rule-making list
of 26 priority projects. In June 2003, at the 20TH Annual JAA/FAA
International Conference, FAA, JAA, and Transport Canada Civil Aviation
discussed the need to, among other things, support the joint priority
rule-making list and to establish a cycle for updating it--to keep it
current and to provide for "pop-up," or unexpected, rule-making needs.
FAA and JAA discussed the need to prioritize rule-making efforts to
efficiently achieve aviation safety goals; that they would work from a
limited agreed-upon list for future rule-making activities; and that
FAA and the European Aviation Safety Agency, which is gradually
replacing JAA, should continue with this approach.
In the area of cabin occupant safety and heath, some requirements have
been harmonized, while others have not. For example, in 1996, JAA
changed its rule on floor lighting to allow reflective, glow-in-the-
dark material to be used rather than mandating the electrically powered
lighting that FAA required. The agency subsequently permitted the use
of this material for floor lighting. In addition, FAA finalized a rule
in July 2003 to require a new type of insulation designed to delay fire
burning though the fuselage into the cabin during an accident. JAA
favors a performance-based standard that would specify a minimum delay
in burn-through time, but allow the use of different technologies to
achieve the standard. FAA officials said that the agency would consider
other technologies besides insulation to achieve burn-through
protection but that it would be the responsibility of the applicant to
demonstrate that the technology provided performance equivalent to that
stipulated in the insulation rule. JAA officials told us that these are
examples of the types of issues that must be resolved when they work to
harmonize their requirements with FAA's. These officials added that
this process is typically very time consuming and has allowed for
harmonizing about five rules per year.
Significant Time May Be Needed to Implement Advancements Once They Are
Required, but Some May Enhance Airlines' Competitiveness:
After an advancement has been developed, shown to be beneficial,
certified, and required by FAA, the airlines or manufacturers need time
to implement or install the advancement.[Footnote 13] FAA generally
gives the airlines or manufacturers a window of time to comply with its
rules. For example, FAA gave air carriers 5 years to replace metalized
Mylar® insulation on specific aircraft with a less flammable insulation
type, and FAA's proposed rule-making on 16g seats would give the
airlines 14 years to install these seats in all existing commercial
airliners. ATA officials told us that this would require replacement of
496,000 seats.
The airline industry's recent financial hardships may also delay the
adoption of advancements. Recently, two major U.S. carriers filed for
bankruptcy,[Footnote 14] and events such as the war in Iraq have
reduced passenger demand and airline revenues below levels already
diminished by the events of September 11, 2001, and the economic
downturn. Current U.S. demand for air travel remains below fiscal year
2000 levels. As a result, airlines may ask for exemptions from some
requirements or extensions of time to install advancements.
While implementing new safety and health advancements can be costly for
the airlines, making these changes could improve the public's
confidence in the overall safety of air travel. In addition, some
aviation experts in Europe told us that health-related cabin
improvements, particularly improvements in air quality, are of high
interest to Europeans and would likely be used in the near future by
some European air carriers to set themselves apart from their
competitors.
FAA's Multistep Process for Allocating Limited Resources to Research
Projects Is Hampered by Lack of Autopsy and Survivor Information and
Cost and Effectiveness Data:
For fiscal year 2003, FAA and NASA allocated about $16.2 million to
cabin occupant safety and health research. FAA's share of this research
represented $13.1 million, or about 9 percent of the agency's Research,
Engineering, and Development budget of $148 million for fiscal year
2003. Given the level of funding allocated to this research effort, it
is important to ensure that the best research projects are selected.
However, FAA's processes for setting research priorities and selecting
projects for further research are hampered by data limitations. In
particular, FAA lacks certain autopsy and survivor information from
aircraft crashes that could help it identify and target research to the
most important causes of death and injury in an airliner crash. In
addition, for the proposed research projects, the agency does not (1)
develop comparable cost data for potential advancements or (2) assess
their potential effectiveness in minimizing injuries or saving lives.
Such cost and effectiveness data would provide a valuable supplement to
FAA's current process for setting research priorities and selecting
projects for funding.
Federal Research on Aircraft Cabin Occupant Safety and Health Issues:
Both FAA and NASA conduct research on aircraft cabin occupant safety
and health issues. The Civil Aeromedical Institute (CAMI) and the
Hughes Technical Center are FAA's primary facilities for conducting
research in this area. In addition, two facilities at NASA, the Langley
and Glenn research centers, have also conducted research in this area.
As figure 3 shows, federal funding for this research since fiscal year
2000, reached a high in fiscal year 2002, at about $17 million, and
fell to about $16.2 million in fiscal year 2003. The administration's
proposal for fiscal year 2004 calls for a further reduction to $15.9
million. This funding covers the expenses of researchers at these
facilities and of the contracts they may have with others to conduct
research. In addition, NASA recently decided to end its crash research
at Langley and to close a drop test facility that it operates in
Hampton, Virginia.
Figure 3: Funding for Federal Research on Cabin Occupant Safety and
Health Issues, by Facility, Fiscal Years 2000-2005:
[See PDF for image]
Note: FAA Hughes Technical Center data includes work in fire-safe
fuels, fuel-tank inerting, arc fault circuit breakers, and airport
rescue and fire-fighting operations.
[End of figure]
In fiscal year 2003, FAA and NASA both supported research projects,
including aircraft impact, fire, evacuation, and health. As figure 4
shows, most of the funding for cabin occupant safety and health
research has gone to fire-related projects.
Figure 4: Allocation of Federal Funding for Aircraft Cabin Occupant
Safety and Health Research, Fiscal Year 2003:
[See PDF for image]
Note: Sum of bars exceeds $16.2 million due to rounding. FAA Technical
Center data includes work in fire-safe fuels, fuel-tank inerting, arc
fault circuit breakers, and airport rescue and fire-fighting
operations:
[End of figure]
FAA Research Selection Process Hampered by Lack of Autopsy and Survivor
Information and Cost and Effectiveness Analyses:
To establish research priorities and select projects to fund, FAA uses
a multistep process. First, within each budget cycle, a number of
Technical Community Representative Group subcommittees from within FAA
generate research ideas. Various subcommittees have responsibility for
identifying potential safety and health projects, including
subcommittees on crash dynamics, fire safety, structural integrity,
passenger evacuation, aeromedical, and fuel safety. Each subcommittee
proposes research projects to review committees, which prioritize the
projects. The projects are considered and weighted according to the
extent to which they address (1) accident prevention, (2) accident
survival, (3) external requests for research, (4) internal requests for
research, and (5) technology research needs. In addition, the cost of
the proposed research is considered before arriving at a final list of
projects. The prioritized list is then considered by the Program
Planning Team, which reviews the projects from a policy perspective.
Although the primary causes of death and injury in commercial airliner
crashes are known to be impact, fire, and impediments to evacuation,
FAA does not have as detailed an understanding as it would like of the
critical factors affecting survival in a crash. According to FAA
officials, obtaining a more detailed understanding of these factors
would assist them in setting research priorities and in evaluating the
relative importance of competing research proposals. To obtain a more
detailed understanding of the critical factors affecting survival, FAA
believes that it needs additional information from passenger autopsies
and from passengers who survived. With this information, FAA could then
regulate safety more effectively, airplane and equipment designers
could build safer aircraft, including cabin interiors, and more
passengers could survive future accidents as equipment became safer.
While FAA has independent authority to investigate commercial airliner
crashes, NTSB generally controls access to the accident investigation
site in pursuit of its primary mission of determining the cause of the
crash. When NTSB concludes its investigation, it returns the airplane
to its owner and keeps the records of the investigation, including the
autopsy reports and the information from survivors that NTSB obtains
from medical authorities and through interviews or questionnaires. NTSB
makes summary information on the crashes publicly available on its Web
site, but according to the FAA researchers, this information is not
detailed enough for their needs. For example, the researchers would
like to develop a complete autopsy database that would allow them to
look for common trends in accidents, among other things. In addition,
the researchers would like to know where survivors sat on the airplane,
what routes they took to exit, what problems they encountered, and what
injuries they sustained. This information would help the researchers
analyze factors that might have an impact on survival. According to the
NTSB's Chief of the Survival Factors Division in the Office of Aviation
Safety, NTSB provides information on the causes of death and a
description of injuries in the information they make publicly
available. In addition, although medical records and autopsy reports
are not made public, interviews with and questionnaires from survivors
are available from the public docket.
NTSB's Medical Officer was unaware of any formal requests from the FAA
for the NTSB to provide them with copies of this type of information,
although the FAA had previously been invited to review such information
at NTSB headquarters. He added that the Board would likely consider a
formal request from FAA for copies of autopsy reports and certain
survivor records, but that it was also likely that the FAA would have
to assure NTSB that the information would be appropriately safeguarded.
According to FAA officials, close cooperation between the NTSB and the
FAA is needed for continued progress in aviation safety.
Besides lacking detailed information on the causes of death and injury,
FAA does not develop data on the cost to implement advancements that
are comparable for each, nor does it assess the potential effectiveness
of each advancement in reducing injuries and saving lives.
Specifically, FAA does not conduct cost-benefit analyses as part of its
multistep process for setting research priorities. Making cost
estimates of competing advancements would allow direct comparisons
across alternatives, which, when combined with comparable estimates of
effectiveness, would provide valuable supplemental information to
decision makers when setting research priorities. FAA considers its
current process to be appropriate and sufficient. In commenting on a
draft of this report, FAA noted that it is very difficult to develop
realistic cost data for advancements during the earliest stages of
research. The agency cautioned that if too much emphasis is placed on
cost/benefit analyses, potentially valuable research may not be
undertaken. Recognizing that it is less difficult to develop cost and
effectiveness information as research progresses, we are recommending
that FAA develop and use cost and effectiveness analyses to supplement
its current process. At later stages in the development process, we
found that this information can be developed fairly easily through cost
and effectiveness analyses using currently available data. For example,
we performed an analysis of the cost to implement inflatable lap seat
belts using a cost analysis methodology we developed (see app. VIII).
This analysis allowed us to estimate how much this advancement would
cost per airplane and per passenger trip. Such cost analyses could be
combined with similar analyses of effectiveness to identify the most
cost-effective projects, based on their potential to minimize injuries
and reduce fatalities. Potential sources of effectiveness data include
FAA, academia, industry, and other aviation authorities.
Conclusions:
Although FAA and the aviation community are pursuing a number of
advancements to enhance commercial airliners' cabin occupant safety and
health, several factors have slowed their implementation. For example,
for advancements that are currently available but are not yet
implemented or installed, progress is slowed by the length of time it
takes for FAA to complete its rule-making process, for the U.S and
foreign countries to agree on the same requirements, and for the
airlines to actually install the advancements after FAA has required
them. In addition, FAA's multistep process for identifying potential
cabin occupant safety and health research projects and allocating its
limited research funding is hampered by the lack of autopsy and
survivor information from airliner crashes and by the lack of cost and
effectiveness analysis. Given the level of funding allocated to cabin
occupant safety and health research, it is important for FAA to ensure
that this funding is targeting the advancements that address the most
critical needs and show the most promise for improving the safety and
health of cabin occupants. However, because FAA lacks detailed autopsy
and survivor information, it is hampered in its ability to identify the
principal causes of death and survival in commercial airliner crashes.
Without an agreement with the National Transportation Safety Board
(NTSB) to receive detailed autopsy and survivor information, FAA lacks
information that could be helpful in understanding the factors that
contribute to surviving a crash. Furthermore, because FAA does not
develop comparable estimates of cost and effectiveness of competing
research projects, it cannot ensure that it is funding those
technologies with the most promise of saving lives and reducing
injuries. Such cost and effectiveness data would provide a valuable
supplement to FAA's current process for setting research priorities and
selecting projects for funding. To facilitate FAA's development of
comparable cost data across advancements, we developed a cost analysis
methodology that could be combined with a similar analysis of
effectiveness to identify the most cost-effective projects. Using
comparable cost and effectiveness data across the range of advancements
would position the agency to choose more effectively between competing
advancements, taking into account estimates of the number of injuries
and fatalities that each advancement might prevent for the dollars
invested. In turn, FAA would have more assurance that the level of
funding allocated to this effort maximizes the safety and health of the
traveling public and the cabin crew members who serve them.
Recommendations for Executive Action:
To provide FAA decision makers with additional data for use in setting
priorities for research on cabin occupant safety and health and in
selecting competing research projects for funding, we recommend that
the Secretary of Transportation direct the FAA Administrator to:
* initiate discussions with the National Transportation Safety Board in
an effort to obtain the autopsy and survivor information needed to more
fully understand the factors affecting survival in a commercial
airliner crash and:
* supplement its current process by developing and using comparable
estimates of cost and effectiveness for each cabin occupant safety and
health advancement under consideration for research funding.
Agency Comments and Our Evaluation:
We provided copies of a draft of this report to the Department of
Transportation for its review and comment. FAA generally agreed with
the report's contents and its recommendations. The agency provided us
with oral comments, primarily technical clarifications, which we have
incorporated as appropriate.
:
As agreed with your office, unless you publicly announce its contents
earlier, we plan no further distribution of this report until 10 days
after the date of this letter. At that time, we will send copies to the
appropriate congressional committees; the Secretary of Transportation;
the Administrator, FAA; and the Chairman, NTSB. We will also make
copies available to others upon request. In addition, this report is
also available at no charge on GAO's Web site at [Hyperlink, http://
www.gao.gov] http://www.gao.gov.
Contacts and staff acknowledgements for this report are included in
appendix IX. If you or your staff have any questions, please contact me
or Glen Trochelman at (202) 512-2834:
Sincerely yours,
Gerald L. Dillingham
Director, Physical Infrastructure Issues:
Signed by Gerald L. Dillingham:
[End of section]
Appendixes:
[End of section]
Appendix I: Objectives, Scope, and Methodology:
As requested by the Ranking Democratic Member, House Committee on
Transportation and Infrastructure, we addressed the following
questions: (1) What regulatory actions has the Federal Aviation
Administration (FAA) taken, and what key advancements are available or
being developed by FAA and others to address safety and health issues
faced by passengers and flight attendants in large commercial airliner
cabins? (2) What factors, if any, slow the implementation of
advancements in cabin occupant safety and health? In addition, as
requested, we identified some factors affecting efforts by Canada and
Europe to improve cabin occupant safety and health.
The scope of our report includes the cabins of large commercial
aircraft (those that carry 30 or more passengers) operated by U.S.
domestic commercial airlines and addresses the safety and health of
passengers and flight attendants from the time they board the airliner
until they disembark under normal operational conditions or emergency
situations. This report identifies cabin occupant safety and health
advancements (technological or operational improvements) that could be
implemented, primarily through FAA's rule-making process. Such
improvements include technological changes designed to increase the
overall safety of commercial aviation as well as changes to enhance
operational safety. The report does not include information on the
flight decks of large commercial airliners or safety and health issues
affecting flight deck crews (pilots and flight engineers), because they
face some issues not faced by cabin occupants. It also does not address
general aviation and corporate aircraft or aviation security issues,
such as hijackings, sabotage, or terrorist activities.
To identify regulatory actions that FAA has taken to address safety and
health issues faced by passengers and flight attendants in large
commercial airliner cabins, we interviewed and collected documentation
from U.S. federal agency officials on major safety and health efforts
completed by FAA. The information we obtained included key dates and
efforts related to cabin occupant safety and health, such as rule-
makings, airworthiness directives, and Advisory Circulars.
To identify key advancements that are available or are being developed
by FAA and others to address safety and health issues faced by
passengers and flight attendants in large commercial airliner cabins,
we consulted experts (1) to help ensure that we had included the
advancements holding the most promise for improving safety and health;
and (2) to help us structure an evaluation of selected advancements
(i.e., confirm that we had included the critical benefits and drawbacks
of the potential advancements) and develop a descriptive analysis for
them, where appropriate, including their benefits, costs, technology
readiness levels, and regulatory status. In addition, we interviewed
and obtained documentation from federal agency officials and other
aviation safety experts at the Federal Aviation Administration
(including its headquarters in Washington, D.C; Transport Airplane
Directorate in Renton, Washington; William J. Hughes Technical Center
in Atlantic City, New Jersey; and Mike Monroney Aeronautical Center/
Civil Aerospace Medical Institute in Oklahoma City, Oklahoma); National
Transportation Safety Board; National Aeronautics and Space
Administration (NASA); Air Transport Association; Regional Airline
Association; International Air Transport Association; Aerospace
Industries Association; Aerospace Medical Association; Flight Safety
Foundation, Association of Flight Attendants; Boeing Commercial
Airplane Group; Airbus; Cranfield University, United Kingdom;
University of Greenwich, United Kingdom; National Aerospace Laboratory,
Netherlands; Joint Aviation Authorities, Netherlands; Civil Aviation,
Netherlands; Civil Aviation Authority, United Kingdom; RGW Cherry and
Associates; Air Accidents Investigations Branch, United Kingdom;
Syndicat National du Personnel Navigant Commercial (French cabin crew
union) and ITF Cabin Crew Committee, France; BEA (comparable to the
U.S. NTSB), France; and the Direction Générale de l'Aviation Civile
(DGAC), FAA's French counterpart.
To describe the status of key advancements that are available or under
development, we used NASA's technology readiness levels (TRL). These
levels form a system for ranking the maturity of particular
technologies and are as follows:
* TRL 1: Basic principles observed and reported:
* TRL 2: Technology concept and/or application formulated:
* TRL 3: Analytical and experimental critical function and/or
characteristic proof-of-concept developed:
* TRL 4: Component validation in laboratory environment:
* TRL 5: Component and/or validation in relevant environment:
* TRL 6: System or subsystem model or prototype demonstrated in a
relevant environment:
* TRL 7: System prototype demonstrated in a space environment:
* TRL 8: Actual system completed and "flight qualified" through test
and demonstration:
* TRL 9: Actual system "flight proven" through successful mission
operations:
To determine what factors, if any, slow the implementation of
advancements in cabin occupant safety and health, we reviewed the
relevant literature and interviewed and analyzed documentation from the
U.S. federal officials cited above for the 18 key regulatory actions
FAA has taken since 1984 to improve the safety and health of cabin
occupants. We used this same approach to assess the regulatory status
of the 28 advancements we reviewed that are either currently available,
but not yet implemented or installed, or require further research to
demonstrate their effectiveness or lower their costs. In identifying 28
advancements, GAO is not suggesting that these are the only
advancements being pursued; rather, these advancements have been
recognized by aviation safety experts we contacted as offering promise
for improving the safety and health of cabin occupants. To determine
how long it generally takes for FAA to issue new rules, in addition to
speaking with FAA officials, we relied on past GAO work and updated it,
as necessary. In order to examine the effect of FAA and European
efforts to harmonize their aviation safety requirements, we interviewed
and analyzed documentation from aviation safety officials and other
experts in the United States, Canada, and Europe. Furthermore, to
examine the factors affecting airlines' ability to implement or install
advancements after FAA requires them, we interviewed and analyzed
documentation from aircraft manufacturers, ATA, and FAA officials.
In addition, to determine what factors slow implementation we examined
FAA's processes for selecting research projects to improve cabin
occupant safety and health. In examining whether FAA has sufficient
data upon which to base its research priorities, we interviewed FAA and
National Transportation Safety Board (NTSB) officials about autopsy and
survivor information from commercial airliner accidents. We also
examined the use of cost and effectiveness data in FAA's research
selection process for cabin occupant safety and health projects. To
facilitate FAA's development of such cost estimates, we developed a
cost analysis methodology to illustrate how the agency could do this.
Specifically, we developed a cost analysis for inflatable lap belts to
show how data on key cost variables could be obtained from a variety of
sources. We selected lap belts because they were being used in limited
situations and appeared to offer some measure of improved safety.
Information on installation price, annual maintenance and refurbishment
costs, and added weight of these belts was obtained from belt
manufacturers. We obtained information from FAA and the Department of
Transportation's (DOT) Bureau of Transportation Statistics on a number
of cost variables, including historical jet fuel prices, the impact on
jet fuel consumption of carrying additional weight, the average number
of hours flown per year, the average number of seats per airplane, the
number of airplanes in the U.S. fleet, and the number of passenger
tickets issued per year. To account for variation in the values of
these cost variables, we performed a Monte Carlo simulation.[Footnote
15] In this simulation, values were randomly drawn 10,000 times from
probability distributions characterizing possible values for the number
of seat belts per airplane, seat installation price, jet fuel price,
number of passenger tickets, number of airplanes, and hours flown. This
simulation resulted in forecasts of the life-cycle cost per airplane,
the annualized cost per airplane, and the cost per ticket. There is
uncertainty in estimating the number of lives potentially saved and
their value because accidents occur infrequently and unpredictably.
Such estimates could be higher or lower, depending on the number and
severity of accidents during a given analysis period and the value
placed on a human life.
To identify factors affecting efforts by Canada and Europe to improve
cabin occupant safety and health we interviewed and collected
documentation from aviation safety experts in the United States,
Canada, and Europe.
