Commercial Aviation
Impact of Airline Crew Scheduling on Delays and Cancellations of Commercial Flights
Gao ID: GAO-08-1041R September 17, 2008
Media coverage of airline service problems, combined with congressional hearings on these problems, has put flight delays and cancellations in the spotlight. Department of Transportation (DOT) data show that flight delays and cancellations have generally increased over the last decade. Since 1998, the number of flight delays and cancellations has increased 62 percent nationwide, while the number of scheduled flight operations has increased about 38 percent. Also, a May 2008 report by the Joint Economic Committee found that, collectively, passengers were delayed 320 million hours in 2007. The report also estimated that domestic flight delays last year cost the U.S. economy as much as $41 billion and raised airlines' operating costs by $19 billion. In 2007, airlines reported to DOT that 73 percent of flights were on time, while 24 percent were delayed and 2 percent were canceled. Of those flights that were delayed, airlines reported the majority of flight delays were caused by 3 categories of delays: a previous aircraft arriving late; the national aviation system--a category of delays that encompasses a broad set of circumstances, such as congestion or bad weather; and air carrier--a category of 42 potential causes of delay that includes, but is not limited to, problems associated with how the airline schedules its flight crews. With demand pushing more flights into an already congested airspace, one delayed or canceled flight can create ripples in the system, causing other flights to be delayed or canceled. In such an environment, the effective scheduling of available flight crews is key to better ensuring the on-time performance of flights. Congress asked that we assess commercial airline policies and practices for crew scheduling. Accordingly, this report addresses the following questions: (1) How do airlines schedule flight crews? (2) To what extent, if any, does crew scheduling contribute to flight delays and cancellations? (3) What steps do stakeholders report might reduce delays and cancellations due to crew scheduling?
Airlines use computerized optimization models to schedule flight crews while adhering to federal regulations and contractual agreements. As a fundamental safety tenet, all airlines are subject to Federal Aviation Regulations that establish maximum crew flight times and minimum rest requirements. In addition, airlines must adhere to conditions in their collective bargaining agreements, which they negotiate with the labor organizations representing their employees. Labor is generally one of an airline's largest costs, along with fuel. Consequently, airlines use computerized models to schedule crews in a manner that helps to minimize these costs, while adhering to the Federal Aviation Regulation limitations and to collective bargaining agreement conditions. Flight delays and cancellations caused by crew scheduling alone appear to be rare and frequently arise from other problems. Detailed data provided by 6 of the airlines indicated that, in 2007, delays due to crew scheduling accounted for no more than about 3 percent of any airline's flights, and that cancellations due to crew scheduling were less than one-quarter of 1 percent of all flights for any airline. Most other stakeholders similarly indicated that crew scheduling is not a major contributor to delays and cancellations. Airlines and other stakeholders identified other problems as being more significant causes of flight delays and cancellations, including aircraft maintenance and problems with the national airspace system, such as congestion or bad weather. Additionally, airlines reported that delays and cancellations due to crew scheduling are often the result of other delays, which can create a "ripple effect" when crews and aircraft needed for subsequent flights are not available on time. Stakeholders identified several ongoing and potential actions that airlines and the government could take to reduce delays and cancellations attributable to crew scheduling. Airlines have taken several steps to reduce the potential for delays and cancellations due to crew scheduling, including adding time to flight schedules to account for delays, using reserve crews, positioning crews in anticipation of expected weather, and scheduling crews to stay with the same aircraft between flights. Additionally, several of the airlines reported taking steps to avoid delays in the New York area--a region known for airspace congestion--such as not scheduling crews on often-delayed flights scheduled to leave New York at later times in the day, and avoiding scheduling connecting flights out of New York to an airline's hub airport. Stakeholders also suggested a number of steps that the federal government could take, including modernizing the air traffic control system; improving East Coast operations, particularly in the New York region; and revising the Federal Aviation Regulations pertaining to duty and rest hours. Finally, in July 2008, the federal government began a test program designed to evaluate expedited access to secure areas of airports for properly credentialed commercial flight crew members, which could reduce the time that flight crew members spend in security screening lines.
GAO-08-1041R, Commercial Aviation: Impact of Airline Crew Scheduling on Delays and Cancellations of Commercial Flights
This is the accessible text file for GAO report number GAO-08-1041R
entitled 'Commercial Aviation: Impact of Airline Crew Scheduling on
Delays and Cancellations of Commercial Flights' which was released on
September 17, 2008.
This text file was formatted by the U.S. Government Accountability
Office (GAO) to be accessible to users with visual impairments, as part
of a longer term project to improve GAO products' accessibility. Every
attempt has been made to maintain the structural and data integrity of
the original printed product. Accessibility features, such as text
descriptions of tables, consecutively numbered footnotes placed at the
end of the file, and the text of agency comment letters, are provided
but may not exactly duplicate the presentation or format of the printed
version. The portable document format (PDF) file is an exact electronic
replica of the printed version. We welcome your feedback. Please E-mail
your comments regarding the contents or accessibility features of this
document to Webmaster@gao.gov.
This is a work of the U.S. government and is not subject to copyright
protection in the United States. It may be reproduced and distributed
in its entirety without further permission from GAO. Because this work
may contain copyrighted images or other material, permission from the
copyright holder may be necessary if you wish to reproduce this
material separately.
GAO-08-1041R:
United States Government Accountability Office:
Washington, DC 20548:
September 17, 2008:
The Honorable Ted Stevens:
United States Senate:
Subject: Commercial Aviation: Impact of Airline Crew Scheduling on
Delays and Cancellations of Commercial Flights:
Dear Senator Stevens:
Media coverage of airline service problems, combined with congressional
hearings on these problems, has put flight delays and cancellations in
the spotlight. Department of Transportation (DOT) data show that flight
delays and cancellations have generally increased over the last decade.
