Military Aircraft
Information on Air Force Aerial Refueling Tankers Gao ID: GAO-03-938T June 24, 2003Both the Congress and the Department of Defense are concerned about the age of the U.S. aerial refueling fleet and its potential impact on the military services' ability to meet operational requirements. Aerial refueling provides a key capability that is essential to the mobility of U.S. forces. At present, the Air Force is in the early stages of planning for modernizing its aging fleet. In this testimony, GAO was asked to present its initial observations on (1) the status of the KC-135 fleet, including its age, projected life limits, and mission capable rates (i.e., the percent of time on average that the aircraft are available to perform their assigned mission); and (2) Air Force aerial refueling requirements.
The Air Force fleet of KC-135 aircraft (which, at 543 aircraft, represents the bulk of U.S. refueling capability) is an average of about 42 years in age. The Air Force projects that the KC-135 aircraft have between 36,000 and 39,000 lifetime flying hours; according to the Air Force, only a few KC-135s are projected to reach these limits before 2040, although at that time some of the aircraft would be close to 80 years old. KC-135s are being flown an average of about 435 hours per year, on average, since September 2001. As the fleet has aged, the aircraft have become expensive to maintain, averaging about $4.6 million per year in total operations and support costs for the least capable aircraft. Those costs include personnel, fuel, maintenance, and spare parts. KC-135s in the active duty forces are generally meeting the 85 percent goal for mission capable rates; rates were lower for aircraft in the reserve forces, ranging from 70 to 78 percent. The Air Force Reserve and Air National Guard operate over half of the KC-135s. In a 1996 report, GAO pointed out that the aging fleet of KC-135s would eventually need replacement and that the Department of Defense needed to start planning for the recapitalization of the fleet. At that time, the Department responded to our report saying that the current fleet would meet requirements "for the foreseeable future" and planned to begin procurement of new tankers around fiscal year 2013. In 2000, the Air Force conducted a study called the Tanker Requirements Study-05, but it was never formally completed. Therefore, DOD does not have a current, validated study on which to base the size and composition of either the current fleet or a future aerial refueling force. There is no effort currently under way to update the Air Force study or to conduct an analysis of alternatives for tanker modernization. The Air Force indicated recently that it plans to conduct a new Tanker Requirements Study in the fiscal year 2004-2006 time frame.
GAO-03-938T, Military Aircraft: Information on Air Force Aerial Refueling Tankers
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Testimony:
Before the Subcommittee on Projection Forces, Committee on Armed
Services, House of Representatives:
United States General Accounting Office:
GAO:
For Release on Delivery Expected at 2:00 p.m. EDT:
Tuesday, June 24, 2003:
Military Aircraft:
Information on Air Force Aerial Refueling Tankers:
Statement of Neal P. Curtin, Director Defense Capabilities and
Management:
GAO-03-938T:
GAO Highlights:
Highlights of GAO-03-938T, a testimony before the Subcommittee on
Projection Forces, Committee on Armed Services, House of
Representatives
Why GAO Did This Study:
Both the Congress and the Department of Defense are concerned about
the age of the U.S. aerial refueling fleet and its potential impact on
the military services‘ ability to meet operational requirements.
Aerial refueling provides a key capability that is essential to the
mobility of U.S. forces. At present, the Air Force is in the early
stages of planning for modernizing its aging fleet.
In this testimony, GAO was asked to present its initial observations
on
(1) the status of the KC-135 fleet, including its age, projected life
limits, and mission capable rates (i.e., the percent of time on
average that the aircraft are available to perform their assigned
mission); and
(2) Air Force aerial refueling requirements.
What GAO Found:
The Air Force fleet of KC-135 aircraft (which, at 543 aircraft,
represents the bulk of U.S. refueling capability) is an average of
about 42 years in age. The Air Force projects that the KC-135 aircraft
have between 36,000 and 39,000 lifetime flying hours; according to the
Air Force, only a few KC-135s are projected to reach these limits
before 2040, although at that time some of the aircraft would be close
to 80 years old. KC-135s are being flown an average of about 435 hours
per year, on average, since September 2001. As the fleet has aged, the
aircraft have become expensive to maintain, averaging about $4.6
million per year in total operations and support costs for the least
capable aircraft. Those costs include personnel, fuel, maintenance,
and spare parts. KC-135s in the active duty forces are generally
meeting the 85 percent goal for mission capable rates; rates were
lower for aircraft in the reserve forces, ranging from 70 to 78
percent. The Air Force Reserve and Air National Guard operate over
half of the KC-135s.