We provided segments of a draft of this report to selected external
experts to help ensure its accuracy and completeness. These included
the Air Transport Association, National Transportation Safety Board,
Boeing, Airbus, and aviation authorities in the United Kingdom, France,
Canada and the European Union. We incorporated their comments, as
appropriate. The European Union did not provide comments.
We conducted our review from January 2002 through September 2003 in
accordance with generally accepted government auditing standards.
[End of section]
Appendix II: Canada and Europe Cabin Occupant Safety and Health
Responsibilities:
The United States, Canada, and members of the European Community are
parties to the International Civil Aviation Organization (ICAO),
established under the Chicago Convention of 1944, which sets minimum
standards and recommended practices for civil aviation. In turn,
individual nations implement aviation standards, including those for
aviation safety. While ICAO's standards and practices are intended to
keep aircraft, crews, and passengers safe, some also address
environmental conditions in aircraft cabins that could affect the
health of passengers and crews. For example, ICAO has standards for
preventing the spread of disease and for spraying aircraft cabins with
pesticides to remove disease-carrying insects.
Canada:
In Canada, FAA's counterpart for aviation regulations and oversight is
Transport Canada Civil Aviation, which sets standards and regulations
for the safe manufacture, operation, and maintenance of aircraft in
Canada. In addition, Transport Canada Civil Aviation administers,
enforces, and promotes the Aviation Occupational Health and Safety
Program to help ensure the safety and health of crewmembers on board
aircraft.[Footnote 16] The department also sets the training and
licensing standards for aviation professionals in Canada, including air
traffic controllers, pilots, and aircraft maintenance engineers.
Transport Canada Civil Aviation has more than 800 inspectors working
with Canadian airline operators, aircraft manufacturers, airport
operators, and air navigation service providers to maintain the safety
of Canada's aviation system. These inspectors monitor, inspect, and
audit Canadian aviation companies to verify their compliance with
Transport Canada's aviation regulations and standards for pilot
licensing, aircraft certification, and aircraft operation.
To assess and recommend potential changes to Canada's aviation
regulations and standards, the Canadian Aviation Regulation Advisory
Council was established. This Council is a joint initiative between
government and the aviation community. The Council supports regulatory
meetings and technical working groups, which members of the aviation
community can attend. A number of nongovernmental organizations--
including airline operators, aviation labor organizations,
manufacturers, industry associations, and groups representing the
public--are members.
The Transportation Safety Board (TSB) of Canada is similar to NTSB in
the United States. TSB is a federal agency that operates independently
of Transport Canada Civil Aviation. Its mandate is to advance safety in
the areas of marine, pipeline, rail, and aviation transportation by:
* conducting independent investigations, including public inquiries
when necessary, into selected transportation occurrences in order to
make findings as to their causes and contributing factors;
* identifying safety deficiencies, as evidenced by transportation
occurrences;
* making recommendations designed to reduce or eliminate any such
deficiencies; and:
* reporting publicly on their investigations and findings.
Under its mandate to conduct investigations, TSB conducts safety-issue-
related investigations and studies. It also maintains a mandatory
incident-reporting system for all modes of transportation. TSB and
Transport Canada Civil Aviation use the statistics derived from this
information to track potential safety concerns in Canada's
transportation system.
TSB investigates aircraft accidents that occur in Canada or involve
aircraft built there. Like NTSB, the Transportation Safety Board can
recommend air safety improvements to Transport Canada Civil Aviation.
Europe:
Europe supplements the ICAO framework with the European Civil Aviation
Conference, an informal forum through which 38 European countries
formulate policy on civil aviation issues, including safety, but do not
explicitly address passenger health issues. In addition, the European
Union issues legislation concerning aviation safety, certification, and
licensing requirements but has not adopted legislation specifically
related to passenger health. One European directive requires that all
member states assess and limit crewmembers' exposure to radiation from
their flight duties and provide them with information on the effects of
such radiation
exposure. The European Commission[Footnote 17] is also providing flight
crewmembers and other mobile workers with free health assessments prior
to employment, with follow-up health assessments at regular intervals.
Another European supplement to the ICAO framework is the Joint Aviation
Authorities (JAA), which represents the civil aviation regulatory
authorities of a number of European states[Footnote 18] that have
agreed to cooperate in developing and implementing common safety
regulatory standards and procedures. JAA uses staff of these
authorities to carry out its responsibilities for making,
standardizing, and harmonizing aviation rules, including those for
aviation safety, and for consolidating common standards among member
counties. In addition, JAA is to cooperate with other regional
organizations or national European state authorities to reach at least
JAA's safety level and to foster the worldwide implementation of
harmonized safety standards and requirements through the conclusion of
international arrangements.
Membership in JAA is open to members of the European Civil Aviation
Conference, which currently consists of 41 member countries. Currently,
37 countries are members or candidate members of JAA. JAA is funded by
national contributions; income from the sale of publications and
training; and income from other sources, such as user charges and
European Union grants. National contributions are based on indexes
related to the size of each country's aviation industry. The "largest"
countries (France, Germany, and the United Kingdom) each pay around 16
percent and the smallest around 0.6 percent of the total contribution
income. For 2003, JAA's total budget was about 6.6 million euros.
In early 1998, JAA launched the Safety Strategy Initiative to develop a
focused safety agenda to support the "continuous improvement of its
effective safety system" and further reduce the annual number of
accidents and fatalities regardless of the growth of air traffic. Two
approaches are being used to develop the agenda:
* The "historic approach" is based on analyses of past accidents and
has led to the identification of seven initial focus areas--controlled
flight into terrain, approach and landing, loss of control, design
related, weather, occupant safety and survivability, and runway safety.
* The "predictive approach" or "future hazards approach" is based on an
identification of changes in the aviation system.
JAA is cooperating in this effort with FAA and other regulatory bodies
to develop a worldwide safety agenda and avoid duplication of effort.
FAA has taken the lead in the historic approach, and JAA has taken the
lead in the future hazards approach.
JAA officials told us that they use a consensus-based process to
develop rules for aviation safety, including cabin occupant safety and
health-related issues. Reaching consensus among member states is time
consuming, but the officials said the time invested was worthwhile.
Besides making aviation-related decisions, JAA identifies and resolves
differences in word meanings and subtleties across languages--an effort
that is critical to reaching consensus. JAA does not have regulatory
rule-making authority. Once the member states are in agreement, each
member state's legislative authority must adopt the new requirements.
Harmonizing new requirements with U.S. and other international aviation
authorities further adds to the time required to implement new
requirements.
According to JAA officials, they use expert judgment to identify and
prioritize research and development efforts for aviation safety,
including airliner cabin occupant safety and health issues, but JAA
plans to move toward a more data-driven approach.[Footnote 19] While
JAA has no funding of its own for research and development, it
recommends research priorities to its member states. However, JAA
officials told us that member states' research and development efforts
are often driven by recent airliner accidents in the member states,
rather than by JAA's priorities. The planned shift from expert judgment
to a more data-driven approach will require more coordination of
aviation research and development across Europe. For example, in
January 2001, a stakeholder group formed by the European Commissioner
for Research issued a planning document entitled European Aeronautics:
A Vision for 2020, which, among other things, characterized European
aeronautics as a cross-border industry, whose research strategy is
shaped within national borders, leading to fragmentation rather than
coherence. The document called for better decision-making and more
efficient and effective research by the European Union, its member
states, and aeronautics stakeholders. JAA officials concurred with this
characterization of European aviation research and development.
Changes lie ahead for JAA and aviation safety in Europe. The European
Union recently created a European Aviation Safety Agency, which will
gradually assume responsibility for rule-making, certification, and
standardization of the application of rules by the national aviation
authorities. This organization will eventually absorb all of JAA's
functions and activities. The full transition from JAA to the safety
agency will take several years--per the regulation,[Footnote 20] the
European Aviation Safety Agency must begin operations by September 28,
2003, and transition to full operations by March 2007.
[End of section]
Appendix III: Summary of Key Actions FAA Has Taken to Improve Airliner
Cabin Safety and Health Since 1984:
Key improvement areas: Impact.
Key improvement areas: Stronger (16g) passenger seats; Action taken:
Impact: FAA required that seats for newly developed aircraft be
subjected to more rigorous testing than was previously required. The
tests subject seats to the forward, downward, and other directional
movements that can occur in an accident. Likely injuries under various
conditions are estimated by using instrumented crash test dummies;
Purpose: Impact: To improve the crashworthiness of airplane seats and
their ability to prevent or reduce the severity of head, back, and
femur injuries; Status: Impact: This rule was published on May 17,
1988, and became effective June 16, 1988. However, only the newest
generation of airplanes is required to have fully tested and
certificated 16g seats. FAA proposed a retrofit rule on October 4,
2002, to phase in 16g seats fleetwide within 14 years after adoption of
the final rule.
Key improvement areas: Overhead bins; Action taken: Impact: FAA issued
an airworthiness directive requiring corrective action for overhead bin
designs found not to meet the existing rules; Purpose: Impact: To
improve the crashworthiness of some bins after failures were observed
in a 1989 crash in Kegworth, England; Status: Impact: The
airworthiness directive to improve bin connectors became effective
November 20, 1992, and applied to Boeing 737 and 757 aircraft.
Key improvement areas: Fire.
Key improvement areas: More stringent flammability standards for
interior materials; Action taken: Impact: In 1986, FAA upgraded the
fire safety standards for cabin interior materials in transport
airplanes, establishing a new test method to determine the heat release
from materials exposed to radiant heat and set allowable criteria for
heat release rates; Purpose: Impact: To give airliner cabin occupants
more time to evacuate a burning airplane by limiting heat releases and
smoke emissions when cabin interior materials are exposed to fire;
Status: Impact: FAA required that all commercial aircraft produced
after August 20, 1988, have panels that exhibit reduced heat releases
and smoke emissions to delay the onset of flashover. Although there was
no retrofit of the existing fleet, FAA is requiring that these improved
materials be used whenever the cabin is substantially refurbished.
Key improvement areas: "Fire-blocking" seat cushions; Action taken:
Impact: In 1984, FAA issued a regulation that enhanced flammability
requirements for seat cushions; Purpose: Impact: To retard burning of
cabin materials to increase evacuation time; Status: Impact: This rule
applies to transport category aircraft after November 26, 1987.
Key improvement areas: Halon fire extinguishers; Action taken: Impact:
In March 1985, FAA issued a rule requiring at least two Halon fire
extinguishers on all commercial airliners, in addition to other
required extinguishers; Purpose: Impact: To extinguish in-flight
fires; Status: Impact: This rule became effective April 29, 1985, and
required compliance by April 29, 1986.
Key improvement areas: Smoke detectors in lavatories; Action taken:
Impact: In March 1985, FAA issued a rule requiring air carriers to
install smoke detectors in lavatories within 18 months; Purpose:
Impact: To identify and extinguish in-flight fires; Status: Impact:
This rule became effective on April 29, 1985, and required compliance
by October 29, 1986.
Key improvement areas: Fire extinguishers built in to lavatory waste
receptacles; Action taken: Impact: In March 1985, FAA required air
carriers to install automatic fire extinguishers in the waste paper
bins in all aircraft lavatories; Purpose: Impact: To identify and
extinguish prevent in-flight fires; Status: Impact: This rule became
effective on April 29, 1985; This rule required compliance by April
29, 1987.
Key improvement areas: Cargo compartment protection; Action taken:
Impact: In 1986, FAA upgraded the airworthiness standards for ceiling
and sidewall liner panels used in cargo compartments of transport
category airplanes; Purpose: Impact: To improve fire safety in the
cargo and baggage compartment of certain transport airplanes.[A];
Status: Impact: This rule required compliance on March 20, 1998.
Key improvement areas: Cargo compartment fire detection and
suppression; Action taken: Impact: In 1998, FAA required air carriers
to retrofit the U.S. passenger airliner fleet with fire detection and
suppression systems in certain cargo compartments. This rule applied to
over 3,400 airplanes in service and all newly manufactured airplanes;
Purpose: Impact: To improve fire safety in the cargo and baggage
compartment of certain transport airplanes.[A]; Status: Impact: This
rule became effective March 19, 1998, requiring compliance on March 20,
2001.
Key improvement areas: Evacuation.
Key improvement areas: Access to exits: Type III exits; Action taken:
Impact: This rule requires improved access to the Type III emergency
exits (typically smaller, overwing exits) by providing an unobstructed
passageway to the exit. Transport aircraft with 60 or more passenger
seats were required to comply with the new standards; Purpose: Impact:
To help ensure that passengers have an unobstructed passageway to exits
during an emergency; Status: Impact: This rule became effective June
3, 1992, requiring changes to be made by December 3, 1992.
Key improvement areas: Public address system: independent power source;
Action taken: Impact: This rule requires that the public address system
be independently powered for at least 10 minutes and that at least 5
minutes of that time is during announcements; Purpose: Impact: To
eliminate reliance on engine or auxiliary-power-unit operation for
emergency announcements; Status: Impact: This rule became effective
November 27, 1989, for air carrier and air taxi airplanes manufactured
on or after November 27, 1990.
Key improvement areas: Exit row seating; Action taken: Impact: This
rule requires that persons seated next to emergency exits be physically
and mentally capable of operating the exit and assisting other
passengers in emergency evacuations; Purpose: Impact: To improve
passenger evacuation in an emergency; Status: Impact: This rule became
effective April 5, 1990, requiring compliance by October 5, 1990.
Key improvement areas: Location of passenger emergency exits; Action
taken: Impact: Rule issued to limit the distance between adjacent
emergency exits on transport airplanes to 60 feet; Purpose: Impact: To
improve passenger evacuation in an emergency; Status: Impact: This
rule became effective July 24, 1989, imposing requirements on airplanes
manufactured after October 16, 1987.
Key improvement areas: Floor proximity emergency escape path marking;
Action taken: Impact: Airplane emergency lighting systems must visually
identify the emergency escape path and identify each exit from the
escape path; Purpose: Impact: To improve passenger evacuation when
smoke obscures overhead lighting; Status: Impact: This rule became
effective November 26, 1984, requiring implementation for large
transport airplanes by November 26, 1986.
Key improvement areas: Fire-resistant evacuation slides; Action taken:
Impact: Emergency evacuation slides manufactured after December 3,
1984, must be fire resistant and comply with new radiant heat testing
procedures.[B]; Purpose: Impact: To improve passenger evacuation;
Status: Impact: This technical standard became effective for all
evacuation slides manufactured after December 3, 1984.
Key improvement areas: General safety and health.
Key improvement areas: Preparation for in-flight emergencies; Action
taken: Impact: In 1986, FAA issued a rule requiring commercial airlines
to carry emergency medical kits; Purpose: Impact: To improve air
carriers' preparation for in-flight emergencies; Status: Impact: This
rule became effective August 1, 1986, requiring compliance as of that
date.
Key improvement areas: Ban on smoking for majority of domestic
commercial flights; Action taken: Impact: In 1988 and 1989, the
Congress passed legislation banning smoking on domestic flights of
varying durations; Purpose: Impact: To limit the impact of poor cabin
air quality on occupants' health; Status: Impact: These laws became
effective in 1988, and 1990, respectively.
Key improvement areas: Prevention of in-flight injuries; Action taken:
Impact: In June 1995, following two serious events involving
turbulence, FAA issued a public advisory to airlines urging the use of
seat belts at all times when passengers are seated but concluded that
existing rules did not require strengthening; ; In May 2000, FAA
instituted the Turbulence Happens public awareness campaign; Purpose:
Impact: To prevent passenger injuries from turbulence by increasing
public awareness of the importance of wearing seatbelts; Status:
Impact: Information is currently posted on FAA's Web site.
Source: GAO presentation of FAA information.
[A] Technical Class C category cargo compartments are required to have
built-in extinguishing systems to control fire in lieu of crewmember
accessibility. Class D category cargo compartments are required to
completely contain a fire without endangering the safety of the
airplane occupants.
[B] Standard Order (TSO)-C69B (''Emergency Evacuation Slides, Ramps,
Ramp/Slides, and Slide/Rafts'') prescribes minimum performance
standards for emergency evacuation slides, ramps, ramp/slides, and
slide/rafts, including standards for resistance to radiant heat
sources.
[End of table]
[End of section]
Appendix IV: Summaries of Potential Impact Safety Advancements:
This appendix presents information on the background and status of
potential advancements in impact safety that we identified, including
the following:
* retrofitting all commercial aircraft with more advanced seats,
* improving the ability of airplane floors to hold seats in an
accident,
* preventing overhead luggage bins from becoming detached or opening,
* requiring child safety restraints for children under 40 pounds, and:
* installing lap belts with self-contained inflatable air
bags.[Footnote 21]
Retrofitting All Commercial Aircraft with More Advanced Seats:
:
:
Background:
In commercial transport airplanes, the ability of a seat to protect a
passenger from the forces of impact in an accident depends on reducing
the forces of impact to levels that a person can withstand, either by
spreading the impact over a larger part of the person's body or by
decreasing the duration of the impact through the use of energy-
absorbing seats, an energy-absorbing fuselage and floors, or restraints
such as seat belts or inflatable seat belt air bags adapted from
automobile technology. In a 1996 study by R.G.W Cherry & Associates,
enhancing occupant restraint was ranked as the second most important of
33 potential ways to improve air crash survivability.[Footnote 22]
Boeing officials noted that the industry generally agrees with this
view but that FAA and the industry are at odds over the means of
implementing these changes.
According to an aviation safety expert, seats and restraints should be
considered as a system that involves:
* the seats themselves,
* seat restraints such as seat belts,
* seat connections to the floor,
* the spacing between seats, and:
* furnishings in the cabin area that occupants could strike in an
accident.
To protect the occupant, a seat must not only absorb energy well but
also stay attached to the floor of the aircraft. In other words, the
"tie-down" chain must remain intact. Although aircraft seat systems are
designed to withstand about 9 to 16 times the force of gravity, the
limits of human tolerance to impact substantially exceed the aircraft
and seat design limits. A number of seat and restraint devices have
been shown in testing to improve survivability in aviation accidents.
Several options are to retrofit the entire current fleet with fully
tested 16g seats, use rearward-facing seats, require three-point auto-
style seat belts with shoulder harnesses, and install auto-style air
bags.
FAA regulations require seats for newly certified airplane designs to
pass more extensive tests than were previously required to protect
occupants from impact forces of up to 16 times the force of normal
gravity in the forward direction; seat certification standards include
specific requirements to protect against head, spine, and leg injuries
(see fig. 5).[Footnote 23] FAA first required 16g seats and tests for
newly designed, certificated airplanes in 1988; new versions of
existing designs were not required to carry 16g seats.[Footnote 24]
Since 1988, however, in anticipation of a fleetwide retrofit rule,
manufacturers have increasingly equipped new airplanes with "16g-
compatible" seats that have some of the characteristics of fully
certified 16g seats.[Footnote 25] Certifying a narrow-body airplane
type to full 16g seat certification standards can cost
$250,000.[Footnote 26],[Footnote 27]
Figure 5: Coach Seating and Impact Position in Coach Seating:
[See PDF for image]
[End of figure]
In 1998 FAA estimated that 16g seats would avoid between about 210 to
410 fatalities and 220 to 240 serious injuries over the 20-year period
from 1999 through 2018. A 2000 study funded by FAA and the British
Civil Aviation Authority estimated that if 16g seats had been installed
in all airplanes that crashed from 1984 through 1998, between 23 to 51
fewer U.S. fatalities and 18 to 54 fewer U.S. serious injuries would
have occurred over the period. A number of accidents analyzed in that
study showed no benefit from 16g seats because it was assumed that 16g
seats would have detached from the floor, offering no additional
benefits compared with older seats.[Footnote 28] Worldwide, the study
estimated, about 333 fewer fatalities and 354 fewer serious injuries
would have occurred during the period had the improved seats been
installed. Moreover, if fire risks had been reduced, the estimated
benefits of 16g seats might have increased dramatically, as more
occupants who were assumed to survive the impact but die in the ensuing
fire would then have survived both the impact and fire.[Footnote 29]
Status:
Seats that meet the 16g certification requirements are currently
available and have been required on newly certificated aircraft designs
since 1988. However, newly manufactured airplanes of older
certification, such as Boeing 737s, 757s, or 767s, were not required to
be equipped with 16g certified seats. Recently, FAA has negotiated with
manufacturers to install full 16g seats on new versions of older
designs, such as all newly produced 737s.[Footnote 30] In October 2002,
FAA published a new proposal to create a timetable for all airplanes to
carry fully certified 16g seats within 14 years.[Footnote 31] The
comment period for the currently proposed rule ended in March 2003.
Under this proposal, airframe manufacturers would have 4 years to begin
installing 16g seats in newly manufactured aircraft only, and all
airplanes would have to be equipped with full 16g seats within 14 years
or when scheduled for normal seat replacement. FAA estimated that
upgrading passenger and flight attendant seats to meet full 16g
requirements would avert approximately 114 fatalities and 133 serious
injuries over 20 years following the effective date of the rule. This
includes 36 deaths that would be prevented by improvements to flight
attendant seats that would permit attendants to survive the impact and
to assist more passengers in an evacuation.