Since 1998, the number of flight delays and cancellations has increased
62 percent nationwide, while the number of scheduled flight operations
[Footnote 1] has increased about 38 percent. Also, a May 2008 report by
the Joint Economic Committee found that, collectively, passengers were
delayed 320 million hours in 2007. The report also estimated that
domestic flight delays last year cost the U.S. economy as much as $41
billion and raised airlines' operating costs by $19 billion.[Footnote 2]
In 2007, airlines reported to DOT that 73 percent of flights were on
time, while 24 percent were delayed and 2 percent were canceled.
[Footnote 3],[Footnote 4] Of those flights that were delayed, airlines
reported the majority of flight delays were caused by 3 categories of
delays: a previous aircraft arriving late; the national aviation
system--a category of delays that encompasses a broad set of
circumstances, such as congestion or bad weather; and air carrier--a
category of 42 potential causes of delay that includes, but is not
limited to, problems associated with how the airline schedules its
flight crews.[Footnote 5] With demand pushing more flights into an
already congested airspace, one delayed or canceled flight can create
ripples in the system, causing other flights to be delayed or canceled.
In such an environment, the effective scheduling of available flight
crews is key to better ensuring the on-time performance of flights.
You asked that we assess commercial airline policies and practices for
crew scheduling. Accordingly, this report addresses the following
questions: (1) How do airlines schedule flight crews? (2) To what
extent, if any, does crew scheduling contribute to flight delays and
cancellations? (3) What steps do stakeholders report might reduce
delays and cancellations due to crew scheduling?
To respond to these objectives, we reviewed scheduling practices and
related information about flight delays and cancellations. We requested
interviews with the 12 largest domestic airlines, as measured by
passenger volume in 2007. We conducted semistructured interviews, and
gathered and analyzed data from 11 of these airlines as well as data
from DOT.[Footnote 6] Data on crew-scheduling-related delays and
cancellations are not publicly reported, and we were not able to
independently verify the accuracy of these data. However, we asked
airlines about steps they take to verify the accuracy and reliability
of their data and corroborated the findings arising from these data
with aviation stakeholders and academic experts. In addition, the data
from the airlines may not be comparable due to internal differences in
how they gather these data. We also interviewed officials from the
Federal Aviation Administration (FAA) and other stakeholders, including
professional associations representing airlines and crew members,
academics, and an airline passenger consumer advocacy group. (See enc.
I for additional information on our scope and methodology.)
We conducted this performance audit from March 2008 to September 2008
in accordance with generally accepted government auditing standards.
Those standards require that we plan and perform the audit to obtain
sufficient, appropriate evidence to provide a reasonable basis for our
findings and conclusions based on our audit objectives. We believe that
the evidence obtained provides a reasonable basis for our findings and
conclusions based on our audit objectives.
Results in Brief:
Airlines use computerized optimization models to schedule flight crews
while adhering to federal regulations and contractual agreements. As a
fundamental safety tenet, all airlines are subject to Federal Aviation
Regulations that establish maximum crew flight times and minimum rest
requirements.[Footnote 7] For example, a commercial pilot can fly a
maximum of 8 hours during a duty period (or workday).[Footnote 8] In
addition, airlines must adhere to conditions in their collective
bargaining agreements, which they negotiate with the labor
organizations representing their employees. The collective bargaining
agreements often address the crews' work conditions; nonunionized
airlines often have company policies that address similar work
conditions. Labor is generally one of an airline's largest costs, along
with fuel. Consequently, airlines use computerized models to schedule
crews in a manner that helps to minimize these costs, while adhering to
the Federal Aviation Regulation limitations and to collective
bargaining agreement conditions.
Flight delays and cancellations caused by crew scheduling alone appear
to be rare and frequently arise from other problems. According to the
11 airlines with whom we spoke, flight delays and cancellations
attributed to crew scheduling are minimal. Detailed data provided by 6
of the airlines indicated that, in 2007, delays due to crew scheduling
accounted for no more than about 3 percent of any airline's flights,
and that cancellations due to crew scheduling were less than one-
quarter of 1 percent of all flights for any airline. Most other
stakeholders similarly indicated that crew scheduling is not a major
contributor to delays and cancellations. Airlines and other
stakeholders identified other problems as being more significant causes
of flight delays and cancellations, including aircraft maintenance and
problems with the national airspace system, such as congestion or bad
weather. Additionally, airlines reported that delays and cancellations
due to crew scheduling are often the result of other delays, which can
create a "ripple effect" when crews and aircraft needed for subsequent
flights are not available on time. For example, if an incoming flight
arrives at an airport late and the aircraft and its crew are scheduled
for two separate subsequent flights, then the first delay can cause two
additional flights to be delayed.
Stakeholders identified several ongoing and potential actions that
airlines and the government could take to reduce delays and
cancellations attributable to crew scheduling. Airlines have taken
several steps to reduce the potential for delays and cancellations due
to crew scheduling, including adding time to flight schedules to
account for delays, using reserve crews, positioning crews in
anticipation of expected weather, and scheduling crews to stay with the
same aircraft between flights. Additionally, several of the airlines
reported taking steps to avoid delays in the New York area--a region
known for airspace congestion--such as not scheduling crews on often-
delayed flights scheduled to leave New York at later times in the day,
and avoiding scheduling connecting flights out of New York to an
airline's hub airport. Stakeholders also suggested a number of steps
that the federal government could take, including modernizing the air
traffic control system; improving East Coast operations, particularly
in the New York region; and revising the Federal Aviation Regulations
pertaining to duty and rest hours. Finally, in July 2008, the federal
government began a test program designed to evaluate expedited access
to secure areas of airports for properly credentialed commercial flight
crew members, which could reduce the time that flight crew members
spend in security screening lines.
Background:
Since June 2003, DOT has required domestic airlines with at least 1
percent of the industry's annual revenue to report the reasons that
flights are delayed or canceled using the following five broad
categories:
Late-arriving aircraft means that a previous flight using the same
aircraft arrived late, thereby causing the subsequent flight to depart
late. This category comprises delays (not cancellations) and does not
provide the original source of delay for the late-arriving aircraft,
such as a delay in the national aviation system.