In a 1996 report, GAO pointed out that the aging fleet of KC-135s
would eventually need replacement and that the Department of Defense
needed to start planning for the recapitalization of the fleet. At
that time, the Department responded to our report saying that the
current fleet would meet requirements ’for the foreseeable future“ and
planned to begin procurement of new tankers around fiscal year 2013.
In 2000, the Air Force conducted a study called the Tanker
Requirements Study-05, but it was never formally completed. Therefore,
DOD does not have a current, validated study on which to base the size
and composition of either the current fleet or a future aerial
refueling force. There is no effort currently under way to update the
Air Force study or to conduct an analysis of alternatives for tanker
modernization. The Air Force indicated recently that it plans to
conduct a new Tanker Requirements Study in the fiscal year 2004-2006
time frame.
www.gao.gov/cgi-bin/getrpt?GAO-03-938T.
To view the full product, including the scope
and methodology, click on the link above.
For more information, contact Neal P. Curtin, (202) 512-4914 or
curtinn@gao.gov.
[End of section]
Mr. Chairman and Members of the Subcommittee:
I appreciate the opportunity to appear before you today to discuss the
important subject of aerial refueling for military aircraft. Aerial
refueling provides a key capability in enhancing the mobility of U.S.
forces. The Air Force is beginning planning for the modernization of
its aging aircraft fleet.
As you requested, my statement focuses on the following issues:
* KC-135 fleet status, including mission capable rates, age, and
projected life limits; and:
* Air Force aerial refueling requirements, including GAO's observations
and the results of GAO's 1996 Air Force air refueling study.
My statement is based on two published GAO reports[Footnote 1] and on
our on-going work for the Readiness Subcommittee of the House Armed
Services Committee. Because of the relatively short notice for the
hearing, I have kept my prepared statement short, focusing on some key
issues that will help update you with basic background information on
the tanker fleet, as your office had requested. As you know, DOD is in
the final stages of negotiating a lease agreement with Boeing for 100
new 767 aircraft that will be modified for use as tanker aircraft and
replace part of the current fleet. Because details of that agreement
have not been made public or provided to us, I am not in a position
today to discuss issues related to the lease.
Status of Aerial Refueling Fleet:
While numerous military aircraft provide refueling services, the bulk
of U.S. refueling capability lies in the Air Force fleet of 59 KC-10
and 543 KC-135 aircraft. These are large, long-range aircraft that have
counterparts in the commercial airlines, but which have been modified
to turn them into tankers. The KC-10 is based on the DC-10 aircraft,
and the KC-135 is similar to the Boeing-707 airliner. The KC-10
aircraft are relatively young, averaging about 20 years in age.
Consequently, much of the focus on modernization of the tanker fleet is
centered on the KC-135s. These were built in the 1950s and 1960s, and
now average about 42 years in age. Because of their large numbers, they
are the mainstay of the refueling fleet, and successfully carrying out
the refueling mission depends on the continued performance of the KC-
135s. Thus, recapitalizing this fleet of KC-135s will be crucial to
maintaining aerial refueling capability, and it will be a very
expensive undertaking.
Let me provide some additional background information on the KC-135
fleet:
* There are two basic versions of aircraft, designated the KC-135E and
KC-135R. The R model aircraft have been re-fitted with modern engines
and other upgrades that give them an advantage over the E models. The E
model aircraft on average are about 2 years older than the R models,
and the R models provide more than 20 percent greater refueling
capacity per aircraft.
* The E models are located in the Air National Guard and Air Force
Reserve. Active forces have only R models. Over half the KC-135 fleet
is located in the reserve component.
* While the KC-135 fleet averages over 40 years in age, the aircraft
have relatively low levels of flying hours. The Air Force projects that
E and R models have lifetime flying hours limits of 36,000 and 39,000
hours, respectively. According to the Air Force, only a few KC-135s
would reach these limits before 2040, but at that time some of the
aircraft would be about 80 years old.
* Flying hours for the KC-135s averaged about 300 hours per year
between 1995 and September 2001. Since then, utilization is averaging
about 435 hours per year.
* According to Air Force data, the KC-135 fleet had a total operation
and support cost in fiscal year 2001 of about $2.2 billion. The older E
model aircraft averaged total costs of about $4.6 million per aircraft,
while the R models averaged about $3.7 million per aircraft. Those
costs include personnel, fuel, maintenance, modifications, and spare
parts.