FAA estimated the costs to avert 114 fatalities and 133 serious
injuries at $245 million in present-value terms, or $519 million in
overall costs, which, according to FAA's analysis, would approximate
the monetary benefits from the seats.[Footnote 32] FAA estimated that
about 7.5 percent of airplane seats would have to be replaced before
they would ordinarily be scheduled for replacement. FAA's October 2002
proposal divides seats into three classes according to their
approximate performance level. Although FAA does not know how many
seats of each type seat are in service, it estimates that about 44
percent of commercial-service aircraft are equipped with full 16g
seats, 55 percent have 16g-compatible seats, and about 1 percent have
9g seats. The 16g-compatible or partial 16g seats span a wide range of
capabilities; some are nearly identical to full 16g seats but have been
labeled as 16g-compatible to avoid more costly certification, and other
partial 16g seats offer only minor improvements over the older
generation of 9g seats. To determine whether these seats have the same
performance characteristics as full 16g seats, it may be sufficient, in
some cases, to review the company's certification paperwork; in other
cases, however, full crash testing of actual 16g seats may be necessary
to determine the level of protection provided.
FAA is currently considering the comments it received on its October
2002 proposal. Industry comments raised concerns about general costs,
the costs of retrofitting flight attendant seats, and the possibility
that older airplanes designed for 9g seats might require structural
changes to accommodate full 16g seats. One comment expressed the desire
to give some credit for and "grandfather" in at least some partial 16g
seats.
Improving the Ability of Airplane Floors to Hold Seats in an Accident:
:
:
:
Background:
In an accident, a passenger's chances of survival depend on how well
the passenger cabin maintains "living space" and the passenger is "tied
down" within that space. Many experts and reports have noted floor
retention--the ability of the aircraft cabin floor to remain intact and
hold the passenger's seat and restraint system during a crash--as
critical to increasing the passenger's chances of survival. Floor
design concepts developed during the late 1940s and 1950s form the
basis for the cabin floors found in today's modern airplanes.
Accident investigations have documented failures of the floor system in
crashes.[Footnote 33] New 16g seat requirements were developed in the
1980s. 16g seats were intended to be retrofitted on aircraft with
traditional 9g floors and were designed to maximize the capabilities of
existing floor strength. While 16g seats might be strong, they could
also be inflexible and thus fail if the floor deformed in a crash.
Under the current 16g requirement, the seats must remain attached to a
deformed seat track and floor structure representative of that used in
the airplane.[Footnote 34] To meet these requirements, the seat was
expected to permanently deform to absorb and limit impact forces even
if the 16g test conditions were exceeded during a crash.
A major accident related to floor deformation occurred at Kegworth,
England, in 1989. A Boeing 737-400 airplane flew into an embankment on
approach to landing. In total, only 21 of the 52 triple seats--all
"16g-compatible" --remained fully attached to the cabin floor; 14 of
those that remained attached were in the area where the wing passes
through the cabin and the area is stronger than other areas to support
the wing.[Footnote 35] In this section of the airplane, the occupants
generally survived, even though they were exposed to an estimated peak
level of 26gs. The front part of the airplane was destroyed, including
the floor; most of these seats separated from the airplane, killing or
seriously injuring the occupants. An FAA expert noted that the impact
was too severe for the airplane to maintain its structural integrity
and that 16g seats were not designed for an accident of that severity.
The British Air Accidents Investigation Branch noted that fewer
injuries occurred in the accident than would probably have been the
case with earlier-generation seats. However, the Branch also noted that
"relatively minor engineering changes could significantly improve the
resilience and toughness of cabin floors . . . and take fuller
advantage of the improved passenger seats." The Branch reported that
where failures occurred, it was generally the seat track along the
floor that failed, and not the seat, and that the rear attachments
generally remained engaged with the floor, "at least partially due to
the articulated joint built into the rear attachment, an innovation
largely stemming from the FAA dynamic test requirements." The Branch
concluded that "seats designed to these dynamic requirements will
certainly increase survivability" but "do not necessarily represent an
optimum for the long term . . . if matched with cabin floors of
improved strength and toughness."[Footnote 36]
Status:
Several reports have recommended structural improvements to floors. A
case study of 11 major accidents for which detailed information was
available found floor issues to be a major cause of injury or
fatalities in 4 accidents and a minor cause in 1 accident. Another
study estimated the past benefits of 16g seats in U.S. accidents
between 1984 and 1998 and found no hypothetical benefit from 16g seats
in a number of accidents because the floor was extensively disrupted
during impact.[Footnote 37] In other words, unless the accidents had
been less severe or the floor and seat tracks had been improved beyond
the 9g standard on both new and old jets, newer 16g seats would not
have offered additional benefits compared with the older seats that
were actually on the airplane during the accidents under study.
A research program on seat and floor strength was recently conducted by
the French civil aviation authority, the Direction Générale de
l'Aviation Civile. Initial findings of the research program on seat-
floor attachments have not shown dramatic results and showed no rupture
or plastic deformation of any cabin floor parts during a 16g test.
However, French officials noted that they plan to perform additional
tests with more rigid seats. Because many factors are involved it is
difficult to identify the interrelated issues and interactions between
seats and floors. A possible area for future research, according to
French officials, is to examine dynamic floor warping during a crash to
improve impact performance.
FAA officials said they have no plans to change floor strength
requirements. FAA regulations require floors to meet impact forces
likely to occur in "emergency landing conditions," or generally about
9gs of longitudinal static force. According to several experts,
stronger floors could improve the performance of 16g seats. In
addition, further improvement in seats beyond the 16g standard would
likely require improved floors.
Preventing Overhead Storage Bin Detachment to Protect Passengers in an
Accident:
Background:
In an airplane crash, overhead luggage bins in the cabin sometimes
detach from their mountings along the ceiling and sidewalls and can
fall completely or allow pieces of luggage to fall on passengers' heads
(See fig. 6.). While only a few cases have been reported in which the
impact from dislodged overhead bins was the direct cause of a crash
fatality or injury, a study for the British Civil Aviation Authority
that attempted to identify the specific characteristics of each
fatality in 42 fatal accidents estimated that the integrity of overhead
bin stowage was the 17th most important of 32 factors used to predict
passenger survivability.[Footnote 38] Maintaining the integrity of bins
may also help speed evacuation after a crash.
Safer bins have been designed since bin problems were observed in a
Boeing 737 accident in Kegworth, England, in 1989, when nearly all the
bins failed and fell on passengers. FAA tested bins in response to that
accident. The Kegworth bins were certified to the current FAA 9g
longitudinal static loading standards, among others. When FAA
subsequently conducted longitudinal dynamic loading tests on the types
of Boeing bins involved, the bins failed. Several FAA experts said that
the overhead bins on 737s had a design flaw. FAA then issued an
airworthiness directive that called for modifying all bins on Boeing
737 and 757 aircraft. The connectors for the bins were strengthened in
accordance with the airworthiness directive, and the new bins passed
FAA's tests.
The British Air Accidents Investigation Branch recommended in 1990 that
the performance of both bins and latches be tested more rigorously,
including the performance of bins "when subjected to dynamic crash
pulses substantially beyond the static load factors currently
required." NTSB has made similar recommendations.
Turbulence reportedly injures at least 15 U.S. cabin occupants a year,
and possibly over 100. Most of these injuries are to flight attendants
who are unrestrained. Some injuries are caused by luggage falling from
bins that open in severe turbulence. Estimates of total U.S. airline
injuries from bin-related falling luggage range from 1,200 to 4,500
annually, most of which occur during cruising rather than during
boarding or disembarking.[Footnote 39]
The study for the British Civil Aviation Authority noted above found
that as many as 70 percent of impact-related accidents involve overhead
bins that become detached. However, according to the report, bin
detachment does not appear to be a major factor in occupants' survival
and data are insufficient to support a specific determination about the
mechanism of failure. FAA has conducted several longitudinal and drop
tests since the Kegworth accident, including drops of airplane fuselage
sections with overhead storage bins installed. A 1993 dynamic vertical
drop test showed some varying bin performance problems at about 36gs of
downward force. An FAA longitudinal test in 1999 tested two types of
bins at 6g, at the 9g FAA certification requirement, and at the 16g
level; in the 16g longitudinal test, one of the two bins broke free
from its support mountings.
Status:
In addition to the requirement that they withstand forward
(longitudinal) loads of slightly more than 9gs, luggage bins must meet
other directional loading requirements.[Footnote 40] Bin standards are
part of the general certification requirements for all onboard objects
of mass. FAA officials said that overhead bins no longer present a
problem, appear to function as designed, and meet standards. An FAA
official told us that problems such as those identified at Kegworth
have not appeared in later crashes. Another FAA official said that
while Boeing has had some record of bin problems, the problems are
occasional and quickly rectified through design changes. Boeing
officials told us that the evidence that bins currently have latch
problems is anecdotal.
Suggestions for making bins safer in an accident include adding
features to absorb impact forces and keep bins attached and closed
during structural deformation; using dynamic 16g longitudinal impact
testing standards similar to those for seats; and storing baggage in
alternative compartments in the main cabin, elsewhere in the aircraft,
or under seats raised for that purpose.
Child Safety Seats:
:
Background:
Using a correctly-designed child safety seat that is strapped in an
airplane seat offers protection to a child in an accident or turbulence
(see fig. 6). By contrast, according to many experts, holding a child
under two years old on an adult's lap, which is permitted, is unsafe
for both the child and for other occupants who could be struck by the
child in an accident. Requiring child safety seats for infants and
small children on airplanes is one of NTSB's "most wanted"
transportation safety improvements. The British Air Accidents
Investigation Branch made similar recommendations, as did a 1997 White
House Commission report on aviation.
Figure 6: Examples of Child Safety Seats:
[See PDF for image]
[End of figure]
:
An FAA analysis of survivable accidents from 1978 through 1994 found
that 9 deaths, 4 major injuries, and 8 minor injuries to children
occurred. The analysis also found that the use of child safety seats
would have prevented 5 deaths, all the major injuries, and 4 to 6 of
the minor injuries. Child safety advocates have pointed to several
survivable accidents in which children died--a 1994 Charlotte, North
Carolina, crash; a 1990 Cove Neck, New York, accident; and a 1987
Denver, Colorado, accident--as evidence of the need for regulation.
A 1992 FAA rule required airlines to allow child restraint systems, but
FAA has opposed mandatory child safety seats on the basis of studies
showing that requiring adults to pay for children's seats would induce
more car travel, which the study said was more dangerous for children
than airplane travel. One study published in 1995 by DOT estimated that
if families were charged full fares for children's seats, 20 percent
would choose other modes of transportation, resulting in a net increase
of 82 deaths among children and adults over 10 years.
If child safety seats are required, airlines may require adults wishing
to use child safety seats to purchase an extra seat for the child's
safety seat. FAA officials told us that they could not require that the
seat next to a parent be kept open for a nonpaying child. However, NTSB
has testified that the scenarios for passengers taking other modes of
transportation are flawed because FAA assumed that airlines would
charge full fares for infants currently traveling free. NTSB noted in
1996 that airlines would offer various discounts and free seats for
infants in order to retain $6 billion in revenue that would otherwise
be lost to auto travel. Airlines have already responded to parents who
choose to use child restraint systems with scheduling flexibility, and
many major airlines offer a 50 percent discount off any fare for a
child under 2 to travel in an approved child safety seat. The 1995 DOT
study, however, estimated that even if a child's seat on an airplane
were discounted 75 percent, some families would still choose car travel
and that the choice by those families to drive instead of fly would
result in a net increase of 17 child and adult deaths over 10 years.
In FAA tests, some but not all commercially available automobile child
restraint systems have provided adequate protection in tests simulating
airplane accidents. Prices range from less than $100 for a child safety
seat marketed for use in both automobiles and airplanes to as much as
$1,300 for a child safety seat developed specifically for use in
airplanes.
A drawback to having parents, rather than airlines, provide child
safety seats for air travel is that some models may be more difficult
to fit into airplane seat belts, making a proper fit more challenging.
While the performance of standardized airline-provided seats may be
better than that of varied FAA-certified auto-airplane seats, one
airline said that providing seats could present logistical problems for
them. However, Virgin Atlantic Airlines supplies its own specially
developed seats and prohibits parents from using their own child seats.
Because turbulence can be a more frequent danger to unrestrained
children than accidents, one expert told us that a compromise solution
might include allowing some type of alternative in-flight restraint.
Status:
Child safety seats are currently available for use on aircraft. The
technical issues involved in designing and manufacturing safe seats for
children to use in both cars and airplanes have largely been solved,
according to FAA policy officials and FAA researchers. Federal
regulations establish requirements for child safety seats designed for
use in both highway vehicles and aircraft by children weighing up to 50
pounds. FAA officials explained that regulations requiring child safety
seats have been delayed, in part, because of public policy concerns
that parents would drive rather than fly if they were required to buy
seats for their children. On February 18, 1998, FAA asked for comments
on an advanced notice of proposed rule-making to require the use of
child safety seats for children under the age of 2. FAA sponsored a
conference in December 1999 to examine child restraint systems. At that
conference, the FAA Administrator said the agency would mandate child
safety seats in aircraft and provide children with the same level of
safety as adults. FAA officials told us that they are still considering
requiring the use of child safety seats but have not made a final
decision to do so. If FAA does decide to provide "one level of safety"
for adults and children, as NTSB advocates, parents may opt to drive to
their destinations to avoid higher travel costs, thereby statistically
exposing themselves and their children to more danger. In addition, FAA
will have to decide whether the parents or airlines will provide the
seats.
If FAA decides to require child safety seats, it will need to harmonize
its requirements with those of other countries where requirements
differ, as the regulations on child restraint systems vary. In Canada,
as in the United States, child safety seats are not mandatory on
registered aircraft. In Europe, the regulations vary from country to
country, but no country requires their use. Australia's policy permits
belly belts but discourages their use. An Australian official said in
1999 that Australia was waiting for the United States to develop a
policy in this area and would probably follow that policy.
Inflatable Lap Belt Air Bags:
:
Background:
Lap belts with inflatable air bags are designed to reduce the injuries
or death that may result when a passenger's head strikes the airplane
interior. These inflatable seat belts adapt advanced automobile air bag
technology to airplane seats in the form of seat belts with embedded
air bags. If a passenger loses consciousness because of a head injury
in an accident, even a minor, nonfatal concussion can cause death if
the airplane is burning and the passenger cannot evacuate quickly.
Slowing the duration of the impact with an air bag lessens its
lethality. According to a manufacturer's tests using airplane seats on
crash sleds, lap belts with air bags can likely reduce some impact
injuries to survivable levels.[Footnote 41]
FAA does not require seats to be tested in sled tests for head impact
protection when there would be "no impact" with another seat row or
bulkhead wall, such as when spacing is increased to 42 inches from the
more typical 35 inches. While more closely spaced economy class seat
rows can provide head impact protection through energy-absorbing seat
backs, seats in no impact positions have tested poorly in head injury
experiments, resulting in severe head strikes against the occupants'
legs or the floor, according to the manufacturer. This no impact
exemption from FAA's head injury criteria can include exit rows,
business class seats, and seats behind bulkhead walls and could permit
as many as 30 percent of seats in some airplanes to be exempt from the
head impact safety criteria that row-to-row seats must meet.
Status:
According to the manufacturer, 13 airlines have installed about 1,000
of the devices in commercial airliners, mainly at bulkhead seats; about
200 of these are installed in the U.S. fleet. All of the orders and
installations so far have been done to meet FAA's seat safety
regulations rather than for marketing reasons, according to the
manufacturer.
The airlines would appear to benefit from using the devices in bulkhead
seats if that would allow them to install additional rows of seats.
While the amount of additional revenue would depend on the airplane
design and class of seating, two additional seats may produce more net
revenue per year than the cost for the devices to be installed
throughout an aircraft.[Footnote 42] Economic constraints are
acquisition costs, maintenance costs, and increased fuel costs due to
weight. The units currently weigh about 3 pounds per seat, or 2 pounds
more than current seat belts. According to the manufacturer, the air
bag lap belts currently cost $950 to $1,100, including maintenance. The
manufacturer estimated that if 5 percent of all U.S. seat positions
were equipped with the devices (about 50,000 seats per year), the cost
would drop to about $300 to $600 per seat, including
installation.[Footnote 43]
Lap belt air bags have been commercially available for only a few
years. FAA's Civil Aerospace Medical Institute assisted the developers
of the devices; manufacturers for both passenger and military use
(primarily helicopter) are conducting ongoing research. FAA and other
regulatory bodies have no plans to require their installation, but
airlines are allowed to use them. The extent to which these devices are
installed will depend on each airline's analysis of the cost and
benefits.
[End of section]
Appendix V: Summaries of Potential Fire Safety Advancements:
This appendix presents information on the background and status of
potential advancements in fire safety that we identified, including the
following:
* preventing fuel tank explosions with fuel tank inerting;
* preventing in-flight fires with arc fault circuit breakers;
* identifying in-flight fires with multisensor fire and smoke
detectors;
* suppressing in-flight and postcrash fires by using water mist fire
suppression systems;
* mitigating postcrash damage and injury by using less flammable fuels;
* mitigating in-flight and postcrash fires by using fire-resistant
thermal acoustic insulation;
* mitigating fire-related deaths and injuries by using ultra-fire-
resistant polymers; and:
* mitigating fire deaths and injuries with sufficient airport rescue
and fire fighting.
Fuel Tank Inerting:
:
Background:
Fuel tank inerting involves pumping nitrogen-enriched air into an
airliner's fuel tanks to reduce the concentration of oxygen to a level
that will not support combustion. Nitrogen gas makes a fuel tank safer
by serving as a fire suppressant. The process can be performed with
both ground-based and onboard systems, and it significantly reduces the
flammability of the center wing tanks, thereby lowering the likelihood
of a fuel tank explosion.
Following the crash of TWA Flight 800 in 1996, in which 230 people
died, NTSB determined that the probable cause of the accident was an
explosion in the center wing fuel tank. The explosion resulted from the
ignition of flammable fuel vapors in this tank, which is located in the
fuselage in the space between the wing junctions. NTSB subsequently
placed the improvement of fuel tank design on its list of "Most Wanted
Safety Improvements" and recommended that fuel tank inerting be
considered an option to eliminate the likelihood of fuel tank
explosions.
FAA issued Special Federal Aviation Regulation 88[Footnote 44] to
eliminate or minimize the likelihood of ignition sources by revisiting
the fuel tank's design. Issued in 2001, the regulation consists of a
series of FAA regulatory actions aimed at preventing the failure of
fuel pumps and pump motors, fuel gauges, and electrical power wires
inside these fuel tanks. In late 2002, FAA amended the regulation to
allow for an "equivalent level of safety" and the use of inerting as
part of an alternate means of compliance.
In a 2001 report, an Aviation Rule-making Advisory Committee tasked
with evaluating the benefits of inerting the center wing fuel tank
estimated these benefits in terms of lives saved. After projecting
possible in-flight and ground fuel tank explosions and postcrash fires
from 2005 through 2020, the committee estimated that 132 lives might be
saved from a ground-based system and 253 lives might be saved from an
onboard system.[Footnote 45]
Status:
Neither of the two major types of fuel tank inerting--ground-based and
onboard--is currently available for use on commercial airliners because
additional development is needed.[Footnote 46] Both types offer
benefits and drawbacks.
* A ground-based system sends a small amount of nitrogen into the
center wing tank before departure. Its benefits include that (1) it
requires no new technology development for installation, (2) the tank
can be inerted in 20 minutes, and (3) it carries a lesser weight
penalty. Its drawbacks include that it is unable to inert for descent,
landing, and taxiing to the destination gate, and nitrogen supply
systems are needed at each terminal gate and remote parking area at
every airport.
* An onboard system generates nitrogen by transferring some of the
engine bleed air - air extracted from the jet engines to supply the
cabin pressurization system in normal flight--through a module that
separates air into oxygen and nitrogen and discharges the nitrogen
enriched air into the fuel tank. Its benefits include that (1) it is
self-reliant and (2) it significantly reduces an airplane's
vulnerability to lightning, static electricity, and incendiary
projectiles throughout the flight's duration.[Footnote 47] Its
drawbacks include that it (1) weighs more, (2) increases the aircraft's
operating costs, and (3) may decrease the aircraft's
reliability.[Footnote 48]
According to FAA, its fire safety experts' efforts to develop a
lighter-weight system for center wing tank inerting have significantly
increased the industry's involvement. Boeing and Airbus are working on
programs to test inerting systems in flight. For example, Boeing has
recently completed a flight test program with a prototype system on a
747.