National aviation system delays and cancellations refer to a broad set
of circumstances attributable to the national airspace system, such as
airport operations, heavy traffic volume, and air traffic control. This
category also includes any nonextreme weather condition that slows the
operation of the system, such as wind or fog, but does not prevent
flying.
Air carrier includes 42 potential causes of delay and cancellation that
are within the control of the airlines, such as maintenance, awaiting
the arrival of connecting passengers, baggage loading, and crew issues.
Extreme weather delays and cancellations occur when serious weather
conditions prevent the operation of an aircraft. Examples of this kind
of weather include tornadoes, snowstorms, and hurricanes.[Footnote 9]
Security includes evacuation of an airport, reboarding due to a
security breach, and long lines at the passenger screening areas.
Airlines reported to DOT that the majority of delays during 2007 were
attributed to the late-arriving aircraft, national aviation system, and
air carrier categories. As illustrated in figure 1, delays reported
under the air carrier category accounted for nearly 29 percent of
flight delays last year, just below the 33 percent of delays attributed
to the national aviation system and about 34 percent of delays
attributed to late-arriving aircraft.[Footnote 10]
Figure 1: Causes of Flight Delays, 2007:
[Refer to PDF for image]
This figure is a pie-chart depicting the following data:
Causes of Flight Delays, 2007:
Late arriving aircraft: 33.7%;
National aviation system: 33.2%;
Air carrier: 28.9%;
Extreme weather: 4.0%;
Security: 0.3%.
Note: Total may not add up to 100 percent due to rounding. Percentages
are based on the number of flight operations reported under each
category.
Source: DOT.
[End of figure]
In July 2008, we reported that the data collected by DOT on the sources
of delays provide information about where delays occurred and what
caused the delay, but that these data are incomplete.[Footnote 11]
Specifically, the DOT-reported categories are too broad to provide
meaningful information on the root causes of delays. For example,
delays attributed to the airlines could consist of various causes, such
as a late crew, aircraft maintenance, or baggage loading, but these
more specific causes are not captured in DOT data. In addition, the
largest source of systemwide delays--late-arriving aircraft, which
represents about 34 percent of delayed flights (see fig. 1)--masks the
original source of delay. For example, the original source of delay for
a late-arriving aircraft could be because of the air carrier, security,
extreme weather, or the national aviation system--or a combination of
one or more of these sources.
Airlines Schedule Flight Crews Using Optimization Models While Adhering
to Federal Regulations and Contractual Agreements:
Crew scheduling is part of a larger airline scheduling process.
Airlines we interviewed reported a similar scheduling process that goes
through chronological phases (see fig. 2).
Figure 2: Airline Scheduling Process:
[Refer to PDF for image]
This figure is an illustration of the airline scheduling process, as
follows:
Schedule design;
Fleet assignment;
Crew scheduling.
Source: GAO.
[End of figure]
First, the marketing department of the airline designs a schedule by
determining the flights to be flown and departure times during a given
time period, such as a month. Subsequent planning decisions are based
on this schedule. Second, the airline assigns the aircraft to each
flight to maximize revenues and minimize costs. The type of aircraft
assigned determines the qualifications and quantity of crew needed. The
final step--crew scheduling--assigns crews (pilots, and flight
engineers, if needed, in the cockpit and flight attendants in the
cabin) to the aircraft.
Airlines use computerized optimization models to develop crew schedules
and allow flight crews to bid on the schedules. Labor is generally one
of an airline's largest costs, along with fuel. Consequently, airlines
use computerized models to schedule crews in a manner that helps to
minimize these costs. Five of the 11 airlines we interviewed use a
preferential bidding system (PBS) to produce monthly crew assignments
based on crew member preferences. PBS incorporates a crew member's
preplanned activities, such as vacations, training, medical
appointments, and military leave, when developing the crew member's
schedule for the month. Four airlines reported using a "bid line"
system, while the remaining 2 airlines reported using a bid line system
as well as a PBS. In bid line systems, the airline develops monthly
schedules and crew members bid to work those schedules. This system
does not take into account conflicts that may arise with preplanned
activities, such as vacations, training, medical appointments, and
military leave. As such, conflicts may arise, and those conflicting
trips must then be assigned to other crew members. Regardless of the
approach selected, the airline will have schedule-holding crews and
reserve crews. Schedule-holding crews have a known schedule of flights
for the month. In contrast, reserve crews do not have a schedule of
flights, but are "on call" to fly during certain days throughout the
month when the airline needs crew members for particular flights.
As they develop crew schedules, airlines must adhere to federal
regulations and collective bargaining agreements (CBA). All 11 airlines
we interviewed cited Federal Aviation Regulation (FAR) requirements as
the primary constraint in building a crew schedule. As a fundamental
safety tenet, all airlines are subject to FAR flight time limitations
and rest requirements and must work within these primary constraints
when designing schedules.[Footnote 12] The current FAR limits a
commercial pilot's flight time to 8 hours in a duty period, 100 hours
in a calendar month, and 1,000 hours in a calendar year, with certain
exceptions.[Footnote 13] The FARs also specify the minimum number of
hours of rest that pilots must have between duty periods.[Footnote 14]
Furthermore, pilots can only fly those aircraft types for which they
are qualified.[Footnote 15] Each airline must also consider the crews'
work conditions, which are established in its CBA, or in its company
policies if the airline is nonunionized and does not have a CBA. For
example, the airlines we interviewed reported that these requirements
cover monthly flight time; time between flights; and any leave,
training, vacation requests, or trip preference requests. The airlines
reported monthly flying hours from a low of 60 to 63 hours a month to a
high of 90 to 92 hours a month. Stakeholders noted that the closer
pilots are scheduled to the FARs' monthly maximum of 100 hours, the
greater the reduction in scheduling flexibility. This limits the
airlines' use of pilots to make schedule adjustments when there is a
delay from a major disruption, because pilots would no longer have room
in their schedules for additional hours. However, all of the airlines
we interviewed have reserve crews that can fly during these disruptions
to help get the airline get back on schedule.