By most indications, the fleet has performed very well during the past
few years of high operational tempo. Operations in Kosovo, Afghanistan,
Iraq, and here in the United States in support of Operation Noble Eagle
were demanding, but the current fleet was able to meet the mission
requirements. Approximately 150 KC-135s were deployed to the combat
theater for Operation Allied Force in Kosovo, about 60 for Operation
Enduring Freedom in Afghanistan, and about 150 for Operation Iraqi
Freedom. Additional aircraft provided "air bridge" support for movement
of fighter and transport aircraft to the combat theater, for some long-
range bomber operations from the United States, and, at the same time,
to help maintain combat air patrols over major U.S. cities since
September 11, 2001.
Data on the mission capable rates for the KC-135 fleet are shown in the
following table. Mission capable rates measure the percent of time on
average that the aircraft are available to perform their assigned
mission. The goal for KC-135s is an 85 percent rate; the table shows
the number of aircraft in the different components along with the
mission capable rates for the period October 2001 through March 2002.
Table 1: Mission Capable Rates for KC-135 Aircraft:
Component: Active; Number of aircraft: 245; Mission capable rate
(percent): 85.
Component: Reserve R models; Number of aircraft: 52; Mission capable
rate (percent): 78.
Component: National Guard R models; Number of aircraft: 115; Mission
capable rate (percent): 78.
Component: Reserve E models; Number of aircraft: 16; Mission capable
rate (percent): 70.
Component: National Guard E models; Number of aircraft: 115; Mission
capable rate (percent): 76.
Source: Air Force data.
[End of table]
For comparison purposes, the KC-10 fleet is entirely in the active
component, and the 59 KC-10s had an average mission capable rate during
the same period of 81.2 percent.
The rest of the DOD refueling fleet consists of Air Force HC-and MC-130
aircraft used by special operations forces, Marine Corps KC-130
aircraft, and Navy F-18 and S-3 aircraft. However, the bulk of
refueling for Marine and Navy aircraft comes from the Air Force KC-10s
and KC-135s. These aircraft are capable of refueling Air Force and
Navy/Marine aircraft, as well as some allied aircraft, although there
are differences in the way the KC-10s and KC-135s are equipped to do
this.
DOD's Tanker Requirements and GAO's 1996 Air Force Refueling Study:
In our 1996 report, we pointed out that the aging fleet of KC-135s
would eventually need replacement and that DOD needed to start planning
for the recapitalization of the fleet. We recommended that DOD consider
looking at dual-use aircraft--an aircraft that could be used as a
tanker or as a cargo carrier, depending on mission requirements. The
KC-10 fleet is actually used in this way now. In response to our
recommendation, DOD agreed that it would consider such an option when
it did a comprehensive analysis of tanker requirements and
alternatives. However, the department also stated that the current
fleet would meet requirements for "the foreseeable future." Moreover,
in its response to our report, DOD stated that "While the KC-135 is an
average of 35 years old, its airframe hours and cycles are relatively
low. With proper maintenance and upgrades, we believe the aircraft may
be sustainable for another 35 years." At the time of our report, the
Air Force had deferred the start of KC-135 replacement from fiscal year
2007 to 2013. In discussions with the Air Force last year, officials
indicated that they had moved up that timetable to fiscal year 2009.
DOD does not have a current, validated study on which to base the size
and composition of either the current fleet or a future aerial
refueling force. An Air Force study called Tanker Requirements Study-05
(TRS-05) was conducted in 2000, but it was never formally completed nor
were its preliminary results released. Drafts of the study identified a
shortfall in tanker capability, but the study was based on the old
strategy of supporting two major theater wars. There is no effort under
way that we know of to update the TRS-05 study and release it or to
conduct an analysis of alternatives for tanker modernization. The Air
Force indicated recently that it planned to conduct a new Tanker
Requirements Study in the fiscal year 2004-2006 time frame.
Mr. Chairman, this concludes my prepared statement. I would be happy to
respond to any questions you or other Members of the Subcommittee may
have at this time.
Contacts and Acknowledgments For future contacts regarding this
testimony, please contact me at (202) 512-4914 or Brian Lepore at (202)
512-4523. Individuals making key contributions to this testimony
included Joseph J. Faley, Kenneth W. Newell, Tim F. Stone, and Susan K.
Woodward.
FOOTNOTES
[1] U.S. General Accounting Office, Air Force Aircraft: Preliminary
Information on Air Force Tanker Leasing, GAO-02-724R (Washington, D.C.:
May 15, 2002) and U.S. Combat Airpower: Aging Refueling Aircraft Are
Costly to Maintain and Operate, GAO/NSIAD-96-160 (Washington, D.C.:
August 8, 1996).