None of the U.S. commercial fleet is equipped with either ground-based
or onboard inerting systems, though onboard systems are in use in U.S.
and European military aircraft. Companies working in this field are
focused on developing new inerting technologies or modifying existing
ones. A European consortium is developing a system that combines
onboard center wing fuel tank inerting with sensors and a water-mist-
plus-nitrogen fire suppression system for commercial airplanes.
In late 2002, FAA researchers successfully ground-tested a prototype
onboard inerting system using current technology on a Boeing 747SP. New
research also enabled the agency to ease a design requirement, making
the inerting technology more cost-effective. This new research showed
that reducing the oxygen level in the fuel tank to 12 percent--rather
than 9 percent, as was previously thought--is sufficient to prevent
fuel tank explosions in civilian aircraft.[Footnote 49] FAA also
developed a system that did not need the compressors that some had
considered necessary. Together, these findings allowed for reductions
in the size and power demands of the system.
FAA plans to focus further development on the more practical and cost-
effective onboard fuel tank inerting systems. For example, to further
improve their cost-effectiveness, the systems could be designed both to
suppress in-flight cargo fires, thereby allowing them to replace Halon
extinguishing agents, and to generate oxygen for emergency
depressurizations, thereby allowing them to replace stored oxygen or
chemical oxygen generators.
NASA is also conducting longer-term research on advanced technology
onboard inert gas-generating systems and onboard oxygen-generating
systems. Its research is intended (1) to develop the technology to
improve its efficiency, weight, and reliability and (2) to make the
technology practical for commercial air transport. NASA will fund the
development of emerging technologies for ground-based technology
demonstration in fiscal year 2004. NASA is also considering the
extension of civilian transport inerting technology to all fuel tanks
to help protect airplanes against terrorist acts during approaches and
departures.
The cost of the system, its corresponding weight, and its unknown
reliability are the most significant factors affecting the potential
use of center wing fuel tank inerting. New cost and weight estimates
are anticipated in 2003.
* In 2001, FAA estimated total costs to equip the worldwide fleet at
$9.9 billion for ground-based, and $20.8 billion for onboard, inerting
systems.[Footnote 50]
* In 2002, FAA officials developed an onboard system for B-747 flight-
testing. The estimated cost was $460,000. The officials estimated that
each system after that would cost about $200,000. The weight of the FAA
prototype system is 160 pounds.[Footnote 51] A year earlier, NASA
estimated the weight for a B-777 system with technology in use in
military aircraft at about 550 pounds.[Footnote 52]
Arc Fault Circuit Breaker:
:
Background:
Arcing faults in wiring may provide an ignition source that can start
fires. Electrical wiring that is sufficiently damaged might cause
arcing or direct shorting resulting in smoking, overheating, or
ignition of neighboring materials. A review of data produced by FAA,
the Airline Pilots Association, and Boeing showed that electrical
systems have been a factor in approximately 50 percent of all aircraft
occurrences involving smoke or fire and that wiring has been implicated
in about 10 percent of those occurrences. In addition, faulty or
malfunctioning wiring has been a factor in at least 15 accidents or
incidents investigated by NTSB since 1983. Properly selecting, routing,
clamping, tying, replacing, marking, separating, and cleaning around
wiring areas and proper maintenance all help mitigate the potential for
wire system failures, such as arcing, that could lead to smoke, fire
and loss of function. Chemical degradation, age induced cracking, and
damage due to maintenance may all create a scenario which could lead to
arcing. Arcing can occur between a wire and structure or between
different wire types. Wire chafing is a sign of degradation; chafing
happens when the insulation around one wire rubs against a component
tougher than itself (such as structure or control cable) exposing the
wire conductor. This condition can lead to arcing. When arcing wires
are too close to flammable materials or are flammable themselves, fires
can occur.
In general, wiring and wiring insulation degrade for a variety of
reasons, including age, inadequate maintenance, chemical
contamination, improper installation or repair, and mechanical damage.
Vibration, moisture, and heat can contribute to and accelerate
degradation. Consequences of wire systems failures include loss of
function, smoke, and fire. Since most wiring is bundled and located in
hidden or inaccessible areas, it is difficult to monitor the health of
an aircraft's wiring system during scheduled maintenance using existing
equipment and procedures. Failure occurrences have been documented in
wiring running to the fuel tank, in the electronics equipment
compartment, in the cockpit, in the ceiling of the cabin, and in other
locations.
To address the concerns with arcing, arc fault circuit breakers for
aircraft use are being developed. The arc fault circuit breaker cuts
power off as it senses a wire beginning to arc. It is intended to
prevent significant damage before a failure develops into a full-blown
arc, which can produce extremely localized heat, char insulation, and
generally create problems in the wire bundles. Arc fault circuit
protection devices would mitigate arcing events, but will not identify
the wire breaches and degradation that typically lead up to these
events.
Status:
FAA, the Navy, and the Air Force are jointly developing arc fault
circuit breaker technology. Boeing is also developing a monitoring
system to detect the status of and changes in wiring; and power shuts
down when arcing is detected. This system may be able to protect wiring
against both electrical overheating and arcing and is considered more
advanced than the government's circuit breaker technology.
FAA developed a plan called the Enhanced Airworthiness Program for
Airplane Systems to address wiring problems, which includes development
of arc fault circuit breaker technology and installation guidance along
with proposals of new regulations. The plan provides means for
enhancing safety in the areas of wire system design, certification,
maintenance, research and development, reporting, and information
sharing and outreach. FAA also tasked an Aging Transport Systems Rule-
making Advisory Committee to provide data, recommendations, and
evaluation specifically on aging wiring systems. The new regulations
being considered are entitled the Enhanced Airworthiness Program for
Airplane Systems Rule and are expected by late-2005. Under this rule-
making package, inspections would evaluate the health of wiring and all
of its components for operation, such as connectors and clamps. Part of
the system includes visual inspections of all wiring within arm's
reach, enhanced by the use of hand-held mirrors. This improvement is
expected to catch more wiring flaws than current visual inspection
practices. Where visual inspections can not be assumed to detect
damage, detailed inspections will be required. The logic process to
establish proper inspections is called the Enhanced Zonal Analysis
Procedure, which will be issued as an Advisory Circular. This procedure
is specifically directed towards enhancing the maintenance programs for
aircraft whose current program does not include tasks derived from a
process that specifically considers wiring in all zones as the
potential source of ignition of a fire.
Additional development and testing will be required before advanced arc
fault circuit breakers will be available for use on aircraft. The FAA
currently is in the midst of a prototype program where arc fault
circuit breakers are installed in an anticollision light system on a
major air carrier's Boeing 737. The FAA and the Navy are currently
analyzing tests of the circuit breakers to assess their reliability.
The Society of Automotive Engineers is in the final stages of
developing a Minimum Operating Performance Specification for the arc
fault circuit breaker.
Multisensor Detectors:
:
Background:
Multisensor detectors, or "electronic noses," could combine one or more
standard smoke detector technologies; a variety of sensors for
detecting such gases as carbon monoxide, carbon dioxide, or
hydrocarbon; and a thermal sensor to more accurately detect and locate
overheated or burning materials. The sensors could improve existing
fire detection by discovering and locating potential or actual fires
sooner and reducing the incidence of false alarms. These "smart"
sensors would ignore the "nuisance sources":
:
such as dirt, dust, and condensation that are often responsible for
triggering false alarms in existing systems.[Footnote 53]
According to studies by FAA and the National Institute of Standards and
Technology, many current smoke and fire detection systems are not
reliable. A 2000 FAA study indicated that cargo compartment detection
systems, for example, resulted in at least one false alarm per week
from 1988 through 1990 and a 200:1 ratio of false alarms to actual
fires in the cargo compartment from 1995 through 1999. [Footnote 54]
FAA has since estimated a 100:1 cargo compartment false alarm ratio,
partly because reported actual incidents have increased According to
FAA's Service Difficulty Report database,[Footnote 55] about 990 actual
smoke and fire events were reported for 2001.[Footnote 56]
Multisensor detectors could be wired or wireless and linked to a
suppression system. One or several sensor signals or indicators could
cause the crew to activate fire extinguishers in a small area or zone,
a larger area, or an entire compartment, resulting in a more
appropriate and accurate use of the fire suppressant. For example, in
areas such as the avionics compartment, materials that can burn are
relatively well-defined. Multisensor detectors the size of a postage
stamp could be designed to detect smoldering fires in cables or
insulation or in overheated equipment in that area. Placing the
detectors elsewhere in the airplane could improve the crew's ability to
respond to smoke or fire, including occurrences in hidden or
inaccessible areas.
Improved sensor detection technologies would both enhance safety by
increasing crews' confidence in the reliability of alarms and reduce
costs by avoiding the need to divert aircraft in response to false
alarms. One study estimated the average cost of a diversion at $50,000
for a wide-body airplane and $30,000 for a narrow-body airplane. A
diversion can also present safety concerns because of the possible
increased risk of an accident and injuries to passengers and crew if
there is (1) an emergency evacuation, (2) a landing at an unfamiliar
airport, (3) a change to air traffic patterns, (4) a shorter runway,
(5) inferior fire-fighting capability, (6) a loss of cargo load, or (7)
inferior navigation aids. In 2002, 258 unscheduled landings due to
smoke, fire, or fumes occurred. In addition, 342 flights were
interrupted; some of these flights had to return to the gate or abort a
takeoff.
FAA established basic detector performance requirements in 1965 and
1980. Detectors were to be made and installed in a manner that ensured
their ability to resist, without failure, all vibration, inertia, and
other loads to which they might normally be subjected; they also had to
be unaffected by exposure to fumes, oil, water, or other fluids.
Regulations in 1986 and 1998 further defined basic location and
performance requirements for detectors in different areas of the cargo
compartment. In 1998, FAA issued a requirement for detection and
extinguishment systems for one class of cargo compartments, which
relied on oxygen starvation to control fires. This requirement
significantly increased the number of detectors in use.
Status:
Multisenor detectors are not currently available because additional
research is needed. Although they have been demonstrated in the
laboratory and on the ground, they have not been flight-tested. FAA and
NASA have multisensor detector research and development efforts under
way and are working to develop "smart" sensors and criteria for their
approval. FAA will also finish revising an Advisory Circular that
establishes test criteria for detection systems, designed to ensure
that they respond to fires, but not to nonfire sources. In addition,
several companies currently market "smart" detectors, mostly for
nonaviation applications. For example, thermal detection systems sense
and count certain particles that initially boil off the surface of
smoldering or burning material.
A European consortium has been developing a system, FIREDETEX, that
combines the use of multisensor detectors, onboard fuel tank inerting,
and water-mist-plus-nitrogen fire suppression systems for commercial
airplanes. This program and associated studies are still ongoing and
flight testing is planned for the last quarter of calendar year 2003.
The results of tests on this system are expected to be made public in
early 2004, and will help to clarify the possible costs, benefits, and
drawbacks of the combined system.
Additional research, development, and testing will be required before
multisensor technology is ready for use in commercial aviation. NASA,
FAA, and private companies are pursuing various approaches. Some
experts believe that some forms of multisensor technology could be in
use in 5 years. When these units become available, questions may arise
about where their use will be required. For example, the Canadian
Transportation Safety Board has recommended that some areas in addition
to those currently designated as fire zones may need to be equipped
with detectors.[Footnote 57] These include the electronics and
equipment bay (typically below the floor beneath the cockpit and in
front of the passenger cabin), areas behind interior wall panels in the
cockpit and cabin areas, and areas behind circuit breaker and other
electronic panels.
Water Mist Fire Suppression:
:
Background:
For over two decades, the aviation industry has evaluated the use of
systems that spray water mist to suppress fires in airliner cabins,
cargo compartments, and engine casings (see fig. 7). This effort was
prompted, in part, by a need to identify an alternative to Halon, the
primary chemical used to extinguish fires aboard airliners. With few
exceptions, Halon is the sole fire suppressant installed in today's
aircraft fire suppression systems. However, the production of Halon was
banned under the 1987 Montreal Protocol on Substances that Deplete the
Ozone Layer, and its use in many noncritical sectors has been phased
out. Significant reserves of Halon remain, and its use is still allowed
in certain "critical use" applications, such as aerospace,[Footnote 58]
because no immediate viable replacement agent exists. To enable the
testing and further development of suitable alternatives to and
substitutes for Halon, FAA has drafted detailed standards for
replacements in the cargo and engine compartments. These standards
typically require replacement systems to provide the same level of
safety as the currently used Halon extinguishing system.
Figure 7: Water Mist Nozzle and Possible Placement:
[See PDF for image]
[End of figure]
According to FAA and others in the aviation industry, successful water
mist systems could provide benefits against an in-flight or postcrash
fire, including:
* cooling the passengers, cabin surfaces, furnishings and overall cabin
temperatures;
* decreasing toxic smoke and irritant gases; and:
* delaying or preventing "flashover" fires from occurring.[Footnote 59]
In addition, a 1996 study prepared for the British Civil Aviation
Authority examined 42 accidents and 32 survivability factors and found
that cabin water spray was the factor that showed the greatest
potential for reducing fatality and injury rates.[Footnote 60] In the
early 1990s, a joint FAA and Civil Aviation Authority study found that
cabin water mist systems would be highly effective in improving
survivability during a postcrash fire.[Footnote 61] However, the cost
of using these systems outweighed the benefits, largely because of the
weight of the water that airliners would be required to carry to
operate them. In the mid-and late-1990s, FAA and others began examining
water mist systems in airliner cargo compartments to help offset the
cost of a cabin water mist system because the water could be used or
shared by both the cargo compartment and the cabin. European and U.S.
researchers also designed systems that required much less water because
they targeted specific zones within an aircraft to suppress fires
rather than spraying water throughout the cabin or the cargo
compartment.
In 2000, Navy researchers found a twin-fluid system to be highly
reliable and maintenance-free.[Footnote 62] Moreover, this system's
delivery nozzles could be installed without otherwise changing cabin
interiors. The Navy researchers' report recommended that FAA and NTSB
perform follow-up testing leading to the final design and certification
of an interior water mist fire suppression system for all passenger and
cargo transport aircraft. Also in 2000, a European consortium began a
collaborative research project
called FIREDETEX, which combines multisensor fire detectors, water
mist, and onboard fuel tank inerting into one fire detection and
suppression system.[Footnote 63]
In 2001 and 2002, FAA tested experimental mist systems to determine
what could meet its preliminary minimum performance standards for cargo
compartment suppression systems. A system that combines water mist with
nitrogen met these minimum standards. In this system, water and
nitrogen "knock down" the initial fire, and nitrogen suppresses any
deep-seated residual fire by inerting the entire compartment.[Footnote
64] In cargo compartment testing, this system maintained cooler
temperatures than had either a plain water mist system or a Halon-based
system.
Status:
Additional research and testing are needed before water mist technology
can be considered for commercial aircraft. For example, the weight and
relative effectiveness of any water mist system would need to be
considered and evaluated. In addition, before it could be used in
aircraft, the consequences of using water will need to be further
evaluated. For example, Boeing officials noted that using a water mist
fire suppression system in the cabin in a post crash fire might
actually reduce passenger safety if the mist or fog creates confusion
among the passengers, leading to longer evacuation times. Further, of
concern is the possible shorting of electrical wiring and equipment and
damage to aircraft interiors (e.g., seats, entertainment equipment, and
insulation). Water cleanup could also be difficult and require special
drying equipment.
Fire-Safe Fuels:
:
Background:
Burning fuel typically dominates and often overwhelms postcrash fire
scenarios and causes even the most fire-resistant materials to
burn.[Footnote 65] Fuel spilled from tanks ruptured upon crash impact
often forms an easily ignitable fuel-air mixture. A more frequent fuel-
related problem is the fuel tank explosion, in which a volatile fuel-
air mixture inside the fuel tank is ignited, often by an unknown
source. For example, it is believed that fuel tank explosions destroyed
a Philippines Air 737 in 1990, TWA Flight 800 in 1996, and a Thai Air
737 in 2001. Therefore, reducing the flammability of fuel could improve
survivability in postcrash fires as well as reduce the occurrence of
fuel tank explosions.
Reducing fuel flammability involves limiting the volatility[Footnote
66] of fuel and the rate at which it vaporizes.[Footnote 67] Liquid
fuel can burn only when enough fuel vapor is mixed with air. If the
fuel cannot vaporize, a fire cannot occur. This principle is behind the
development of higher-flashpoint fuel, whose use can decrease the
likelihood of a fuel tank explosion. The flash point is the lowest
temperature at which a liquid fuel produces enough vapor to ignite in
the presence of a source of ignition--the lower the flash point, the
greater the risk of fire. If the fuel is volatile enough, however, and
air is sucked into the fuel tank area upon crash impact, limiting the
fuel's vaporization can prevent a burnable mixture from forming. This
principle supports the use of additives that modify the viscosity of
fuel to limit postcrash fires; for example, antimisting kerosene
contains such additives. According to FAA and NASA, however, these
additives do nothing to prevent fuel tank explosions.
From the early 1960s to the mid-1980s, FAA conducted research on fuel
safety. The Aviation Safety Act of 1988 required that FAA undertake
research on low-flammability aircraft fuels, and, in 1993, FAA
developed plans for fuel safety research. In 1996, a National Research
Council experts' workshop on aviation fuel summarized existing fuel
safety research efforts. The participants concluded that although
postcrash fuel-fed aircraft fires had been researched, limited progress
had been achieved and little work had been published.
As part of FAA's research, fuels have been modified with thickening
polymer additives to slow down vaporization in crashes. Participants in
the 1996 National Research Council workshop identified several long-
term research goals for consideration in developing modified fuels and
fuel additives to improve fire safety. They also agreed that a
combination of effective fire-safe fuel additives could probably be
either selected or designed, provided that fuel performance
requirements were identified in advance. In addition, they agreed that
existing aircraft designs that reduce the chance of fuel igniting do
not present major barriers to the implementation of a fire-safe fuel.
A 1996 European Transport Safety Council report suggested that
antimisting kerosene be at least partially tested on regular military
transport flights (e.g., in one tank, feeding one engine) to
demonstrate its operational compatibility. The report also recommended
the consideration of a study comparing the costs of the current
principal commercial fuel and the special, higher-flashpoint fuel used
by the Navy. According to NASA and FAA fire-safe fuels experts,
military fuel is much harder to burn in storage or to ignite in a pan
because of its lower volatility; however, it is just as flammable as
aviation fuel when it is sprayed into an engine combustor.
Status:
Fire-safe fuels are not currently available and are in the early stages
of research and development. In January 2002, NASA opened a fire-safe
fuels research branch at its Glenn Research Center in Ohio. NASA-Glenn
is conducting aviation fuel research that evaluates fuel vapor
flammability in conjunction with FAA's fuel tank inerting program,
including the measurement of fuel "flash points." NASA is examining the
effects of
surfactants, gelling agents, and chemical composition changes on the
vaporization and pressure characteristics of jet fuel.[Footnote 68]
In addition to FAA's and NASA's research, some university and industry
researchers have made progress in developing fire-safe fuels. Many use
advanced analytical, computational modeling technologies to inform
their research. A council of producers and users of fuels is also
coordinating research on ways to use such fuels. NASA fuel experts
remain optimistic that small changes in fuel technologies can have a
big impact on fuel safety.
Developing fire-safe fuels will require much more research and testing.
There are significant technical difficulties associated with creating a
fuel that meets aviation requirements while meaningfully decreasing the
flammability of the fuel.
Thermal Acoustic Insulation Materials:
:
Background:
To keep an airplane quieter and warmer, a layer of thermal acoustic
insulation material is connected to paneling and walls throughout the
aircraft. This insulation, if properly designed, can also prevent or
limit the spread of an in-flight fire. In addition, thermal acoustic
insulation provides a barrier against a fire burning through the cabin
from outside the airplane's fuselage (See fig. 8.). Such a fire, often
called a postcrash fire, may occur when fuel is spilled on the ground
after a crash or an impact.
Figure 8: Fire Insulation Blankets:
[See PDF for image]
[End of figure]
While this thermal acoustic insulation material could help prevent the
spread of fire, some of the insulation materials that have been used in
the past have contributed to fires. For example, FAA indicated that an
insulation material, called metallized Mylar®, contributed to at least
six in-flight fires. Airlines have stopped using this material and are
removing it from existing aircraft.
FAA's two main efforts in this area are directed toward preventing
fatal in-flight fire and improving postcrash fire survivability.
* Since 1998, FAA has been developing test standards for preventing in-
flight fires in response to findings that fire spread on some thermal
acoustic insulation blanket materials. In 2000, FAA issued a notice of
proposed rule-making that outlined new flammability test criteria for
in-flight fires. FAA's in-flight test standards require thermal
acoustic insulation materials to protect passengers. According to the
standards, insulation materials installed in airplanes will not
propagate a fire if ignition occurs.