Delays and Cancellations Caused by Crew Scheduling Appear Rare and
Frequently Stem from Other Problems:
According to the airlines, most aviation industry associations, and
academic experts we interviewed, crew scheduling is not a major source
of flight delays and cancellations. Stakeholders pointed to other
problems as being more significant causes of delays and cancellations,
including aircraft maintenance and problems with the national airspace
system, such as congestion or bad weather. Additionally, airlines
reported that delays and cancellations due to crew scheduling are often
the result of other delays, which can create a "ripple effect" when
crews and aircraft scheduled for subsequent flights are not available
on time.
Stakeholders Report That Crew Scheduling Is Responsible for Few Delays
and Cancellations:
According to officials at the 11 airlines we interviewed, crew
scheduling causes few flight delays and cancellations.[Footnote 16] Six
airlines provided detailed information on flight delays and
cancellations. This detailed information showed that for each of these
airlines in 2007, crew scheduling caused delays for less than about 3
percent of flights and cancellations for less than one-quarter of 1
percent of flights. The other 5 airlines we interviewed did not provide
detailed data, but officials for those airlines also stated that crew
scheduling causes few delays and cancellations. Two of these airlines
told us that, on the basis of their data, about 5 to 6 percent of
delays and/or cancellations were due to crew scheduling, while 2 other
airlines estimated that crew scheduling accounted for less than 10
percent of delays within the air carrier category.
Among the other factors within the airlines' control, airlines reported
that aircraft maintenance and time needed to board passengers are
greater causes of delay than problems with crew scheduling. DOT data
show that air carrier delays accounted for about 7 percent of flights
in 2007.[Footnote 17] The percentages of flights delayed due to air
carrier causes were about the same for the 11 airlines we interviewed,
affecting about 6 percent of flights in 2007. According to the DOT
data, cancellations due to the air carrier represented about 1 percent
of all U.S. carrier flights in 2007;[Footnote 18] among the 11 airlines
we interviewed, cancellations due to the air carrier were slightly less
than 1 percent of flights in 2007.
Most other stakeholders we interviewed, including academic experts and
almost all aviation industry associations, shared the view that crew
scheduling was not a major cause of flight delays and cancellations.
Like the airlines, these stakeholders identified other causes as being
more prominent in this area, such as problems with the national
airspace system related to congestion or weather. Conversely, one
aviation industry association characterized crew-scheduling problems as
common and often leading to delays and cancellations, although this
association also indicated that other issues are more prevalent causes
of air carrier delay, such as maintenance and problems with the
national airspace system.
Airlines Report That Crew-Scheduling Delays Are Often the Result of
Other Delays in the National Airspace System:
According to the airlines, when delays associated with crew scheduling
do occur, they are frequently the result of other types of delays in
the national airspace system, such as those caused by congestion or bad
weather. As we have previously mentioned, crew scheduling is a complex
process that puts crews in position to serve flights. In some
instances, crew scheduling can respond to problems, but other problems
will disrupt the airlines' crew schedules. A ripple effect may occur
when delayed or canceled flights create problems for subsequent flights
because the crew or equipment for those flights is delayed or out of
position. This problem can propagate further delays when the crew and
plane from a delayed or canceled flight are needed for separate
subsequent flights but are not available on time. When such crew-
related delays are linked to previous flights where the aircraft
arrived late, then the underlying cause of delay may not be known. The
following text and figures 3 through 5 illustrate various delay
scenarios and their potential causes and results:
Scenario 1: Crew Arrives Late:
In the scenario depicted in figure 3, the crew arrives late for its
first flight, which causes a delay. This delay is reported to DOT as an
air carrier delay, since it is considered within the control of the
airline. According to the airlines, this scenario is relatively rare,
although they reported some isolated instances of such crew-related
problems, such as crews calling in sick during labor disputes or crews
being out of position because of schedule disruptions caused by severe
weather. This type of delay could also arise if crews arrive late the
previous day and have to extend their rest time to comply with federal
requirements for pilot rest, as we have previously discussed. Airlines
reported having varying percentages of crew members who commute from
outside the area where they are based, with estimates ranging from 19
to 55 percent, although these percentages vary greatly by city.
Although commuting problems for crews that live outside the area where
they are based can contribute to this type of delay, airlines and the
aviation industry associations that represent pilots and flight
attendants told us that such problems were not a major issue, and
several airlines reported taking steps to lessen the potential for such
delays, such as getting crews in position early if they expect bad
weather to disrupt commuting.[Footnote 19]
Figure 3: Scenario 1 - Crew Arrives Late:
[Refer to PDF for image]
Illustration:
Flight is delayed because crew does not arrive for original report time
and departing aircraft i delayed more than 15 minutes;
Arrival at airport;
Recorded DOT flight delay: "Air Carrier" (crew scheduling).
Source: GAO.
[End of figure]
Scenario 2: Aircraft Arrives Late:
In the second scenario, depicted in figure 4, a previous flight (flight
#1) is delayed, which causes a later flight (flight #2) to be delayed;
the crew remains with the airplane for both flights. Since flight #2 is
delayed because flight #1 arrived late to the airport, the flight #2
delay would be attributed to late-arriving aircraft and not to the
reason that flight #1 was delayed. For example, if the flight #1 delay
was due to the air carrier, the flight #2 delay would not be attributed
to the air carrier, but would rather be reported as a delay due to late-
arriving aircraft. When airlines report flight delays due to late-
arriving aircraft, the underlying cause of the delay--whether it is the
air carrier, the national aviation system, or any other source--is not
reported. Some of the stakeholders we interviewed pointed out, and we
have previously reported, that the late-arriving aircraft delay
category effectively masks the underlying cause of delay.[Footnote 20]
While four airlines told us they could track the underlying cause of
delay, two other airlines said they do not track the underlying cause
of delay.