* FAA is also developing more stringent burnthrough test standards for
postcrash fires. FAA has been studying the penetration of the fuselage
by an external fire--known as fuselage burnthrough--since the late
1980s and believes that improving the fire resistance of thermal
acoustic insulation could delay fuselage burnthrough. In laboratory
tests conducted from 1999 through 2002, an FAA-led working group
determined that insulation is the most potentially effective and
practical means of delaying the spread of fire or creating a barrier to
burnthrough. In 2002, FAA completed draft burnthrough standards
outlining a proposed methodology for testing thermal acoustic
insulation. The burnthrough standards would protect passengers and
crews by extending by at least 4 minutes the time available for
evacuation in a postcrash fire.
Various studies have estimated the potential benefits from both test
standards:
* A 1999 study of worldwide aviation accidents from 1966 through 1993
estimated that about 10 lives per year would have been saved if
protection had provided an additional 4 minutes for occupants to exit
the airplane.
* A 2000 FAA study estimated that about 37 U.S. fatalities would be
avoided between 2000 and 2019 through the implementation of both
proposed standards.[Footnote 69]
* A 2002 study by the British Civil Aviation Authority of worldwide
aviation accidents from 1991 through 2000 estimated that at least 34
lives per year would have been saved if insulation had met both
proposed standards.
Status:
Insulation designed to replace metallized Mylar® is currently
available. A 2000 FAA airworthiness directive gave the airlines 5 years
to remove and replace metallized Mylar® insulation in 719 affected
airplanes. Replacement insulation is required to meet the in-flight
standard and will be installed in these airplanes by mid-2005. In that
airworthiness directive, FAA indicated that it did not consider other
currently installed insulation to constitute an unsafe condition.
Thermal acoustic insulation is currently available for installation on
commercial airliners. This insulation has been demonstrated to reduce
the chance of fatal in-flight fires and to improve postcrash fire
survivability. On July 31, 2003, FAA issued a final rule requiring that
after September 2, 2005, all newly manufactured airplanes having a
seating capacity of more than 20 passengers or over 6,000 pounds must
use thermal acoustic insulation that meets more stringent standards for
how quickly flames can spread.[Footnote 70] In addition, for aircraft
of this size manufactured before September 2, 2003, replacement
insulation in the fuselage must also meet the new, higher standard.
Research is continuing to develop thermal acoustic insulation that
provides better in-flight and burnthrough protection. Even when this
material is available, the high cost of retrofitting airplanes may
limit its use to newly manufactured aircraft. For example, FAA
estimates that the metallized Mylar® retrofit alone will cost a total
of $368.4 million, discounted to present value terms, for the 719
affected airplanes. Because thermal acoustic insulation is installed
throughout the pressurized section of the airplane for the life of its
service, retrofitting the entire fleet would cost several billion
dollars.
Ultra-Fire-Resistant Polymers:
:
Background:
Polymers are used in aircraft in the form of lightweight plastics and
composites and are selected on the basis of their estimated installed
cost, weight, strength, and durability. Most of the aircraft cabin is
made of polymeric material. In the event of an in-flight or a postcrash
fire, the use of polymeric materials with reduced flammability could
give passengers and crew more time to evacuate by delaying the rate at
which the fire spreads through the cabin.
FAA researchers are developing better techniques to measure the
flammability of polymers and to make polymers that are ultra fire
resistant. Developing these materials is the long-term goal of FAA's
Fire Research Program, which, if successful, will "eliminate burning
cabin materials as a cause of death in aircraft accidents." Materials
being improved include composite and adhesive resins, textile fibers,
rubber for seat cushions, and plastics for molded parts used in seats
and passenger electronics. (See fig. 9.):
Figure 9: Flammable Cabin Materials and Small-scale Material Test
Device:
[See PDF for image]
[End of figure]
Adding flame-retardant substances to existing materials is one way to
decrease their flammability. For example, some manufacturers add
substances that release water when they reach a high temperature. When
a material, such as wiring insulation, is heated or burns, the water
acts to absorb the heat and cools down the fire. Other materials are
designed to become surface-scorched on exposure to fire, causing a
layer of char to protect the rest of the material from burning. Lastly,
adding a type of clay can have a flame-retardant effect. In general,
these fire-retardant polymers are formulated to pass an ignition test
but do not meet FAA's criterion for ultra fire resistance, which is a
90 percent reduction in the rate at which the untreated material would
burn. To meet this strict requirement, FAA is developing new "smart"
polymers that are typical plastics under normal conditions but convert
to ultra-fire-resistant materials when exposed to an ignition source or
fire.
FAA has adopted a number of flammability standards over the last 30
years. In 1984, FAA passed a retrofit rule that replaced 650,000 seat
cushions with flame-retardant seat cushions at a total cost of about
$75 million. The replacement seat cushions were found to delay cabin
flashover by 40 to 60 seconds. Fire-retardant seat cushions can also
prevent ramp and in-flight fires that originate at a seat and would
otherwise burn out of control if left unattended. In 1986 and 1988, FAA
set maximum allowable levels of heat and smoke from burning interior
materials to decrease the amount of smoke that they would release in a
postcrash fire. These standards affected paneling in all newly
manufactured aircraft. Airlines and airframe manufacturers invested
several hundred million dollars to develop these new panels.
Status:
Ultra-fireresistant polymers are not currently available for use on
commercial airliners. These polymers are still in the early stages of
research and development. To reduce the cost and simplify the testing
of new materials, FAA is employing a new technique to characterize the
flammability and thermal decomposition of new products; this technique
requires only a milligram of sample material. The result has been the
discovery of several new compositions of matter (including "smart"
polymers). The test identifies key thermal and combustion properties
that allow rapid screening of new materials.[Footnote 71] From these
materials, FAA plans to select the most promising and work with
industry to make enough of the new polymers to fabricate full-scale
cabin components like sidewalls and stowage bins for fire testing.
FAA's phased research program includes the selection in 2003 of a small
number of resins, plastics, rubbers, and fibers on the basis of their
functionality, cost, and potential to meet fire performance guidelines.
In 2005, FAA plans to fabricate decorative panels, molded parts, seat
cushions, and textiles for testing from 2007 through 2010. Full-scale
testing is scheduled for 2011 but is contingent upon the availability
of program funds and commercial interest from the private sector.
Research continues on ultra-fire-resistant polymers that will increase
protection against in-flight fires and cabin burnthrough. According to
an FAA fire research expert, issues facing this research include (1)
the current high cost of ultra-fire-resistant polymers; (2)
difficulties in producing ultra-fire-resistant polymers with low to
moderate processing temperatures, good strength and toughness, and
colorability and colorfastness; and (3) gaps in understanding the
relationship between material properties and fire performance and
between chemical composition and fire performance, scaling
relationships, and fundamental fire-resistance mechanisms. In
addition, once the materials are developed and tested, getting them
produced economically and installed in aircraft will become an issue.
It is expected that such new materials with ultra fire resistance would
be more expensive to produce and that the market for such materials
would be uncertain.
Airport Rescue and Fire-Fighting Operations:
:
Background:
Because of the fire danger following a commercial airplane crash,
having airport rescue and fire-fighting operations available can
improve the chances of survival for the people involved. Most airplane
accidents occur during takeoff or landing at the airport or in the
surrounding community. A fire outside the airplane, with its tremendous
heat, may take only a few minutes to burn through the airplane's
outside shell. According to FAA, firefighters are responsible for
creating an escape path by spraying water and chemicals on the fire to
allow the passengers and crew to evacuate the airplane. Firefighters
use one or more trucks to extinguish external fires, often at great
personal risk, and use hand-held attack lines when attempting to put
out fires within the airplane fuselage. (See fig. 10). Fires within the
fuselage are considered difficult to control with existing equipment
and procedures because they involve complex conditions, such as smoke-
laden toxic gases and high temperatures in the passenger cabin. FAA has
taken actions to control both internal and external postcrash fires,
including requiring major airports to have airport rescue and fire-
fighting operations.
Figure 10: Airport Rescue and Fire Training:
[See PDF for image]
[End of figure]
In 1972, FAA first proposed regulations to ensure that major airports
have a minimal level of airport rescue and fire-fighting operations.
Some changes to these regulations were made in 1988. The regulations
establish, among other things, equipment standards, annual testing
requirements for response times, and operating procedures. The
requirements depend on both the size of the airport and the resources
the locality has agreed to make available as needed.
In 1997, FAA compared airport rescue and fire-fighting missions and
standards for civilian airports with DOD's for defense installations
and reported that DOD's requirements were not applicable to civilian
airports. In 1988, and again in 1998, Transport Canada Civil Aviation
also studied its rescue and fire-fighting operations and concluded that
the expenditure of resources for such unlikely occurrences was
difficult to justify from a benefit-cost perspective. This conclusion
highlighted the conflict between safety and cost in attempting to
define rescue and fire-fighting requirements.
A coalition of union organizations and others concerned about aviation
safety released a report critical of FAA's standards and operational
regulations in 1999. According to the report, FAA's airport rescue and
fire-fighting regulations were outdated and inadequate.
Status:
In 2002, FAA incorporated measures recommended by NTSB into FAA's
Aeronautical Information Manual Official Guide to Basic Flight
Information and Air Traffic Control Procedures.[Footnote 72] These
measures (1) designate a radio frequency at most major airports to
allow direct communication between airport rescue and fire-fighting
personnel and flight crewmembers in the event of an emergency and (2)
specify a universal set of hand signals for use when radio
communication is lost.
In March 2001, FAA responded to the reports criticizing its airport
rescue and fire-fighting standards by tasking its Aviation Regulatory
Advisory Committee to review the agency's rescue and fire-fighting
requirements to identify measures that could be added, modified, or
deleted. In 2003, the committee is expected to propose requirements for
the number of trucks, the amount of fire extinguishing agent, vehicle
response times, and staffing at airports and to publish its findings in
a notice of proposed rule-making. Depending on the results of this FAA
review, additional resources may be needed at some airports. The
overall cost of improving airport rescue and fire-fighting response
capabilities could be a significant barrier to the further development
of regulations. For example, some in the aviation industry are
concerned about the costs of extending requirements to smaller airports
and of appropriately equipping all airports with resources. According
to FAA, extending federal safety requirements to some smaller airports
would cost at least $2 million at each airport initially and $1 million
annually thereafter.
[End of section]
Appendix VI: Summaries of Potential Improved Evacuation Safety
Advancements:
This appendix presents information on the background and status of
potential advancements in evacuation safety that we identified,
including the following:
* improved passenger safety briefings;
* exit seat briefings;
* photo-luminescent floor track marking;
* crewmember safety and evacuation training;
* acoustic attraction signals;
* smoke hoods;
* exit slide testing;
* overwing exit doors;
* evacuation procedures for very large transport aircraft; and:
* personal flotation devices.
Passenger Safety Briefings:
:
Background:
Federal regulations require that passengers receive an oral briefing
prior to takeoff on safety aspects of the upcoming flight. FAA also
requires that oral briefings be supplemented with printed safety
briefing cards that pertain only to that make and model of airplane and
are consistent with the air carrier's procedures. These two safety
measures must include information on smoking, the location and
operation of emergency exits, seat belts, compliance with signs, and
the location and use of flotation devices. In addition, if the flight
operates above 25,000 feet mean sea level, the briefing and cards must
include information on the emergency use of oxygen.
FAA published an Advisory Circular in March 1991 to guide air carriers'
development of oral safety briefings and cards. Primarily, the circular
defines the material that must be covered and suggests material that
FAA believes should be covered. The circular also discusses the
difficulty in motivating passengers to attend to the safety information
and suggests making the oral briefing and safety cards as attractive
and interesting as possible to increase passengers' attention. The
Advisory Circular suggests, for example, that flight attendants be
animated, speak clearly and slowly, and maintain eye contact with the
passengers. Multicolored safety cards with pictures and drawings should
be used over black and white cards. Finally, the circular suggests the
use of a recorded videotape briefing because it ensures a complete
briefing with good diction and allows for additional visual information
to be presented to the passengers. (See fig. 11.):
Figure 11: Airline Briefing to Passengers on Safety Briefing Cards:
[See PDF for image]
[End of figure]
Status:
Despite efforts to improve passengers' attention to safety information,
a large percentage of passengers continue to ignore preflight safety
briefings and safety cards, according to a study NTSB conducted in
1999. Of 457 passengers polled, 54 percent (247) reported that they had
not watched the entire briefing because they had seen it before. An
additional 70 passengers indicated that the briefing provided common
knowledge and therefore there was no need to watch it. Of 431
passengers who answered a question about whether they had read the
safety card, 68 percent (293) indicated that they had not, many of them
stating that they had read safety cards on previous flights.
Safety briefings and cards serve an important safety purpose for both
passengers and crew. They are intended to prepare passengers for an
emergency by providing them with information about the location and
operation of exits and emergency equipment that they may have to
operate--and whose location and operation may differ from one airplane
to the next. Well-briefed passengers will be better prepared in an
emergency, thereby increasing their chances of surviving and lessening
their dependence on the crew for assistance.
In its emergency evacuation study, NTSB recommended that FAA instruct
airlines to "conduct research and explore creative and effective
methods that use state-of-the-art technology to convey safety
information to passengers."[Footnote 73] NTSB further recommended "the
presented information include a demonstration of all emergency
evacuation procedures, such as how to open the emergency exits and exit
the aircraft, including how to use the slides." That research found
that passengers often view safety briefings and cards as uninteresting
and the information as intuitive. FAA has requested that commercial
carriers explore different ways to present the materials to their
passengers, adding that more should be done to educate passengers about
what to do after an accident has occurred.
Exit Seat Briefing:
:
Background:
Passengers seated in an exit row may be called on to assist in an
evacuation. Upon a crewmember's command or a personal assessment of
danger, these passengers must decide if their exit is safe to use and
then open their exit hatch or door for use during an evacuation. In
October 1990, FAA required airlines to actively screen passengers
occupying exit seats for "suitability" and to administer one-on-one
briefings on their responsibilities. This rule does not require
specific training for exit seat occupants, but it does require that the
occupants be duly informed of their distinct obligations.
Status:
According to NTSB, preflight briefings of passengers in exit rows could
contribute positively to a passenger evacuation. In a 1999 study, NTSB
found that the individual briefings given to passengers who occupy exit
seats have a positive effect on the outcome of an aircraft evacuation.
The studies also found that as a result of the individualized
briefings, flight attendants were better able to assess the suitability
of the passengers seated in the exit seats.
According to FAA's Flight Standards Handbook Bulletin for Air
Transportation, several U.S. airlines have identified specific cabin
crewmembers to perform "structured personal conversations or
briefings," designed to equip and prepare passengers in exit seats
beyond the general passenger briefing. Also, the majority of air
carriers have procedures to assist crewmembers with screening
passengers seated in exit rows.
FAA's 1990 rule requires that passengers seated in exit rows be
provided with information cards that detail the actions to be taken in
the case of an emergency. However, individual exit row briefings, such
as those recommended by NTSB, are not required. Also included on the
information cards are provisions for a passenger who does not wish to
be seated in the exit row to be reseated. Additionally, carriers are
required to assess the exit row passenger's ability to carry out the
required functions. The extent of discussion with exit row passengers
depends on each airline's policy.
Photo-luminescent Floor Track Marking:
:
Background:
In June 1983, an Air Canada DC-9 flight from Dallas to Toronto was
cruising at 33,000 feet when the crew reported a lavatory fire. An
emergency was declared, and the aircraft made a successful emergency
landing at the Cincinnati Northern Kentucky International Airport. The
crew initiated an evacuation, but only half of the 46 persons aboard
were able to escape before becoming overcome by smoke and fire. In its
investigation of this accident, NTSB learned that many of the 23
passengers who died might have benefited from floor tracking lighting.
As a result, NTSB recommended that airlines be equipped with floor-
level escape markings. FAA determined that floor lighting could improve
the evacuation rate by 20 percent under certain conditions, and FAA now
requires all airliners to have a row of lights along the floor to guide
passengers to the exit should visibility be reduced by smoke.
On transport category aircraft, these escape markings, called floor
proximity marking systems, typically consist primarily of small
electric lights spaced at intervals on the floor or mounted on the seat
assemblies, along the aisle. The requirement for electricity to power
these systems has made them vulnerable to a variety of problems,
including battery and wiring failures, burned-out light bulbs, and
physical disruption caused by vibration, passenger traffic, galley cart
strikes, and hull breakage in accidents. Attempts to overcome these
problems have led to the proposal that nonelectric, photo-luminescent
(glow-in-the-dark) materials be used in the construction of floor
proximity marking systems. The elements of these new systems are
"charged" by the normal airplane passenger cabin lighting, including
the sunlight that enters the cabin when the window shades are open
during daylight hours. (See fig. 12.):
Figure 12: Floor Track Marking Using Photo-luminescent Materials:
[See PDF for image]
[End of figure]
Status:
Floor track marking using photo-luminescent materials is currently
available but not required for U.S. commercial airliners. Performance
demonstrations of photo-luminescent technology have found that
strontium aluminate photo-luminescent marking systems can be effective
in providing the guidance for egress that floor proximity marking
systems are intended to achieve. According to industry and government
officials, such photo-luminescent marking systems are also cheaper to
install than electric light systems and require little to no
maintenance. Moreover, photo-luminescent technology weighs about 15 to
20 pounds less than electric light systems and, unlike the electric
systems, illuminates both sides of the aisle, creating a pathway to the
exits.
Photo-luminescent floor track marking technology is mature and is
currently being used by a small number of operators, mostly in Europe.
In the United States, Southwest Airlines has equipped its entire fleet
with the photo-luminescent system. However, the light emitted from
photo-luminescent materials is not as bright as the light from
electrically operated systems. Additionally, the photo-luminescent
materials are not as effective when they have not been exposed to light
for an extended period of time, as after a long overseas nighttime
flight. The estimated retail price of an entire system, not including
the installation costs, is $5,000 per airplane.
Crewmember Safety and Evacuation Training:
:
Background:
FAA requires crewmembers to attend annual training to demonstrate their
competency in emergency procedures. They have to be knowledgeable and
efficient while exercising good judgment. Crewmembers must know their
own duties and responsibilities during an evacuation and be familiar
with those of their fellow workers so that they can take over for
others if necessary.
The requirements for emergency evacuation training and demonstrations
were first established in 1965. Operators were required to conduct
full-scale evacuation demonstrations, include crewmembers in the
demonstrations, and complete the demonstrations in 2 minutes using 50
percent of the exits. The purpose of the demonstrations was to test the
crewmembers' ability to execute established emergency evacuation
procedures and to ensure the realistic assignment of functions to the
crew. A full-scale demonstration was required for each type and model
of airplane when it first started passenger-carrying operations,
increased its passenger seating capacity by 5 percent or more, or
underwent a major change in the cabin interior that would affect an
emergency evacuation. Subsequently, the time allowed to evacuate the
cabin during these tests was reduced to 90 seconds.
The aviation community took steps in the 1990s to develop a program
called Crew Resource Management that focuses on overall improvements in
crewmembers' performance and flight safety strategies, including those
for evacuation. FAA officials told us that they plan to emphasize the
importance of effective communication between crewmembers and are
considering updating a related Advisory Circular. Effective
communication between cockpit and cabin crew are particularly important
with the added security precautions being taken after September 11,
2001, including the locking the cockpit door during flight.
Status:
The traditional training initiative now has an advanced curriculum,
Advanced Crew Resource Management. According to FAA, this comprehensive
implementation package includes crew resource management procedures,
training for instructors and evaluators, training for crewmembers, a
standardized assessment of the crew's performance, and an ongoing
implementation process. This advanced training was designed and
developed through a collaborative effort between the airline and
research communities. FAA considers training to be an ongoing
development process that provides airlines with unique crew resource
management solutions tailored to their operational demands. The design
of crew resource management procedures is based on principles that
require an emphasis on the airline's specific operational environment.
The procedures were developed to emphasize these crew resource
management elements by incorporating them into standard operating
procedures for normal as well as abnormal and emergency flight
situations.
Because commercial airliner accidents are rare, crewmembers must rely
on their initial and recurrent training to guide their actions during
an emergency. Even in light of advances and initiatives in evacuation
technology, such as slides and slide life rafts, crewmembers must still
assume a critical role in ensuring the safe evacuation of their
passengers. Airline operators have indicated that it is very costly for
them to pull large numbers of crewmembers off-line to participate in
training sessions.
FAA officials told us that improving flight and cabin crew
communication holds promise for ensuring the evacuation of passengers
during an emergency. To improve this communication and coordination
between flight and cabin crew, FAA plans to update the related Advisory
Circular, oversee training, and charge FAA inspectors with monitoring
air carriers during flights to see that improvements are being
implemented. In addition, FAA is enhancing its guidance to air carriers
on preflight briefings for flight crews to sharpen their responses to
emergency situations and mitigate passengers' confusion. FAA expects
this guidance to bolster the use and quality of preflight briefings
between pilots and flight attendants on security, communication, and
emergency procedures. According to FAA, these briefings have been shown
to greatly improve the flight crew's safety mind-set and to enhance
communication.