Figure 4: Scenario 2 - Aircraft Arrives Late:
[Refer to PDF for image]
Illustration:
Flight #1, Aircraft A, Crew A: Flight delay for any reason of more than
15 minutes causes departing aircraft to be delayed;
Arrival at airport;
Flight #2, Aircraft A, Crew A: Recorded DOT flight delay: :Late-
Arriving Aircraft."
Source: GAO.
[End of figure]
Scenario 3: Aircraft Arrives Late and Crew Changes Planes:
In the third scenario, depicted in figure 5, two flights are delayed
because a previous flight arrives late, potentially creating a ripple
effect. The aircraft (aircraft A) from flight #1 is scheduled to be
flown by a different crew (crew B) for flight #2. Therefore, flight #2
is delayed because the aircraft is not available, and the delay is
reported to DOT as being due to late-arriving aircraft. Additionally,
the crew (crew A) from flight #1 is scheduled to switch planes (from
aircraft A to aircraft B) and fly flight #3. Therefore, flight #3 is
also delayed, although this delay would be due to a late crew and
reported to DOT as an air carrier delay, regardless of the reason that
flight #1 was delayed. If, as a result of earlier delays, crew A could
not fly flight #3 because it would exceed their maximum allotted duty
time, the flight might be canceled if no reserve crew was available to
fly the aircraft. Depending on the severity of the delay, there is a
potential for these delayed flights to create additional downstream
delays, thereby propagating delays throughout the air travel system.
According to the airlines we interviewed, these types of delays and
cancellations--those caused by earlier problems--are the most frequent
reason for crew scheduling delays and cancellations.
Figure 5: Scenario 3 - Aircraft Arrives Late and Crew Changes Planes:
[Refer to PDF for image]
Illustration:
Flight #1: Flight delay for any reason of more than 15 minutes causes
departing aircraft to be delayed;
Arrival at airport;
Crew A transfers to Aircraft B, Crew B takes over operations of
Aircraft A;
Flight #2: Recorded DOT flight delay: Late-Arriving Aircraft."
Flight #3: Recorded DOT flight delay: "Air Carrier" (crew scheduling).
Source: GAO.
[End of figure]
Stakeholders Identified Several Ongoing and Potential Actions That
Airlines and the Government Could Take to Reduce Crew-Scheduling Delays
and Cancellations:
Airlines have taken several steps to reduce the potential for delays
and cancellations due to crew scheduling, including adding time to
flight schedules to account for delays, using reserve crews,
positioning crews in anticipation of expected weather, and scheduling
crews to stay with the same aircraft between flights. Additionally,
several of the airlines reported taking steps to avoid delays in the
New York region--a region known for airspace congestion--such as not
scheduling crews leaving New York for later flights and avoiding
scheduling connecting flights out of the New York region to an
airline's hub airport. Most stakeholders also reported that modernizing
the national airspace system would further reduce both crew-scheduling
delays, and flight delays and cancellations overall.
Airlines Have Implemented Several Methods to Reduce Crew-Scheduling
Delays and Cancellations in Problem Areas:
The 11 airlines with whom we spoke reported taking a number of common
actions to reduce delays and cancellations associated with crew
scheduling. These airlines track delays and cancellations to identify
patterns, underlying causes, and solutions to delays and cancellations.
The 11 airlines identified the following actions:
* Eight airlines reported that they added time in their schedules for
flights or connections, particularly in congested areas, to account for
expected delays. This added time creates a buffer, thereby reducing the
likelihood of a delay.
* Seven airlines reported using their reserve crews to fly during
schedule disruptions to help get the airline back on schedule. The
reserve crews take the place of the crew members delayed on a previous
flight, thereby helping to reduce a departure delay.
* Five airlines reported scheduling crews and aircraft together to
reduce delays associated with crews changing planes, such as when
making a connection at a congested hub (see fig. 5). In general,
however, airlines noted that since pilots are not allowed to fly as
many hours during a duty day as flight attendants or the aircraft,
limiting the schedules of flight attendants and aircraft to fly with
the same cockpit crew during the day would be inefficient and more
expensive.
Other actions that airlines reported included making last-minute
changes in crew schedules to use available crews for flights when
scheduled crews are delayed or otherwise unavailable, and getting crews
in position early if the airline expects poor weather.
Six airlines reported taking specific measures to address delays in the
New York region, which is known to be a major source of delays in the
United States.[Footnote 21] For example, one airline told us that crews
on flights originating in the New York region and other East Coast
airports, particularly later in the day, will not be scheduled to fly a
connecting flight, thereby reducing the potential for flight delays and
cancellations from these airports to cause later flights in the system
to be delayed, as depicted in figures 4 and 5. Another airline avoided
scheduling connecting flights from New York through its major hub.
Officials at one airline said they intentionally do not serve the New
York region, since doing so is known to cause operational problems. For
example, one airline reported over 60 percent of its delayed flights
were attributable to problems in the New York region, such as a lengthy
ground delay that could potentially disrupt the pilot's schedule if
such a delay might cause the pilot to exceed the daily limit on duty
time.
Stakeholders Identified Several Government Actions to Reduce Crew-
Scheduling-Related Delays and Cancellations:
The majority of the airlines, aviation industry associations, and
academic experts we interviewed stated that the national airspace
system was the major source of delays and cancellations, and many told
us that the federal government should take steps to improve the system.