Acoustic Attraction Signals:
:
Background:
Acoustic attraction signals make sounds to help people locate the doors
in smoke, darkness, or when lights and exit signs are obscured. When
activated, the devices are intended to help people to determine the
direction and approximate distance of the sound--and of the door.
Examples of audio attraction signals include recorded speech sounds,
broadband multifrequency sounds ("white noise"), or alarm bells.
Research to determine if acoustic attraction signals can be useful in
aircraft evacuation has included, for example, FAA's Civil Aeromedical
Institute testing of recorded speech sounds in varying pitches, using
phrases such as "This way out," "This way," and "Exit here."
Researchers at the University of Leeds developed Localizer Directional
Sound beacons, which combine broadband, multifrequency "white noise" of
between 40Hz and 20kHz with an alerting sound of at least one other
frequency, according to the inventor (see fig. 13).
Figure 13: Test Installation of Acoustic Signalling Device:
[See PDF for image]
Note: Acoustic signaling device is of the type used near building
exits.
[End of figure]
The FAA study noted above of acoustic attraction signals found that in
the absence of recorded speech signals, the majority of participants
evacuating a low-light-level, vision-obscured cabin will head for the
front exit or will follow their neighbors. In contrast, participants
exposed to recorded speech sounds will select additional exits, even
those in the rear of the airplane. During aircraft trials conducted by
Cranfield University and University of Greenwich researchers, tests of
directional sound beacons found that under cabin smoke conditions,
exits were used most efficiently when the cabin crew gave directions
and the directional sound beacons were activated. With this
combination, the distribution of passengers to the available exits was
better than with cabin crew directions alone, sound beacons alone, no
cabin crew directions, or no sound beacons. Researchers found that
passengers were able to identify and move toward the closest sound
source inside the airplane cabin and to distinguish between two closely
spaced loudspeakers. However, in 2001, Airbus conducted several
evacuation test trials of audio attraction signals using an A340
aircraft. According to Airbus, the acoustic attraction signals did not
enhance passengers' orientation, and, overall, did not contribute to
passengers' safety.
Status:
While acoustic attraction signals are currently available, further
research is needed to determine if their use is warranted on commercial
airliners. FAA, Transport Canada Civil Aviation, and the British
Civilian Aviation Authority do not currently mandate the use of
acoustic attraction signals. The United Kingdom's Air Accidents
Investigation Branch made a recommendation after the fatal Boeing 737
accident at Manchester International Airport in 1985 that research be
undertaken to assess the viability of audio attraction signals and
other evacuation techniques to assist passengers impaired by smoke and
toxic or irritant gases. The Civilian Aviation Authority accepted the
recommendation and sponsored research at Cranfield University; however,
it concluded from the research results that the likely benefit of the
technology would be so small that no further action should be taken,
and the recommendation was closed in 1992.
The French Direction Generale de l'Aviation Civile funded aircraft
evacuation trials using directional sound beacons in November 2002,
with oversight by the European Joint Aviation Authorities. The trials
were conducted at Cranfield University's evacuation simulator with
British Airways cabin crew and examined eight trial evacuations by two
groups of 'passengers.' The study surveyed the participants' views on
various aspects of their evacuation experience and measured the overall
time to evacuate. The speed of evacuation was found to be biased by the
knowledge passengers' gained in the four successive trials, and by
variations in the number of passengers participating on the 2 days (155
and 181). The four trials by each of the two groups of passengers also
involved different combinations of crew and sound in each. The study
concluded that the insufficient number of test sessions further
contributed to bias in the results, and that further research would be
needed to determine whether the devices help to speed overall
evacuation.
Further research and testing are needed before acoustic attraction
signals can be considered for widespread airline use. The signals may
have drawbacks that would need to be addressed. For example, the Civil
Aviation Authority found that placing an audio signal in the bulkhead
might disorient or confuse the first few passengers who have to pass
and then move away from the sound source to reach the exit. Such
hesitation slowed passengers' evacuation during testing. The
researchers at Cranfield University trials in 1990 concluded that an
acoustic sound signal did not improve evacuation times by a
statistically significant amount, suggesting that the device might not
be cost-effective.
Smoke Hoods:
:
Background:
Smoke hoods are designed to provide the user with breathable, filtered
air in an environment of smoke and toxic gases that would otherwise be
incapacitating. More people die from smoke and toxic gases than from
fire after an air crash. Because only a few breaths of the dense, toxic
smoke typically found in aircraft fires can render passengers
unconscious and prevent their evacuation, the wider use of smoke hoods
has been investigated as a means of preventing passengers from being
overcome by smoke and of giving them enough breathable air to evacuate.
However, some studies have found that smoke hoods are only effective in
certain types of fires and in some cases may slow the evacuation of
cabin occupants.
As shown in figure 14, a filter smoke hood can be a transparent bag
worn over the head that fits snugly at the neck and is coated with
fire-retardant material; it has a filter but no independent oxygen
source and can provide breathable air by removing some toxic
contaminants from the air for a period ranging from several minutes to
15 minutes, depending on the severity and type of air contamination.
The hood has a filter to remove carbon monoxide--a main direct cause of
death in fire-related commercial airplane accidents, as well as
hydrogen cyanide--another common cause of death, sometimes from
incapacitation that can prevent evacuation. Hoods also filter carbon
dioxide, chlorine, ammonia, acid gases such as hydrogen chloride and
hydrogen sulfide, and various hydrocarbons, alcohols, and other
solvents. Some hoods also include a filter to block particulate matter.
One challenge is where to place the hoods in a highly accessible
location near each seat.
Figure 14: An Example of a Commercially Available Smoke Hood:
[See PDF for image]
[End of figure]
Certain smoke hoods have been shown to filter out many contaminants
typically found in smoke from an airplane cabin fire and to provide
some temporary head protection from the heat of fire. In a full-scale
FAA test of cabin burnthrough, toxic gases became the driving factor
determining survivability in the forward cabin, reaching lethal levels
minutes before the smoke and temperature rose to unsurvivable levels.
A collaborative effort to estimate the potential benefits of smoke
hoods was undertaken in 1986 by the British Civil Aviation Authority
(CAA), the Federal Aviation Administration, the Direction Générale de
l'Aviation Civile (France) and Transport Canada Civil Aviation. The
resulting 1987 study examined the 20 accidents where sufficient data
was available out of 74 fire-related accidents worldwide from 1966 to
1985. The results were sensitive to assumptions regarding extent of use
and delays due to putting on smoke hoods. The study concluded that
smoke hoods could significantly extend the time available to evacuate
an aircraft and would have saved approximately 179 lives in the 20
accidents studied, assuming no delay in donning smoke hoods. Assuming a
10 percent reduction in the evacuation rate due to smoke hood use would
have resulted in an estimated 145 lives saved in the 20 accidents with
adequate data. A 15 second delay in donning the hoods would have saved
an estimated 97 lives in the 20 accidents.[Footnote 74] When the
likelihood of use of smoke hoods was included in the analysis for each
accident, the total net benefit was estimated at 134 lives saved in the
20 accidents. The study also estimated that an additional 228 lives
would have been saved in the 54 accidents where less data was
available, assuming no delay in evacuation.[Footnote 75]
The U.S. Air Force and a major manufacturer are developing a drop-down
smoke hood with oxygen. Because current oxygen masks in airplanes are
not airtight around the mouth, they provide little protection from
toxic gases and smoke in an in-flight fire. To provide protection from
these hazards, as well as from decompression and postcrash fire and
smoke, the Air Force's drop-down smoke hood with oxygen uses the
airplane's existing oxygen system and can fit into the overhead bin of
a commercial airliner where the oxygen mask is normally stowed. This
smoke hood is intended to replace current oxygen masks but also be
potentially separated from the oxygen source in a crash to provide time
to evacuate.
Status:
Smoke hoods are currently available and produced by several
manufacturers; however, not all smoke hoods filter carbon monoxide.
They are in use on many military and private aircraft, as well as in
buildings. An individually-purchased filter smoke hood costs about $70
or more, but according to one manufacturer bulk order costs have
declined to about $40 per hood. In addition, they estimated that hoods
cost about $2 a year to install and $5 a year to maintain. They weigh
about a pound or less and have to be replaced about every 5 years.
Furthermore, airlines could incur additional replacement costs due to
theft if smoke hoods were placed near passenger seats in commercial
aircraft.
Neither the British CAA, the FAA, the DGAC, nor Transport Canada Civil
Aviation has chosen to require smoke hoods. The British Air Accident
Investigations Branch recommended that smoke hoods be considered for
aircraft after the 1985 Manchester accident, in which 48 of 55
passengers died on a runway from an engine fire before takeoff, mainly
from smoke inhalation and the effects of hydrogen cyanide.
Additionally, a U.K. parliamentary committee recommended research into
smoke hoods in 1999, and the European Transport Safety Council, an
international nongovernmental organization whose mission is to provide
impartial advice on transportation safety to the European Commission
and Parliaments, recommended in 1997 that smoke hoods be provided in
all commercial aircraft. Canada's Transportation Safety Board has taken
no official position on smoke hoods, but has noted a deficiency in
cabin safety in this area and recommended further evaluation of
voluntary passenger use.
Although smoke hoods are currently available, they remain
controversial. Passengers are allowed to bring filter type smoke hoods
on an airplane, but FAA is not considering requiring airlines to
provide smoke hoods for passengers. The debate over whether smoke hoods
should be installed in aircraft revolves mainly around regulatory
concerns that passengers will not be able to put smoke hoods on quickly
in an emergency; that hoods might hinder visibility, and that any delay
in putting on smoke hoods would slow down an evacuation. FAA's and
CAA's evacuation experiments--to determine how long it takes for
passengers to unpack and don smoke hoods and whether an evacuation
would be slowed by their use--have reached opposite conclusions about
the effects of smoke hoods on evacuation rates. The CAA has noted that
delays in putting on smoke hoods by only one or two people could
jeopardize the whole evacuation. An opposite view by some experts is
that the gas and smoke-induced incapacitation of one or two passengers
could also delay an evacuation.
FAA believes that an evacuation might be hampered by passengers'
inability to quickly and effectively access and don smoke hoods, by
competitive passenger behavior, and by a lack of passenger
attentiveness during pre-flight safety briefings. FAA noted that smoke
hoods can be difficult to access and use even by trained individuals.
However, other experts have noted that smoke hoods might reduce panic
and help make evacuations more orderly, that competitive behavior
already occurs in seeking access to exits in a fire, and that
passengers could learn smoke hood safety procedures in the pre-flight
safety briefings in the same way they learn to use drop-down oxygen
masks or flotation devices.
The usefulness of smoke hoods varies across fire scenarios depending on
assumptions about how fast hoods could be put on and how much time
would be available to evacuate. One expert told us that the time needed
to put on a smoke hood might not be important in several fire
scenarios, such as an in-flight fire in which passengers are seeking
temporary protection from smoke until the airplane lands and an
evacuation can begin. In other scenarios--a ground evacuation or
postcrash evacuation --some experts argue that passengers in back rows
or far from an exit may have their exit path temporarily blocked as
other passengers exit and, because of the delay in their evacuation,
may have a greater need and more time available to don smoke hoods than
passengers seated near usable exits.
Exit Slide Testing:
:
Background:
Exit slide systems are rarely used during their operational life span.
However, when such a system is used, it may be under adverse crash
conditions that make it important for the system to work as designed.
To prevent injury to passengers and crew escaping through floor-level
exits located more than 6 feet above the ground, assist devices (i.e.,
slides or slide-raft systems) are used. (See fig. 15.):
Figure 15: Drawing of Possible Emergency Slide Testing of FAA's 747
Test Aircraft:
[See PDF for image]
[End of figure]
The rapid deployment, inflation, and stability of evacuation slides are
important to the effectiveness of an aircraft's evacuation system, as
was illustrated in the fatal ground collision of a Northwest Airlines
DC-9 and a Northwest Airlines 727 in Romulus, Michigan, in December
1990. As a result of the collision, the DC-9 caught fire, but there
were several slide problems that slowed the evacuation. For example,
NTSB later found that the internal tailcone exit release handle was
broken, thereby preventing the tailcone from releasing and the slide
from deploying.
Because of concerns about the operability of exit slides, NTSB
recommended in 1974 that FAA improve its maintenance checks of exit
slide operations. In 1983, FAA revised its exit slide requirements to
specify criteria for resistance to water penetration and absorption,
puncture strength, radiant heat resistance, and deployment as flotation
platforms after ditching.
Status:
All U.S. air carriers have an FAA-approved maintenance program for each
type of airplane that they operate. These programs require that the
components of an airplane's emergency evacuation system, which includes
the exit slides, be periodically inspected and serviced. An FAA
principal maintenance inspector approves the air carrier's maintenance
program. According to NTSB, although most air carriers' maintenance
programs require that a percentage of emergency evacuation slides or
slide rafts be tested for deployment, the percentage of required on-
airplane deployments is generally very small. For example, NTSB found
that American Airlines' FAA-approved maintenance program for the A300
requires an on-airplane operational check of four slides or slide rafts
per year. Delta Air Lines' FAA-approved maintenance program for the L-
1011 requires that Delta activate a full set of emergency exits and
evacuation slides or slide rafts every 24 months. Under an FAA-approved
waiver for its maintenance program, United is not required to deploy
any slide on its 737 airplanes.
NTSB also found that FAA allows American Airlines to include
inadvertent and emergency evacuation deployments toward the
accomplishment of its maintenance program; therefore, it is possible
that American would not purposely deploy any slides or slide rafts on
an A300 to comply with the deployment requirement during any given
year. In addition, NTSB found that FAA also allows Delta Air Lines to
include inadvertent and emergency evacuation deployments toward the
accomplishment of its maintenance program.
NTSB holds that because inadvertent and emergency deployments do not
occur in a controlled environment, problems with, or failures in, the
system may be more difficult to identify and record, and personnel
qualified to detect such failures may not be present. For example, in
an inadvertent or emergency slide or slide raft deployment,
observations on the amount of time it takes to inflate the slide or
slide raft, and the pressure level of the slide or slide raft are not
likely to be documented. For these reasons, a 1999 NTSB report said
that FAA's allowing these practices could potentially leave out
significant details about the interaction of the slide or slide raft
with the door or how well the crew follows its training mock-up
procedures. Accordingly, in 1999, NTSB recommended that FAA stop
allowing air carriers to count inadvertent and emergency deployments
toward meeting their maintenance program requirement because conditions
are not controlled and important information (on, for example, the
interface between the airplane and the evacuation slide system, timing,
durability, and stability) is not collected. The recommendation
continues to be open at the NTSB. NTSB officials said they would be
meeting to discuss this recommendation with FAA in the near future.
Additionally, NTSB recommended that FAA, for a 12-month period, require
that all operators of transport-category aircraft demonstrate the on-
airplane operation of all emergency evacuation systems (including the
door-opening assist mechanisms and slide or slide raft deployment) on
10 percent of each type of airplane (at least one airplane per type) in
their fleets. NTSB said that these demonstrations should be conducted
on an airplane in a controlled environment so that qualified personnel
can properly evaluate the entire evacuation system. NTSB indicated that
the results of the demonstrations (including an explanation of the
reasons for any failures) should be documented for each component of
the system and should be reported to FAA.[Footnote 76]
Overwing Exit Doors:
:
Background:
Prompted by a tragedy in which 57 of the 137 people on board a British
Airtours B-737 were killed because passengers found exit doors
difficult to access and operate, the British Civil Aviation Authority
initiated a research program to explore changes to the design of the
overwing exit (Type III) door.
Trained crewmembers are expected to operate most of the emergency
equipment on an airplane, including most floor-level exit doors. But
overwing exit doors, termed "self-help exits," are expected to be and
will primarily be opened by passengers without formal
training.[Footnote 77] NTSB reported that even when flight attendants
are responsible for opening the overwing exit doors, passengers are
likely to make the first attempt to open the overwing exit hatches
because the flight attendants are not physically located near the
overwing exits.
There are now two basic types of overwing exit doors--the "self-help"
doors that are manually removed inward and then stowed and the newer
"swing out" doors that open outward on a hinge.
According to NTSB, passengers continue to have problems removing the
inward-opening exit door and stowing it properly. The manner in which
the overwing exit is opened and how and where the hatch should be
stowed is not intuitively obvious to passengers, nor is it easily or
consistently depicted graphically. NTSB recently recommended to FAA
that Type III overwing exits on newly manufactured aircraft be easy and
intuitive to
open and have automatic stowage out of the egress path.[Footnote 78]
NTSB has indicated that the semiautomatic, fast-opening, Type III
overwing exit hatch could give passengers additional evacuation time.
Status:
Over-wing exit doors that "swing out" on hinges rather than requiring
manual removal are currently available. The European Joint Aviation
Authorities (JAA) has approved the installation of these outward-
opening hinged doors on new-production aircraft in Europe. In addition,
Boeing has redesigned the overwing exit door for its next-generation
737 series. This redesigned, hinged door has pressurized springs so
that it essentially pops up and outward, out of the way, once its lever
is pulled. The exit door handle was also redesigned and tested to
ensure that anyone could operate the door using either single or double
handgrips. Approximately 200 people who were unfamiliar with the new
design and had never operated an overwing exit tested the outward-
opening exit door. These tests found that the average adult could
operate the door in an emergency. The design eliminates the problem of
where to stow the exit hatch because the door moves up and out of the
egress route.
While the new swing-out doors are available, it will take some time for
them to be widely used. Because of structural difficulties and cost,
the new doors are not being considered for the existing fleet. For new-
production airplanes, their use is mixed because JAA requires them in
Europe for some newer Boeing 737s, but FAA does not require them in the
United States. However, FAA will allow their use. As a result, some
airlines are including the new doors on their new aircraft, while
others are not. For example, Southwest Airlines has the new doors on
its Boeing 737s. The extent to which other airlines and aircraft models
will have the new doors installed remains to be seen and will likely
depend on the cost of installation, the European market for the
aircraft, and any additional costs to train flight attendants in its
use.
Next Generation Evacuation Equipment and Procedures:
:
Background:
Airbus, a leading aircraft manufacturer, has begun building a family of
A380 aircraft, also called Large Transport Aircraft (see fig. 16).
Early versions of the A380, which is scheduled to begin flight tests in
2005 and enter commercial service in 2006, will have 482 to 524 seats.
The A380-800 standard layout references 555 seats. Later larger
configurations could accommodate up to 850 passengers. The A380 is
designed to have 16 emergency doors and require 16 escape slides,
compared with the 747, which requires 12. Later models of the A380
could have 18 emergency exits and escape slides.
Figure 16: Airbus' Planned Double Deck Aircraft:
[See PDF for image]
[End of figure]
Status:
The advent of this type of Large Transport Aircraft is raising
questions about how passengers will exit the aircraft in an emergency.
The upper deck doorsill of the A380 will be approximately 30 feet above
the ground, depending on the position (attitude) of the aircraft.
According to an Airbus official responsible for exit slide design and
operations, evacuation slides have to reach the ground at a safe angle
even if the aircraft is tipped up; however, extra slide length is
undesirable if the sill height is normal. Previously, regulations would
have required slides only to touch the ground in the tip-up case, even
if that meant introduction of relatively steep sliding surfaces.
However, because of the sill height, passengers may hesitate before
jumping and their hesitation may extend the total evacuation time.
Because some passengers may be reluctant to leap onto the slide when
they can see how far it is to the ground, the design concept of the
A380 evacuation slides includes blinder walls at the exit and a curve
in the slide to mask the distance to the ground.
A next-generation evacuation system developed by Airbus and Goodrich
called the "intelligent slide" is a possible solution to the problem of
the Large Transport Aircraft's slide length. The technology is not a
part of the slide, but is connected to the slide through what is called
a door management system composed of sensors. The "brains" of the
technology will be located inside the forward exit door of the cabin,
and the technology is designed to adjust the length of the slide
according to the fuselage's tipping angle to the ground. The longest
upper-deck slide for an A380 could exceed 50 feet.
The A380 slides are made of a nylon-based fabric that is coated with
urethane or neoprene, and they are 10 percent lighter than most other
slides on the market. They have to be packed tightly into small bundles
at the foot of emergency exit doors and are required to be fully
inflated in 6 seconds. Officials at Airbus noted that the slides are
designed to withstand the radiant heat of a postimpact fire for 180
seconds, compared with the 90 seconds required by regulators.
According to a Goodrich official, FAA will require Goodrich to conduct
between 2,000 and 2,500 tests on the A380 slides to make sure they can
accommodate a large number of passengers quickly and withstand wind,
rain, and other weather conditions. The upper-level slides, which are
wide enough for two people, have to enable the evacuation of 140 people
per minute, according to Airbus officials. An issue to be resolved is
whether a full-scale demonstration test will be required or whether a
partial test using a certain number of passengers, supplemented by a
computer simulation of an evacuation of 555 passengers, can effectively
demonstrate an evacuation from this type of aircraft. Airbus officials
told us that a full-scale demonstration could result in undesirable
injuries to the participants and is therefore not the preferred choice.