These stakeholders attributed many crew-scheduling delays to a
precursor event in the system--such as a ground, weather, or air
traffic control delay--as opposed to a crew not getting to the airplane
for its first flight of the day. To help reduce crew-scheduling-related
and other delays and cancellations, the stakeholders suggested a number
of actions the federal government could take, which included
modernizing the national airspace system and improving East Coast
operations, particularly in the New York region. As we have previously
reported, FAA faces significant challenges in keeping the nation's
current airspace system running as efficiently as possible, given the
increasing demand for air travel.[Footnote 22] DOT and FAA were
implementing several actions that are intended to reduce flight delays
for the summer 2008 travel season, but these actions will likely have a
limited effect on reducing delays. Due to the high proportion of delays
at the three major New York area airports, many of these actions are
specifically designed to address congestion in the New York area. In
fact, one-third of aircraft in the national airspace system move
through the New York area at some point during a typical day, and
delays in this region can have a disproportionate impact on delays
experienced throughout the rest of the system. However, these ongoing
and planned initiatives are not intended to significantly boost
capacity, but rather to enhance efficiency and better manage delays.
[Footnote 23]
Most aviation experts believe the long-term solution to reducing delays
depends largely on expanding capacity through the Next Generation Air
Traffic Management System (NextGen)--a complicated effort to modernize
the air traffic control system by 2025. NextGen will use satellite-
based technologies and state-of-the-art procedures to handle the
increasing volume of air traffic, while further improving safety and
security. The transformation of the national airspace system is one of
the federal government's most complex undertakings. Although NextGen is
a collaborative effort, the bulk of the responsibility for successful
implementation and transition belongs to FAA. As we have reported, the
agency faces a number of management challenges as it begins
implementing NextGen systems and procedures.[Footnote 24] These
challenges include funding NextGen, hiring and retaining the right
skill set within FAA, developing a facility plan for NextGen, meeting
the research and development needs of NextGen, and establishing
credibility with stakeholders regarding the agency's NextGen efforts.
Another action the airlines suggested that the federal government could
take to add flexibility to the crew-scheduling process was to review
the federal regulations on pilot duty and rest requirements. The FARs
currently limit a pilot to 8 hours of flying during a duty period for
safety reasons. Five airlines we interviewed reported that the federal
aviation regulations regarding pilot duty time should be revised. For
example, one airline told us that it would be more efficient for them
and increase their scheduling flexibility if a pilot's schedule was
limited to 12 hours of duty time, rather than 8 hours of flight time,
which could allow a pilot to fly across the country and back within one
duty period. The Air Line Pilots Association (ALPA), an airline pilot
union, also supports overhauling current flight and duty time
regulations for commercial airline pilots, but for different reasons.
ALPA stated it is opposed to any flight time increase beyond 8 hours in
a duty day, citing concerns about current flight-crew-scheduling
practices. ALPA also stated that pilots are flying more hours and
working more days with longer duty hours since September 11, 2001, and
that this change, along with contract revisions resulting in pay
reductions, has already forced pilots to fly increased hours.
Finally, the federal government has recently begun a test program
designed to evaluate expedited access to secure areas of airports for
properly credentialed commercial flight deck crew members at three test
airports. The Transportation Security Administration launched a 60-day
test program in July 2008 called Crew Personnel Advanced Screening
System, or CrewPASS,[Footnote 25] which allows uniformed eligible
flight deck crew members to enter the secure area of these checkpoints
via the exit lane of the security checkpoint after presenting their
airline-issued identification and another form of identification to
transportation security officers (TSO). TSOs will check these
credentials via a secure, real-time flight deck crew member database
that includes a picture and other information to verify the
individual's identity. Flight deck crew members who use this program
are subject to random screening, observation by behavior detection
officers, and other layers of security. ALPA stated that it supports
this program because it should reduce the time that flight crew members
spend in security screening lines, among other reasons.
Concluding Observations:
While safety is paramount to the airlines, containing costs is a
fundamental goal for any industry. The airlines use computerized
optimization models to schedule crews in a manner that helps minimize
costs within the requirements of federal safety regulations, collective
bargaining agreements, and flight schedules. Flight delays cost the
airlines money. Therefore, it is in their best interest to avoid these
problems, where feasible, particularly if they stem from situations
within the control of the airlines, such as crew scheduling. As flight
delays and cancellations have become more pervasive, airlines have
taken steps to adjust their crew-scheduling practices to partially
address this problem, such as by building extra time into flight
schedules or keeping crews and aircraft together when flying in and out
of congested airports where scheduled aircraft or crew changes compound
delays. While such measures may help reduce problems with delays and
cancellations, they alone cannot solve this problem. The majority of
the stakeholders with whom we spoke told us that, in general, flight
delays and cancellations are mostly rooted in systemic problems with
the national airspace system. Ultimately, the necessary upgrades to the
national airspace system infrastructure will require a broad-based
effort on the part of government and nonfederal stakeholders. As we
have previously reported, the current approach to managing air
transportation is becoming increasingly inefficient and operationally
obsolete.
Agency Comments:
We requested comments from the Secretary of Transportation, the 11
airlines with whom we spoke, and the Air Line Pilots Association, but
none were provided.
We are sending copies of this report to the Senate Committee on
Science, Commerce, and Transportation, the House Committee on
Transportation and Infrastructure, other interested congressional
committees, the Secretary of Transportation, and the 11 airlines with
whom we spoke. We will make copies available to others upon request. In
addition, this report will be available at no cost on the GAO Web site
at [hyperlink, http://www.gao.gov].
Should you or your staff have any questions about this report, please
contact me at (202) 512-2834 or flemings@gao.gov. Contact points for
our Offices of Congressional Relations and Public Affairs may be found
on the last page of this report. Key contributors to this report were
Mike Clements (Assistant Director), Lauren Calhoun, Bess Eisenstadt,
Colin Fallon, Andrew Huddleston, Maren McAvoy, Sara Ann Moessbauer, and
Josh Ormond.
Sincerely yours,
Signed by:
Susan Fleming:
Director, Physical Infrastructure Issues:
Enclosure:
Enclosure I:
Scope and Methodology:
To respond to the objectives of this report, we reviewed scheduling
practices and related information about flight delays and
cancellations. We requested interviews with the 12 largest domestic
airlines as measured by passenger volume in 2007 reported by the
Department of Transportation (DOT).[Footnote 26] We conducted
semistructured interviews with 11 of these airlines, which included a
mix of legacy, low-cost, and regional airlines.[Footnote 27] We also
interviewed officials from the Federal Aviation Administration;
representatives of the Air Line Pilots Association, the Air Transport
Association, the Association of Flight Attendants, the Regional Airline
Association, and the Air Travelers Association; and academic experts
from George Mason University, the Massachusetts Institute of
Technology, and the University of Michigan.
To describe how airlines schedule crews and the policies and
requirements that this process follows, we reviewed relevant federal
regulations and collective bargaining agreements between airlines and
pilots available from the National Mediation Board. We also discussed
these policies and requirements with the airlines.
To evaluate the extent to which crew scheduling may contribute to
flight delays and cancellations, we reviewed available data from DOT
and gathered and analyzed data from the 11 airlines we interviewed. We
interviewed DOT about the accuracy and reliability of its data on
airlines' on-time performance, which include data on flight delays and
cancellations, and determined that these data were sufficiently
reliable for the purposes of this report. Additionally, the airlines
from which we received data assured us that their data were audited and
reviewed; therefore, we determined that these data were sufficiently
reliable for the purposes of this report. Data on crew-scheduling-
related delays and cancellations are not publicly reported, and we were
not able to independently verify their accuracy. However, we asked the
11 airlines that we interviewed about the steps they take to verify the
accuracy and reliability of their data. We also corroborated the
findings arising from these data with aviation stakeholders and
academic experts who confirmed that the magnitude of delays and
cancellations were consistent with the data provided by the 6 airlines.
In addition, the data from different airlines may not be comparable
because of differences in how the airlines gather these data. Finally,
these data are illustrative of recent delays and cancellations due to
crew scheduling at the 11 airlines we interviewed and do not
necessarily represent the entire industry.
We conducted our work from March 2008 to September 2008 in accordance
with generally accepted government auditing standards. Those standards
require that we plan and perform the study to obtain sufficient,
appropriate evidence to provide a reasonable basis for our findings and
conclusions based on our study objectives. We believe that the evidence
obtained provides a reasonable basis for our findings and conclusions
based on our audit objectives.
[End of section]
Footnotes:
[1] "Flight" means any nonstop scheduled passenger flight segment with
a specific flight number scheduled to be operated pursuant to a
published schedule within a specific origin-destination city pair,
other than transborder or foreign air transportation. See 14 C.F.R. §
234.2.
[2] Joint Economic Committee Majority Staff, Your Flight Has Been
Delayed Again: Flight Delays Cost Passengers, Airlines, and the U.S.
Economy Billions (Washington, D.C.: May 2008).
[3] Federal regulations require that domestic air carriers that account
for at least 1 percent of domestic scheduled passenger revenues submit
scheduled domestic flight performance data, including the cause of
delays and cancellations, to DOT. See 14 C.F.R. §§ 234.1-234.4. In
2007, 20 carriers, operating about 70 percent of all scheduled
departures and serving about 90 percent of all domestic passengers,
reported these data.
[4] Less than 1 percent of flights were diverted.
[5] Flight crews include the pilots and, in some cases, a flight
engineer in the cockpit (cockpit crew) and the flight attendants in the
cabin (cabin crew). In this report, "flight crew" pertains only to the
cockpit crew, unless otherwise specified. In addition, this report
references both the national aviation system--a formal category of DOT
data to which flight delays and cancellations are attributed--and the
national airspace system--the complex, interconnected, and
interdependent network of systems, procedures, facilities, aircraft,
and people that must work together to ensure safe and efficient
operations.
[6] We requested data from and interviewed officials representing
AirTran Airways, Alaska Airlines, American Airlines and American Eagle,
Continental Airlines, Delta Air Lines, JetBlue Airways, Northwest
Airlines, Southwest Airlines, United Airlines, and US Airways. SkyWest
Airlines did not respond to our request.
[7] 14 C.F.R. § 121.471.
[8] "Duty period" means the period of elapsed time between reporting
for an assignment involving flight time and release from that
assignment by the certificate holder conducting domestic, flag, or
supplemental operations. See 14 C.F.R. § 121.467.
[9] Weather delays are captured in several categories and, according to
DOT, a true picture of total weather-related delays requires several
steps. First, DOT combines the extreme weather category and the weather
delays from the national aviation system category. Second, DOT performs
a calculation to determine the weather-related delays included in the
late-arriving aircraft category. Airlines do not report the causes of
late-arriving aircraft, but DOT makes an allocation using the
proportion of weather-related delays to total flights in the other
categories. Finally, DOT adds these three sources of weather-related
delays to determine the share of all flight delays attributable to
weather. DOT estimates that, in 2007, about 44 percent of all delays as
measured in minutes were because of weather.
[10] Airlines report data to DOT in both minutes and the number of
flight operations (flights). In our July 2008 testimony, we reported
delays on the basis of the minutes of delay. In addition to delayed
flights, crew-scheduling problems can result in canceled flights, which
cannot be presented in number of minutes. Therefore, in this report, we
report delays on the basis of the number of flights. As a result, the
percentages in this report differ slightly from our July 2008
testimony. See GAO, National Airspace System: DOT and FAA Actions Will
Likely Have a Limited Effect on Reducing Delays during Summer 2008
Travel Season, [hyperlink, http://www.gao.gov/cgi-bin/getrpt?GAO-08-
934T] (Washington, D.C.: July 15, 2008).
[11] [hyperlink, http://www.gao.gov/cgi-bin/getrpt?GAO-08-934T].
[12] 14 C.F.R. § 121.471.
[13] 14 C.F.R. § 121.471.
[14] 14 C.F.R. § 121.471.
[15] Cabin crews have much more flexibility. For example, they have
fewer limitations on the type of aircraft to which they can be assigned
and can be scheduled up to 14 hours in a duty period.