Officials at the Association of Flight Attendants have expressed
concern that there has not been a full-scale evacuation demonstration
involving the A380. They are concerned that computer modeling might not
really match the human experience of jumping onto a slide from that
height. In addition, they are concerned that other systems involved in
emergency exiting, such as the communication systems, need to be tested
under controlled conditions. As a result, they believe a full-scale
demonstration under the current 90-second standard is necessary.
Personal Flotation Devices:
:
Background:
All commercial aircraft that fly over water more than 50 nautical miles
from the nearest shore are required to be equipped with flotation
devices for each occupant of the airplane. According to FAA, 44 of the
50 busiest U.S. airports are located within 5 miles of a significant
body of water. In addition, life vests, seat cushions, life rafts, and
exit slides may be used as flotation devices for water emergencies.
FAA policies dictate that if personal flotation devices are installed
beneath the passenger seats of an aircraft, the devices must be easily
retrievable. Determinations of compliance with this requirement are
based on the judgment of FAA as the certifying authority.
Status:
FAA is conducting research and testing on the location and types of
flotation devices used in aircraft. When it has completed this work, it
is likely to provide additional guidance to ensure that the devices are
easily retrievable and usable. FAA's research is designed to analyze
human performance factors, such as how much time passengers need to
retrieve their vests, whether and how the cabin environment physically
interferes with their efforts, and how physically capable passengers
are of reaching their vests while seated and belted. FAA is reviewing
four different life vest installation methods and has conducted tests
on 137 human subjects. According to an early analysis of the data,
certain physical installation features significantly affect both the
ability of a typical passenger to retrieve an underseat life vest and
the ease of retrieval. This work may lead to additonal guidance on the
location of personal flotation devices.
FAA's research may also indicate a need for additional guidance on the
use of personal flotation devices. In a 1998 report on ditching
aircraft and water survival, FAA found that airlines differed in their
instructions to passengers on how to use personal flotation
devices.[Footnote 79] For example, some airlines advise that passengers
hold the cushions in front of their bodies, rest their chins on the
cushions, wrap their arms around the cushions with their hands grasping
the outside loops, and float vertically in the water. Other airlines
suggest that passengers lie forward on the cushions, grasp and hold the
loops beneath them, and float horizontally. FAA also reported that
airlines' flight attendant training programs differed in their
instructions on how to don life vests and when to inflate them.
[End of section]
Appendix VII: Summaries of General Cabin Occupant Safety and Health
Advancements:
This appendix presents information on the background and status of
potential advancements in general cabin occupant safety and health that
we identified, including the following:
* advanced warnings of turbulence;
* preparations for in-flight medical emergencies;
* reductions in health risks to passengers with certain medical
conditions, including deep vein thrombosis; and:
* improved awareness of radiation exposure.
This appendix also discusses occupational safety and health standards
for the flight attendant workforce.
Advanced Warnings of Turbulence:
:
Background:
According to FAA, the leading cause of in-flight injuries for cabin
occupants is turbulence. In June 1995, following two serious events
involving turbulence, FAA issued a public advisory to airlines urging
the use of seat belts at all times when passengers are seated, but
concluded that the existing rules did not require strengthening. In May
2000, FAA instituted a public awareness campaign, called Turbulence
Happens, to stress the importance of wearing safety belts to the flying
public.
Because of the potential for injury from unexpected turbulence, ongoing
research is attempting to find ways to better identify areas of
turbulence so that pilots can take corrective action to avoid it. In
addition, FAA's July 2003 draft strategic plan targets a 33 percent
reduction in the number of turbulence injuries to cabin occupants by
2008--from an annual average of 15 injuries per year for fiscal years
2000 through 2002 to no more than 10 injuries per year.
Status:
FAA is currently evaluating new airborne weather radar and other
technologies to improve the timeliness of warnings to passengers and
flight attendants about impending turbulence. For example, the
Turbulence Product Development Team, within FAA's Aviation Weather
Research Program, has developed a system to measure turbulence and
downlink the information in real time from commercial air carriers. The
International Civil Aviation Organization has approved this system as
an international standard. Ongoing research includes (1) detecting
turbulence in flight and reporting its intensity to augment pilots'
reports, (2) detecting turbulence remotely from the ground or in the
air using radar, (3) detecting turbulence remotely using LIDAR[Footnote
80] or the Global Positioning System's constellation of satellites, and
(4) forecasting the likelihood of turbulence over the continental
United States during the next 12 hours. Prototypes of the in-flight
detection system have been installed on 100 737-300s operated by United
Airlines, and two other domestic air carriers have expressed an
interest in using the prototype. FAA also plans to improve (1) training
on standard operating procedures to reduce injuries from turbulence,
(2) the dissemination of pilots' reports of turbulence, and (3) the
timeliness of weather forecasts to identify turbulent areas.
Furthermore, FAA encourages and some airlines require passengers to
keep their seatbelts fastened when seated to help avoid injuries from
unexpected turbulence.
Currently, pilots rely primarily on other pilots to report when and
where (e.g., specific altitudes and routes) they have encountered
turbulent conditions en route to their destinations; however, these
reports do not accurately identify the location, time, and intensity of
the turbulence. Further research and testing will be required to
develop technology to accurately identify turbulence and to make the
technology affordable to the airlines, which would ultimately bear the
cost of upgrading their aircraft fleets.
Preparations for In-flight Medical Emergencies:
:
Background:
The Aviation Medical Assistance Act of 1998 directed FAA to determine
whether the current minimum requirements for air carriers' emergency
medical equipment and crewmember emergency medical training should be
modified. In accordance with the act, FAA collected data for a year on
in-flight deaths and near deaths and concluded that enhancements to
medical kits and a requirement for airlines to carry automatic external
defibrillators were warranted. Specifically, the agency found that
these improvements would allow cabin crewmembers to deal with a broader
range of in-flight emergencies.
Status:
On April 12, 2001, FAA issued a final rule requiring air carriers to
equip their aircraft with enhanced emergency medical kits and automatic
external defibrillators by May 12, 2004. Most U.S. airlines have
installed this equipment in advance of the deadline.
In the future, new larger aircraft may require additional improvements
to meet passengers' medical needs. For example, new large transport
aircraft, such as the Airbus A-380, will have the capacity to carry
about 555 people on long-distance flights. Some aviation safety experts
are concerned that with the large number of passengers on these
aircraft, the number of in-flight medical emergencies will increase and
additional precautions for in-flight medical emergencies (e.g.,
dedicating an area for passengers who experience medical emergencies in
flight) should be considered. Airbus has proposed a medical room in the
cabin of its A-380 as an option for its customers.
Reducing Health Risks to Passengers with Certain Medical Conditions:
:
Background:
Passengers with certain medical conditions (e.g., heart and lung
diseases) can be at higher risk of health-related complications from
air travel than the general population. For example, passengers who
have limited heart or lung function or have recently had surgery or a
leg injury can be at greater risk of developing a condition known as
deep vein thrombosis (DVT) or travelers' thrombosis, in which blood
clots can develop in the deep veins of the legs from extended periods
of inactivity. Air travel has not been linked definitively to the
development of DVT, but remaining seated for extended periods of time,
whether in one's home or on a long-distance flight, can cause blood to
pool in the legs and increase the chances of developing DVT. In a small
percentage of cases, the clots can break free and travel to the lungs,
with fatal results.
In addition, the reduced levels of oxygen available to passengers in-
flight can have detrimental health effects on passengers with heart,
circulatory, and respiratory disorders because lower levels of oxygen
in the air produce lower levels of oxygen in the body--a condition
known as hypoxia. Furthermore, changes in cabin pressure (primarily
when the aircraft ascends and descends) can negatively affect ear,
nose, and throat conditions and pose problems for those flying after
certain types of surgery (e.g., abdominal, cardiac, and eye surgery).
Status:
Information on the potential effects of air travel on passengers with
certain medical conditions is available; however, additional research,
such as on the potential relationship between DVT and air travel, is
ongoing. The National Research Council, in a 2001 report on airliner
cabin air quality, recommended, among other things, that FAA increase
efforts to provide information on health issues related to air travel
to crewmembers, passengers, and health professionals. According to
FAA's Federal Air Surgeon, since this recommendation was received, the
agency has redoubled its efforts to make information and
recommendations on air travel and medical issues available through its
Web site [Hyperlink, www.cami.jccbi.gov/aam-400/PassengerHandS.htm]
www.cami.jccbi.gov/aam-400/PassengerHandS.htm. This site also includes
links to the Web sites of other organizations with safety and health
information for air travelers, such as the Aerospace Medical
Association, the American Family Physician (Medical Advice for
Commercial Air Travelers), and the Sinus Care Center (Ears, Altitude,
and Airplane Travel), and videos on safety and health issues for pilots
and air travelers. The Aerospace Medical Association's Web site,
[Hyperlink, http://www.asma.org/publication.html] http://www.asma.org/
publication.html, includes guidance for physicians to use in advising
passengers about the potential risks of flying based on their medical
conditions, as well as information for passengers to use in determining
whether air travel is advisable given their medical conditions.
Furthermore, some airlines currently encourage passengers to do
exercises while seated, to get up and walk around during long flights,
or to do both to improve blood circulation; however, walking around the
airplane can also put passengers at risk of injuries from unexpected
turbulence. In addition, a prototype of a seat has been designed with
imbedded sensors, which record the movement of a passenger and send
this information to the cabin crew for monitoring. The crew would then
be able to track passengers seated for a long time and could suggest
that these passengers exercise in their seats or walk in the cabin
aisles to enhance circulation.
While FAA's Web site on passenger and pilot safety and health provides
links to related Web sites and videos (e.g., cabin occupant safety and
health issues), historically, the agency has not tracked who uses its
Web site or how frequently it is used to monitor the traveling public's
awareness and use of this site. Agency officials told us that they plan
to install a counter capability on its Civil Aerospace Medical
Institute Web site by the end of August 2003 to track the number of
visits to its aircrew and passenger health and safety Web site. The
World Health Organization has initiated a study to help determine if a
linkage exists between DVT and air travel. Further, FAA developed a
brochure on DVT that has been distributed to aviation medical examiners
and cited in the Federal Air Surgeon's Bulletin. The brochure is aimed
at passengers rather than airlines and suggests exercises that can be
done to promote circulation.
Improved Awareness of Radiation Exposure:
:
Background:
Pilots, flight attendants, and passengers who fly frequently are
exposed to cosmic radiation at higher levels (on a cumulative basis)
than the average airline passenger and the general public living at or
near sea level. This is because they routinely fly at high altitudes,
which places them closer to outer space, which is the primary source of
this radiation. High levels of radiation have been linked to an
increased risk of cancer and potential harm to fetuses. The amount of
radiation that flight attendants and frequent fliers are exposed to--
referred to as the dose--depends on four primary factors: (1) the
amount of time spent in flight; (2) the latitude of the flight--
exposure increases at higher latitudes; for example, at the same
altitude, radiation levels at the poles are about twice those at the
equator; (3) the altitude of the flight--exposure is greater at high
altitudes because the layer of protective atmosphere becomes thinner;
and (4) solar activity--exposure is higher when solar activity
increases, as it does every 11 years or so. Peak periods of solar
activity, which can increase exposure to radiation by 10 to 20 times,
are sometimes called solar storms or solar flares.
Status:
FAA's Web site currently makes available guidance on radiation exposure
levels and risks for flight and cabin crewmembers, as well as a system
for calculating radiation doses from flying specific routes and
specific altitudes. To increase crewmembers' awareness of in-flight
radiation exposure, FAA issued two Advisory Circulars for crewmembers.
The first Advisory Circular, issued in 1990, provided information on
(1) cosmic radiation and air shipments of radioactive material as
sources of radiation exposure during air travel; (2) guidelines for
exposure to radiation; (3) estimates of the amounts of radiation
received on air carriers' flights on various routes to and from, or
within, the contiguous United States; and (4) examples of calculations
for estimating health risks from exposure to radiation. The second
Advisory Circular, issued in 1994, recommended training for crewmembers
to inform them about in-flight radiation exposure and known associated
health risks and to assist them in making informed decisions about
their work on commercial air carriers. The circular provided a possible
outline of courses, but left it to air carriers to gather the subject
matter materials. To facilitate the monitoring of radiation exposure
levels by airliner crewmembers and the public (e.g., frequent fliers),
FAA has developed a computer model, which is publicly available via the
agency's Web site. This Web site also provides guidance and
recommendations on limiting radiation exposure. However, it is unclear
to what extent flight attendants, flight crews, and frequent fliers are
aware of and use FAA's Web site to track the radiation exposure levels
they accrue from flying. Agency officials told us that they plan to
install a counter capability its Civil Aerospace Medical Institute Web
site by the end of August 2003, to track the number of visits to its
aircrew and passenger health and safety Web site. FAA also plans to
issue an Advisory Circular by early next year, which incorporates the
findings of a just completed FAA report, "What Aircrews Should Know
About Their Occupational Exposure to Ionizing Radiation." This Advisory
Circular will include recommended actions for aircrew and information
on solar flare event notification of aircrew. While FAA provides
guidance and recommendations on limiting the levels of cosmic radiation
that flight attendants and pilots are exposed to, it has not developed
any regulations.
In contrast, the European Union issued a directive for workers in May
1996, including air carrier crewmembers (cabin and flight crews) and
the general public, on basic safety and health protections against
dangers arising from ionizing radiation. This directive set dose limits
and required air carriers to (1) assess and monitor the exposure of all
crewmembers to avoid exceeding exposure limits, (2) work with those
individuals at risk of high exposure levels to adjust their work or
flight schedules to reduce those levels, and (3) inform crewmembers of
the health risks that their work involves from exposure to radiation.
It also required airlines to work with female crewmembers, when they
announce a pregnancy, to avoid exposing the fetus to harmful levels of
radiation. This directive was binding for all European Union member
states and became effective in May 2000. According to European safety
officials, pregnant crewmembers are often given the option of an
alternative job with the airline on the ground to avoid radiation
exposure to their fetuses. Furthermore, when flight attendants and
pilots reach recommended exposure limits, European air carriers work
with crewmembers to limits or change their subsequent flights and
destinations to minimize exposure levels for the balance of the year.
Some air carriers ground crewmembers when they reach annual exposure
limits or change their subsequent flights and destinations to minimize
exposure levels for the balance of the year.
Occupational Safety and Health Standards for Flight Attendants:
:
Background:
In 1975, FAA assumed responsibility from the Occupational Health and
Safety Administration (OSHA) for establishing safety and health
standards for flight attendants. However, FAA has only recently begun
to take action to provide this workforce with OSHA-like protections.
For example, in August 2000, FAA and OSHA entered into a memorandum of
understanding and issued a joint report in December 2000, which
identified safety and health concerns for the flight attendant
workforce and the extent to which OSHA-type standards could be used
without compromising aviation safety. On September 29, 2001, the DOT
Office of the Inspector General (DOT IG) reported that FAA had made
little progress toward providing flight attendants with workplace
protections and urged FAA to address the recommendations in the
December 2000 report and move forward with setting safety and health
standards for the flight attendant workforce. In April 2002, the DOT IG
reported that FAA and OSHA had made no progress since it issued its
report in September 2001. According to FAA officials, the joint FAA and
OSHA effort was put on hold because of other priorities that arose in
response to the events of September 11, 2001.
Status:
FAA has not yet established occupational safety and health standards to
protect the flight attendant workforce. FAA is conducting research and
collecting data on flight attendants' injuries and illnesses.
On March 4, 2003, FAA announced the creation of a voluntary program for
air carriers, called the Aviation Safety and Health Partnership
Program. Through this program, the agency intends to enter into
partnership agreements with participating air carriers, which will, at
a minimum, make data on their employees' injuries and illnesses
available to FAA for collection and analysis. FAA will then establish
an Aviation Safety and Health Program Aviation Rule-Making Committee to
provide advice and recommendations to:
* develop the scope and core elements of the partnership program
agreement;
* review and analyze the data on employees' injuries and illnesses;
* identify the scope and extent of systematic trends in employees'
injuries and illnesses;
* recommend remedies to FAA that use all current FAA protocols,
including rule-making activities if warranted, to abate hazards to
employees; and:
* create any other advisory and oversight functions that FAA deems
necessary.
FAA plans to select members to provide a balance of viewpoints,
interests, and expertise. The program preserves FAA's complete and
exclusive responsibility for determining whether proposed abatements of
safety and health hazards would compromise or negatively affect
aviation safety.
FAA is also funding research through the National Institute for
Occupational Safety and Health (NIOSH) to, among other things,
determine the effects of flying on the reproductive health of flight
attendants, much of:
which has been completed.[Footnote 81] FAA plans to monitor cabin air
quality on a selected number of flights, which will help it set
standards for the flight attendant workforce.
The Association of Flight Attendants has collected a large body of data
on flight attendants' injuries and illnesses, which it considers
sufficient for use in establishing safety and health standards for its
workforce. Officials from the association do not believe that FAA needs
to collect additional data before starting the standard-setting
process.
The European Union has occupational safety and health standards in
place to protect flight attendants, including standards for monitoring
their levels of radiation exposure. An official from an international
association of flight attendants told us that while flight attendants
in Europe have concerns similar to those of flight attendants in the
United States (e.g., concerns about air quality in airliner cabins),
the European Union places a heavier emphasis on worker safety and
health, including safety and health protections for flight attendants.
[End of section]
Appendix VIII: Application of a Cost Analysis Methodology to Inflatable
Lap Belts:
The following illustrates how a cost analysis might be conducted on
each of the potential advancements discussed in this report. Costs
estimated through this analysis could then be weighed against the
potential lives saved and injuries avoided from implementing the
advancements. This methodology would allow advancements to be compared
using comparable cost data that when combined with similar analyses of
effectiveness to help decisionmakers determine which advancements would
be most effective in saving lives and avoiding injuries, taking into
account their costs. The methodology provides for developing a cost
estimate despite significant uncertainties by making use of historical
data (e.g, historical variations in fuel prices) and best engineering
judgments (e.g., how much weight an advancement will add and how much
it will cost to install, operate, and maintain). The methodology
formally takes into account the major sources of uncertainty and from
that information develops a range of cost estimates, including a most
likely cost estimate. Through a common approach for analyzing costs,
the methodology facilitates the development of comparable estimates.
This methodology can be applied to advancements in various stages of
development.
Inflatable Lap Belts:
Inflatable lap belts are designed to protect passengers from a fatal
impact with the interior of the airplane, the most common cause of
death in survivable accidents. Inflatable seat belts adapt advanced
automobile technology to airplane seats in the form of seat belts with
air bags embedded in them. Several hundred of these seatbelt airbags
have been installed in commercial airliners in bulkhead rows.
Summary of Results:
We calculated that requiring these belts on an average-sized airplane
in the U.S. passenger fleet would be likely to cost from $98,000 to
$198,000 and to average about $140,000 over the life of the airplane.
On an annual basis, the cost would be likely to range from $8,000 to
$17,000 and to average $12,000.
We considered several factors to explain this range of possible costs.
The installation price of these belts is subject to uncertainty because
of their limited production to date. In addition, these belts add
weight to an aircraft, resulting in additional fuel costs. Fuel costs
depend on the price of jet fuel and on how many hours the average
airplane operates, both subject to uncertainty. Table 5 lists the
results of our cost analysis for an average-sized airplane in the U.S.
fleet.
Table 4: Costs to Equip an Average-sized Airplane in the U.S. Fleet
with Inflatable Lap Seat Belts, Estimated under Alternative Scenarios
(In 2002 discounted dollars):
Cost: Life-cycle; Cost scenario: Low: $98,000; Cost scenario:
Average: $140,000; Cost scenario: High: $198,000; Cost scenario: 95
percentile[A]: $186,000.
Cost: Annualized; Cost scenario: Low: $8,000; Cost scenario:
Average: $12,000; Cost scenario: High: $17,000; Cost scenario: 95
percentile[A]: $16,000.
Cost: Per ticket[B]; Cost scenario: Low: $0.08; Cost scenario:
Average: $0.13; Cost scenario: High: $0.19; Cost scenario: 95
percentile[A]: $0.18.
Source: GAO analysis.
[A] For example, a 95 percentile estimate means that there is a 95
percent probability that the total life-cycle costs per airplane will
be $186,000 or less.
[B] Cost rounded to the nearest cent.
[End of table]
According to our analysis, the life-cycle and annualized cost estimates
in table 5 are influenced most by variations in jet fuel prices,
followed by the average number of hours flown per year and the
installation price of the belts. The cost per ticket is influenced most
by variations in jet fuel prices, followed by the average number of
hours flown per year, the number of aircraft in the U.S. fleet, and the
number of passenger tickets issued.
Methodology:
To analyze the cost of inflatable lap belts, we collected data on key
cost variables from a variety of sources. Information on the belts'
installation price, annual maintenance and refurbishment costs, and
added weight was obtained from belt manufacturers. Historical
information on jet fuel prices, extra gallons of jet fuel consumed by a
heavier airplane, average hours flown per year, average number of seats
per airplane, number of airplanes in the U.S. fleet, and number of
passenger tickets issued per year was obtained from FAA and DOT's
Office of Aviation Statistics.
To account for variation in the values of these cost variables, we
performed a Monte Carlo simulation.[Footnote 82] In this simulation,
values were randomly drawn 10,000 times from probability distributions
characterizing possible values for the number of seat belts per
airplane, seat belt installation price, jet fuel price, number of
passenger tickets, number of airplanes, and hours flown.[Footnote 83]
This simulation resulted in forecasts of the life-cycle cost per
airplane, the annualized cost per airplane, and the cost per ticket.
Major assumptions in the cost analysis are described by probability
distributions selected for these cost variables. For jet fuel prices,
average number of hours flown per year, and average number of seats per
airplane, historical data were matched against possible probability
distributions.[Footnote 84] Mathematical tests were performed to find
the best fit between each probability distribution and the data set's
distribution. For the installation price, number of passenger tickets,
and number of airplanes, less information was available.[Footnote 85]
For these variables, we selected probability distributions that are
widely used by researchers. Table 6 lists the type of probability
distribution and the relevant parameters of each distribution for the
cost variables.
Table 5: Key Assumptions:
Cost variable: Fuel price; Type of distribution: lognormal; Mean or
average: $0.93; Standard deviation: $0.33.
Cost variable: Seats; Type of distribution: lognormal; Mean or average:
161; Standard deviation: 8.
Cost variable: Installation price; Minimum: $300;
Maximum: $600; Likeliest: $450.
Cost variable: Hours; Type of distribution: extreme value; Mean or
average: 2,353; Mode: 2,643; Scale: 539.
Cost variable: Airplanes; Type of distribution: normal; Mean or
average: 4,438; Standard deviation: 399.
Cost variable: Tickets; Type of distribution: normal; Mean or average:
419; Standard deviation: 35.
Source: GAO analysis.
[End of table]
[End of section]
Appendix IX: GAO Contacts and Staff Acknowledgments:
GAO Contacts:
Gerald L. Dillingham (202) 512-2834 Glen Trochelman (202) 512-2834
Beverly Norwood (202) 512-2834:
Staff Acknowledgments:
In addition to those named above, Chuck Bausell, Helen Chung, Elizabeth
Eisenstadt, David Ehrlich, Bert Japikse, Sarah Lynch, Sara Ann
Moessbauer, and Anthony Patterson made key contributions to this
report.
(540017):
FOOTNOTES
[1] Large, or 'transport category' commercial aircraft are defined as
those with a capacity of 30 or more passengers or a load of 7,500
pounds or more.
[2] In identifying 28 advancements, we are not suggesting that these
are the only advancements being pursued, rather that these advancements
have been recognized by aviation safety experts we contacted as
offering promise for improving the safety and health of cabin
occupants.
[3] A separate rule-making effort in 1988 required that newly
manufactured aircraft be equipped with stronger, 16g seats; however, it
did not require that the existing U.S. fleet of commercial aircraft be
retrofitted with these seats.
[4] FAA officials told us that using photo-luminescent lighting is a
different way to meet an existing standard and, therefore, should not
be considered an advancement in safety. However, because photo-
luminescent floor lighting differs from standard floor lighting in that
it works without electricity, some in the aviation community consider
it a safety advancement.
[5] NTSB, Survivability of Accidents Involving Part 121 U.S. Air
Carrier Operations, 1983 Through 2000, NTSB/SR-01/01.
[6] FAA subsequently proposed, in October 2002, that the 16g seats be
put into the entire existing fleet for both passengers and flight
attendants within 14 years to better protect passengers from impact
forces. We included this proposal in our list of advancements.
[7] Affected aircraft included Boeing MD-80, MD-88, MD-90, DC-10, and
MD-11.
[8] According to FAA, Boeing is flight testing a system similar to the
FAA design, and Airbus is flight testing the FAA system in an A320.
Boeing announced that it would begin installing inerting systems
similar to the FAA design in their 747s in 2005.
[9] As noted, actions taken to improve cabin air quality will be
discussed in another report.
[10] ATA noted that, for those technologies that are ready, FAA must
develop design and certification standards before undertaking the rule-
making process to require their implementation.
[11] U.S. General Accounting Office, Aviation Rule-making: Further
Reform Is Needed to Address Long-standing Problems, GAO-01-821
(Washington, D.C.: July 9, 2001).
[12] Under Executive Order 12866, federal agencies and the Office of
Management and Budget (OMB) categorize proposed and final rules in
terms of their potential impact on the economy and the industry
affected. The Order defines a regulatory action as "significant" if it,
among other things, has an annual impact on the economy of $100 million
or more and adversely affects the economy in a material way. To measure
the overall impact of the 1998-rule-making reforms, through discussions
with FAA officials, we created a database of 76 significant rules.
These rules constituted the majority (about 83 percent) of FAA's
significant rule workload from fiscal year 1995 through fiscal year
2000.
[13] According to ATA, even if a technology is available in the
marketplace, it may not be adopted by the airlines until it has been
certified by FAA--ensuring that "improvements" do not inadvertently
compromise overall safety of the aircraft.
[14] One of these U.S. carriers is no longer in bankruptcy.
[15] A Monte Carlo simulation is a widely used computational method for
generating probability distributions of variables that depend on other
variables or parameters represented as probability distributions.
[16] The Headquarters Division of Transport Canada provides guidance
and assistance to Regional Civil Aviation Safety Inspectors -
Occupational Health and Safety who conduct inspections, investigations,
and promotional visits to ensure that airline operators are committed
to the safety and health of their employees.
[17] The European Union, previously known as the European Community, is
an institutional framework for the construction of a united Europe. The
European Commission is a governing body that proposes policies and
legislation.
[18] JAA currently has 26 full members and 11 candidate members.
[19] According to officials from the United Kingdom's Civil Aviation
Authority, a JAA member, a limited benefit analysis has been developed
to provide guidance, but this document has not yet been published.
[20] On July 15, 2002, the European Parliament and the Council of the
European Union (E.U.) adopted Regulation (EC) No 1592/2002 establishing
common rules for the E.U. in the field of civil aviation and
establishing a new European Aviation Safety Agency.
[21] Officials with the United Kingdom's Civil Aviation Authority
commented that inflatable airbags are but one solution for providing
upper torso restraint. These officials cited a European Union funded
"Going Safe" seat, which through an energy-absorbing device enables a
lap and diagonal belt system to be fitted to an unmodified seat rail.
[22] R.G.W. Cherry & Associates, Analysis of Structural Factors
Influencing the Survivability of Occupants in Aeroplane Accidents,
Civil Aviation Authority, Paper 96011 (London: December 1996).
[23] The 1988 seat dynamic performance standards changed seat standards
and testing. The new standards expanded seat testing to include
potential injuries caused by head strikes on the back of seats and on
stationary bulkheads, as well as criteria limiting lumbar and femur
loads. These limits, if exceeded, could cause injuries that could
prevent evacuation. Seats must be tested for forces in several
directions to account for forward, downward, and other directional
movements such as may occur in an accident. Previous FAA regulations
required seats to be tested in only one primary direction at 9gs of
force. The 16g level was adopted rather than a higher standard because
the floor tracks of many of the airplanes in use in 1988 would break
away upon an impact of more than 16gs.
[24] The initial proposed rule, Retrofit of Improved Seats in Air
Carrier Transport-Category Airplanes, 53 Fed. Reg. 17650 (1988)
proposed requiring compliance with improved crashworthiness standards
for all seats of transport-category airplanes used under part 121 and
part 135 and prohibiting the operation of these airplanes unless all
seats met the crashworthiness performance standards required by
Improved Seat Safety Standards, 53 Fed. Reg. 17640 (1988).
[25] In general, most 16g-compatible seats meet the structural
requirements of the 16g seat rule but do not need to meet the head
injury criteria.
[26] Each aircraft type typically has 8 to 10 different types of seats,
each of which must be certified; a typical economy class seat costs
about $1,800. For marketing reasons, airlines usually choose their own
distinctive seats, which must be certified for each type of airplane
they fly.
[27] According to a Boeing Official, one cost estimate compiled by ATA
and the Aerospace Industries Association in response to NPRM 88-8
presented in December 1988 showed the recurring per program cost [was
listed] at $440,000.
[28] R.G.W. Cherry & Associates, Benefit Analysis for Aircraft 16-g
Dynamic Seats, DOT/FAA/AR-00/13 (Washington, D.C.: April 2000). This
study examined 25 large commercial airplane accidents that occurred
from 1984 and through 1998 and possibly involved seat-related
fatalities or injuries.
[29] In commenting on the proposed 16g seat retrofit rule, Boeing noted
that there were fundamental, fatal flaws in both the analysis of
benefits and the analysis of costs of implementing this rule.
[30] Until recently, FAA generally did not require a manufacturer to
meet new, higher safety standards that are put in place after the date
the manufacturer applies for a type certificate unless FAA can
demonstrate that an unsafe condition exists. FAA's changed product rule
requires manufacturers to comply with the latest airworthiness
standards when significant design changes are proposed for a derivative
aircraft that will be certificated under an amended or supplemental
type certificate. 65 Fed. Reg. 36244 (2002).
[31] Improved Seats in Air Carrier Transport Category Airplanes, 67
Fed. Reg. 62294 (2002).
[32] FAA assumed benefits of $3 million for an averted fatality and
$0.5 million for an averted serious injury.
[33] A study of survivable accidents that took place from 1970 through
1978 indicated that floor deformation during a crash was a primary
cause of seat failure in 60 percent of the accidents. (Chandler, et
al., DOT/FAA/CT-82-118)
[34] In the dynamic 16g seat test with a deformed floor, one floor
track must be pitched 10 degrees (up or down) relative to the other
floor track, which must in turn be rolled 10 degrees.
[35] Some 16g-compatible seats were manufactured to meet 16g dynamic
testing standards but did not complete FAA's certification process for
floor deformation on representative floors and seat tracks and
technically met only the 9g seat certification requirements.
[36] Report on the accident to Boeing 737-400 G-OBME near Kegworth,
Leicestershire, on 8 January 1989, Aircraft Accident Report 4/90, AAIB,
DOT, London, HMSO; "Recommendations for Injury Prevention in Transport
Aviation Accidents," prepared for NASA, Langley Research Center, by
Simula Technologies, Inc., February 2, 2000, TR-99112, S97324.
[37] "Benefit Analysis for Aircraft 16-g Dynamic Seats," Final Report,
U.S. Department of Transportation (DOT/FAA/AR-00/13) and U.K Civil
Aviation Authority (CAA Paper 99003).
[38] R.G.W. Cherry & Associates, Analysis of Structural Factors
Influencing the Survivability of Occupants in Aeroplane Accidents,
Civil Aviation Authority, Paper 96011 (London: December 1996).
[39] Flight Safety Foundation, "Increased Amount and Types of Carry-On
Baggage Bring New Industry Responses," November-December 1997, Vol. 32,
No. 6, p. 6.
[40] Bins are required to withstand 9g forward (longitudinal), 3g
upward, 6g downward, and other load requirements.
[41] One manufacturer's testing shows that the inflatable lap belts can
reduce head injury criteria scores from about 2,000 to 200-300 in a 16g
impact. A score of 1,000 implies a skull fracture, possible loss of
consciousness, and a 16 percent risk of life-threatening brain injury.
[42] At an annual life-cycle cost of approximately $12,000 to outfit an
average airliner with lap belt air bags on all seats of the U.S. fleet,
assuming an installation cost of $450 per seat position not including
maintenance and replacement costs. A GAO analysis of the 2002 Annual
Report of Southwest Airlines, which has relatively low passenger
revenue per available seat mile compared with other airlines, found
that each seat produced an annual net revenue of about $10,000. See
appendix VIII for our analysis of the costs associated with lap belts.
[43] According to the manufacturer, the installation of the most common
design requires maintenance of one minute per seat position for a
diagnostic test every 1,900 flight hours, and the devices must be
refurbished about once every 7 years at about a third of the initial
price.
[44] ATA noted that more than 80 fuel tank Airworthiness Directives
have been adopted since the crash of TWA Flight 800 and that a similar
number of directives are currently under development.
[45] The committee also estimated, on the basis of data on nitrogen
exposure from the Occupational Safety and Health Administration and the
National Institute of Occupational Safety and Health, that from 24 to
81 lives could be lost over the same period, depending on the degree of
oxygen depletion. The report did not specifically indicate whether this
forecast was for a ground-based, onboard, hybrid, or any other inerting
system.
[46] By using more general terminology, this terminology excludes
hybrid and liquid nitrogen inerting systems, also considered by the
Aviation Rule-making Advisory Committees for their 1998 and 2001
reports.
[47] According to an FAA safety expert, FAA is addressing only the
center wing tank because of its significantly higher flammability
exposure and the low risk of an explosion in the wing tanks.
[48] A current controversial issue is whether inerting technology will
be considered flight-critical hardware--and therefore will be required
to function properly for the aircraft to fly. If it is deemed flight
critical, its reliability may affect the dispatch rate of the aircraft.
For example, if the technology experiences operational problems, the
aircraft may be allowed to fly only 25 times a week, even if it is
scheduled to fly 30 times a week. This problem reduces revenue to the
airline and is a greater concern for civilian than for military
aviation, because there are usually replacements for military aircraft.
[49] FAA fuel tank safety experts conducted tests under high
temperatures and found that a tank with an oxygen level of 12 percent
was inert against internal threats, such as sparks and hot surfaces.
According to one FAA expert, the system provides a "below 12 percent"
inert tank under all conditions except for a brief time during descent
when local pockets in the tank may approach 16 percent oxygen. The
expert said that at this time, the tank is generally cool enough to be
nonflammable even with normal air (21 percent oxygen) in the tank. If
the tank is cool enough, internal threats will not ignite the fuel air
mixture. He said the probability of explosions is very low in the wing
tanks because they are not heated by other airplane systems.
[50] These estimates included the costs for modifying aircraft that are
currently in service, in production, and being designed, and they
assumed a predicted reduction in the accident rate of 75 percent.
[51] This system does not have the capability to inert the cargo
compartment, bay, and wheel well, and it dumps oxygen as effluent
rather than using it for an emergency passenger oxygen system.
[52] A 2001 NASA study indicated that two liquid nitrogen systems were
the only ones that appeared capable of inerting all fuel tanks of a
commercial aircraft full time.
[53] One type of smart sensor would analyze the light-scattering
properties of the particles in the air to differentiate between smoke
particles and nuisance sources.
[54] Aircraft Cargo Compartment Smoke Detector Alarm Incidents on U.S.-
Registered Aircraft, 1974-1999, DOT/FAA/AR-TN00/29 (Washington, D.C.:
June 2000). The study indicated a generally increasing number of false
alarms as the size of the fleet grew.
[55] Operating requirements for all aircraft have been amended by a
2000 final rule, whose deadline was recently extended for the third
time, to report the occurrence or detection of failures, malfunctions,
or defects concerning fire warning systems and false warnings of fire
or smoke in the entire U.S. fleet.
[56] According to FAA fire safety experts, most of these are
contaminated air or smoke events in the cabin, detected by people, not
by detectors.
[57] This recommendation was one of several resulting from the Canadian
Transportation Safety Board's investigation of the Swissair Flight 111
crash.
[58] A use is considered "critical" when a need exists to protect
against fire or explosion risks in areas that would result in a serious
threat to essential services or pose an unacceptable threat to life,
the environment, or national security. Typical critical users are
aerospace, certain petrochemical production processors, certain marine
applications, and national defense.
[59] Flashover can occur in an airplane cabin fire when all exposed
combustible surfaces reach ignition temperature more or less
simultaneously. It is characterized by rapid increases in temperature,
with smoke, toxic gases, and oxygen depletion creating a largely
nonsurvivable environment.
[60] R.G.W. Cherry & Associates, Analysis of Structural Factors
Influencing the Survivability of Occupants in Aeroplane Accidents,
Civil Aviation Authority, Paper 96011 (London: December 1996).
[61] Increasing the Survival Rate in Aircraft Accidents: Impact
Protection, Fire Survivability, and Evacuation, European Transport
Safety Council (December 1996).
[62] Twin-fluid systems use air, nitrogen, or another gas in
combination with water. They require lower water supply pressure and
bigger nozzle orifices.
[63] Inerting involves reducing flammability in fuel tanks, which is
discussed separately in this report.
[64] Boeing commented that this more recent system would not pass the
original cargo minimum performance standard, and Boeing disagrees with
FAA's relaxing of the original standard.
[65] An average widebody aircraft carries 50,000 gallons of aviation
fuel at takeoff.
[66] Fuels function by releasing combustible gases. Indicators of
volatility include a fuel's boiling point (the higher the boiling
point, the less volatile the fuel) and vapor pressure (the higher the
vapor pressure, the more volatile the fuel). Therefore, raising the
temperature can increase volatility. A highly volatile fuel is more
likely to form a flammable or explosive mixture with air than a
nonvolatile fuel. By definition, gases are volatile. Liquid fuels
either are sufficiently volatile at room temperature to produce
combustible vapor (ethanol, petrol) or they produce sufficient
combustible vapors when heated (kerosene).
[67] The fuel vaporization rate is the minimum temperature to which the
pure liquid fuel must be heated so that the vapor pressure is high
enough for an explosive mixture to be formed with air--then the liquid
is allowed to evaporate and is brought into contact with a flame,
spark, or hot filament. Flash points are lower than ignition
temperatures.
[68] A surfactant, or surface-active agent, is a soluble compound that
reduces the surface tension of liquids, or reduces interfacial tension
between two liquids or a liquid and a solid. A gelling agent is a fuel
"thickener."
[69] FAA's benefit estimate, based on $2.7 million per life saved,
ranges from $37.7 million to $231.5 million, discounted to present
value, based partially on 37.2 deaths avoided from its 2000 study. FAA
could not quantify benefits from flame propagation requirements, but
indicated that avoiding an accident with 169 passenger fatalities would
avert a $231.5 million loss (not including the cost of the plane).
[70] Improved Flammability Standards for Thermal/Acoustic Insulation
Materials Used in Transport Category Airplanes; Final Rule, FAA/DOT (14
C.F.R. parts 25, 91, et al.).
[71] These methods test the heat release rate, total heat of combustion
of the volatiles, thermal stability, char yield, decomposition process,
and rate of decomposition.
[72] This manual is designed to provide the aviation community with
basic flight information and air traffic control procedures for use in
the National Airspace System of the United States.
[73] NTSB, Safety Study: Emergency Evacuation of Commercial Airlines,
[A-00-86] (Washington, D.C.: 2001).
[74] These estimates assume 100 percent smoke hood use. The net 97
lives saved with a 15 second delay assumes that smoke hoods would have
saved lives in six accidents and cost lives in four; the net 145 lives
saved with a 10 percent reduction in the evacuation rate assumes that
smoke hoods would have saved lives in six accidents and cost lives in
two.
[75] "Smoke Hoods: Net Safety Benefit Analysis," a collaborative effort
by the Civil Aviation Authority, Federal Aviation Administration,
Direction Générale de l'Aviation Civile, and Transport Canada, London,
November 1987, CAA Paper 87017.
[76] NTSB, Emergency Evacuation of Commercial Airplanes, 2001, [A-00-
76] (Washington, D.C.:2000).
[77] The overwing exit hatch can weigh as much as 65 pounds and be 20
inches wide and 36 inches high.
[78] NTSB, Emergency Evacuation of Commercial Airplanes, [A-00-76]
(Washington, D.C., 2000).
[79] LB & M Associates, Inc., and Garnet A. McLean, Analysis of
Ditching and Water Survival Training Programs of Major Airframe
Manufacturers and Airlines, CAMI [DOT/FAA/AM-98/19], (Washington,
D.C.).
[80] LIDAR (LIght Detection And Ranging) is a technology that can
measure the distance, speed, rotation, and chemical composition and
concentration of a remote target, such as turbulence.
[81] NIOSH is also conducting research on airliner cabin environmental
quality, respiratory symptoms of flight attendants, and disease
transmission.
[82] "Monte Carlo simulation is a widely used computational method for
generating probability distributions of variables that depend on other
variables or parameters represented as probability distributions. Monte
Carlo methods are to be contrasted with the deterministic methods used
to generate specific single number or point estimates." Susan Poulter,
"Monte Carlo Simulation in Environmental Risk Assessment - Science,
Policy And Legal Issues," 9 Risk: Health, Safety & Environment 7
[Winter 1998].
[83] A probability distribution is a set of all possible events and
their associated probabilities. Probability refers to the likelihood of
an event.
[84] Historical data from 1975 through 2001 were available for the
number of seats per plane, and from 1977 through 2002 for jet fuel
prices. Aircraft utilization data for 2001 were available for annual
hours per aircraft.
[85] Historical data from 1995 through 2001 were available for the
number of planes and tickets.
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