[16] The results presented in this section pertain to 11 airlines that
collectively served just over 75 percent of all airline passengers in
2007 and reported flight delay and cancellation data to DOT. As such,
these data are illustrative of recent delays and cancellations due to
crew scheduling at these airlines and do not necessarily represent
results for the broader industry.
[17] Recently, the national aviation system and late-arriving aircraft
categories both accounted for higher percentages of delays than air
carrier: that is, about 8 percent for both categories in 2007 and about
9 percent for both categories during the first 3 months of 2008. Delays
for all reasons accounted for 24 percent of flights in 2007 and 26
percent of flights during the first 3 months of 2008.
[18] Cancellations accounted for about 2 percent of flights in 2007 and
about 3 percent of flights during the first 3 months of 2008.
[19] Some airlines we interviewed, as well as the industry association
that represents airlines, explained to us that crew members are
expected to report for work on time, and if a crew member is
consistently late for duty because of commuting problems, this would be
considered a performance problem, not a crew-scheduling problem.
Pilots, like other professionals, are expected to report for work on
time and rested, no matter where they choose to live.
[20] [hyperlink, http://www.gao.gov/cgi-bin/getrpt?GAO-08-934T].
[21] In July 2008, we reported that, for the past 10 years, the three
principal commercial passenger airports in the New York region--Newark
Liberty International, John F. Kennedy International, and LaGuardia--
have consistently ranked at or near the bottom of DOT's list of airport
on-time arrivals and departures. Since flights in and out of the New
York region typically account for about one-third of the total daily
flights flown throughout the national airspace system, delays in this
region can have a disproportionate impact on delays experienced
throughout the rest of the system. See [hyperlink,
http://www.gao.gov/cgi-bin/getrpt?GAO-08-934T].
[22] GAO, Federal Aviation Administration: Challenges Facing the Agency
in Fiscal Year 2009 and Beyond, [hyperlink, http://www.gao.gov/cgi-
bin/getrpt?GAO-08-460T] (Washington, D.C.: Feb. 7, 2008).
[23] As we reported in July 2008, to address delay and cancellation
problems beginning in summer 2008, DOT and FAA were implementing
several actions intended to reduce delays that we have categorized as
capacity-enhancing initiatives and demand management policies. Capacity-
enhancing initiatives are intended to increase the efficiency of
existing capacity by reducing delays and maximizing the number of
takeoffs and landings at an airport, while demand management policies
influence demand through administrative measures or economic
incentives. See [hyperlink, http://www.gao.gov/cgi-bin/getrpt?GAO-08-
934T].
[24] [hyperlink, http://www.gao.gov/cgi-bin/getrpt?GAO-08-460T].
[25] CrewPASS is expected to enhance security by providing flight crew
members with a dedicated portal for access to airport secure areas.
CrewPASS incorporates biometric processes with a secure database to
verify pilot identity and employment status.
[26] We requested data from and interviewed officials representing
AirTran Airways, Alaska Airlines, American Airlines and American Eagle,
Continental Airlines, Delta Air Lines, JetBlue Airways, Northwest
Airlines, Southwest Airlines, United Airlines, and US Airways. Skywest
Airlines did not respond to our request.
[27] Legacy airlines predate airline deregulation of 1978 and all have
adopted a hub-and-spoke network model that can be more expensive to
operate than a simple point-to-point service model. Low-cost airlines
have generally entered the market since 1978, are smaller, and
generally employ a less costly point-to-point service model. Regional
airlines generally employ much smaller (under 100 seats) aircraft and
provide service under code-sharing arrangements with larger legacy
airlines for which they are paid on a cost-plus or fee-for-departure
basis to provide capacity. Many regional airlines are owned by a legacy
parent, while others are independent.
[End of section]
GAO's Mission:
The Government Accountability Office, the audit, evaluation and
investigative arm of Congress, exists to support Congress in meeting
its constitutional responsibilities and to help improve the performance
and accountability of the federal government for the American people.
GAO examines the use of public funds; evaluates federal programs and
policies; and provides analyses, recommendations, and other assistance
to help Congress make informed oversight, policy, and funding
decisions. GAO's commitment to good government is reflected in its core
values of accountability, integrity, and reliability.
Obtaining Copies of GAO Reports and Testimony:
The fastest and easiest way to obtain copies of GAO documents at no
cost is through GAO's Web site [hyperlink, http://www.gao.gov]. Each
weekday, GAO posts newly released reports, testimony, and
correspondence on its Web site. To have GAO e-mail you a list of newly
posted products every afternoon, go to [hyperlink, http://www.gao.gov]
and select "E-mail Updates."
Order by Mail or Phone:
The first copy of each printed report is free. Additional copies are $2
each. A check or money order should be made out to the Superintendent
of Documents. GAO also accepts VISA and Mastercard. Orders for 100 or
more copies mailed to a single address are discounted 25 percent.
Orders should be sent to:
U.S. Government Accountability Office:
441 G Street NW, Room LM:
Washington, D.C. 20548:
To order by Phone:
Voice: (202) 512-6000:
TDD: (202) 512-2537:
Fax: (202) 512-6061:
To Report Fraud, Waste, and Abuse in Federal Programs:
Contact:
Web site: [hyperlink, http://www.gao.gov/fraudnet/fraudnet.htm]:
E-mail: fraudnet@gao.gov:
Automated answering system: (800) 424-5454 or (202) 512-7470:
Congressional Relations:
Ralph Dawn, Managing Director, dawnr@gao.gov:
(202) 512-4400:
U.S. Government Accountability Office:
441 G Street NW, Room 7125:
Washington, D.C. 20548:
Public Affairs:
Chuck Young, Managing Director, youngc1@gao.gov:
(202) 512-4800:
U.S. Government Accountability Office:
441 G Street NW, Room 7149:
Washington, D.C. 20548: