U.S. Combat Air Power: Aging Refueling Aircraft Are Costly to Maintain and Operate (Chapter Report, 08/08/96, GAO/NSIAD-96-160)
GAO examined the military services' air refueling needs, focusing on
the: (1) cost to operate and maintain the air refueling fleet; and (2)
impact of air refueling missions on the active and reserve forces.
GAO found that: (1) the long-term serviceability of the KC-135 tanker is
questionable; (2) the cost per KC-135 flying hour is projected to
increase from $8,662 in 1996 to $10,761 in 2001; (3) as KC-135 aircraft
age, the number of aircraft available for operation declines; (4) from
fiscal year 1991 to 1995, labor hours for KC-135 overhauls increased 36
percent; (5) depot maintenance levels increased due to a shortage of
spare parts, maintenance delays, and reduced aircraft availability; (6)
the Air Mobility Command (AMC) doubts that KC-135 aircraft can operate
economically beyond 2020; (7) the Air Force could enhance the
operational flexibility of C-5A aircraft by acquiring dual-use aircraft
that combine airlift and refueling capabilities; (8) the Air Force is
procuring a new transport aircraft to replace its C-5A aircraft and a
new tanker to replace the KC-135; (9) the deployment rates for
individual tanker crew positions approached the 120-day management limit
during fiscal years 1994 and 1995; (10) air reserve units are operating
at 95 percent of their potential availability; and (11) the Air Force is
able to support its peacetime tanking requirements because many of its
reserve crew members volunteer their time and spend more than 100 days
annually training and flying sorties.
--------------------------- Indexing Terms -----------------------------
REPORTNUM: NSIAD-96-160
TITLE: U.S. Combat Air Power: Aging Refueling Aircraft Are Costly
to Maintain and Operate
DATE: 08/08/96
SUBJECT: Defense capabilities
Military airlift operations
Military aircraft
Military training
Aircraft maintenance
Defense contingency planning
Maintenance costs
Maintenance standards
Air Force reservists
Combat readiness
IDENTIFIER: Desert Storm
KC-135 Aircraft
S-3 Aircraft
KC-130 Aircraft
DOD Future Years Defense Program
KC-10 Aircraft
DC-10 Aircraft
C-5B Aircraft
C-17 Aircraft
KC-130 Aircraft
C-141 Aircraft
HC-130 Aircraft
KC-135R Aircraft
C/KC-135 Aircraft
KC-135E Aircraft
CFM-56 Engine
TF33 Engine
C-5A Aircraft
DOD Operation Provide Comfort
DOD Operation Uphold Democracy
DOD Operation Restore Hope
DOD Operation Deny Flight
F-16 Aircraft
F-111 Aircraft
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Cover
================================================================ COVER
Report to Congressional Committees
August 1996
U.S. COMBAT AIR POWER - AGING
REFUELING AIRCRAFT ARE COSTLY TO
MAINTAIN AND OPERATE
GAO/NSIAD-96-160
U.S. Combat Air Power
(701041)
Abbreviations
=============================================================== ABBREV
AFRES - Air Force Reserve
AMC - Air Mobility Command
ANG - Air National Guard
ARC - Air Reserve Component
DOD - Department of Defense
FYDP - Future Years Defense Program
Letter
=============================================================== LETTER
B-272009
August 8, 1996
Congressional Committees
Due to the changing nature of defense operations, the demands on the
services' air refueling fleet have not diminished since Operation
Desert Storm. However, the Air Force's principal tanker
aircraft--the KC-135s--are 30 to 40 years old and, as a result, are
taking progressively more time and money to maintain and operate.
Nevertheless, the Air Force has no immediate plans to replace the
KC-135s as it currently considers the replacement of other aircraft a
higher priority. Additionally, because of the demands on the tanker
fleet, Air Force active and reserve air refueling personnel have been
stressed to satisfy mission needs.
We examined the services' air refueling needs, the cost to operate
and maintain the air refueling fleet, and the impact that the air
refueling missions have on the active and reserve forces. This
report contains a recommendation to the Secretary of Defense
concerning future aircraft procurement that provides an opportunity
to enhance operational flexibility by acquiring a dual-use aircraft
that combines airlift and refueling capabilities.
This report was part of our broader effort to assess how the
Department of Defense might better adapt its combat air power to meet
future needs. We are addressing this report to you because of your
responsibility for the issues discussed and your interest in the
subject.
Please contact me at 202-512-3504 if you or your staff have any
questions concerning this report. Major contributors to this report
are listed in appendix IV.
Richard Davis
Director, National Security
Analysis
List of Congressional Committees
The Honorable Strom Thurmond
Chairman
The Honorable Sam Nunn
Ranking Minority Member
Committee on Armed Services
United States Senate
The Honorable Ted Stevens
Chairman
The Honorable Daniel K. Inouye
Ranking Minority Member
Subcommittee on Defense
Committee on Appropriations
United States Senate
The Honorable Floyd Spence
Chairman
The Honorable Ronald V. Dellums
Ranking Minority Member
Committee on National Security
House of Representatives
The Honorable C.W. Bill Young
Chairman
The Honorable John P. Murtha
Ranking Minority Member
Subcommittee on National Security
Committee on Appropriations
House of Representatives
EXECUTIVE SUMMARY
============================================================ Chapter 0
PURPOSE
---------------------------------------------------------- Chapter 0:1
Air refueling extends the operational range of the military services'
aircraft, increases combat capabilities, and enhances commanders'
flexibility in the use of aircraft. During Operation Desert Storm,
the Air Force routinely refueled Navy, Marine Corps, allied, and its
own aircraft. Since then, because of contingency and other
operations, the demands on the tanker fleet have not diminished, even
though the services have downsized in many other areas. During this
review, GAO examined the services' air refueling needs, the cost to
operate and maintain the air refueling fleet, and the impact that the
air refueling missions have on the active and reserve forces. This
report is one of a series of reports assessing how the Department of
Defense (DOD) might better adapt its combat air power to meet future
needs. Other reports in this series address close fire support,
interdiction, air superiority, suppression of enemy air defense, and
surveillance and reconnaissance.
BACKGROUND
---------------------------------------------------------- Chapter 0:2
The Air Force, Navy, and Marine Corps operate almost 900 tanker
aircraft, most of which are derivatives of cargo or commercial
aircraft. The Air Force owns about 690 of them, divided nearly
equally between active and reserve forces. The Air Force's KC-135
fleet of about 550 aircraft refuels Navy, Marine Corps, and Air Force
combat aircraft, strategic bombers, command and control aircraft, and
airlift aircraft. The Navy's S-3 refuels Navy and Marine Corps
aircraft during their launch from and recovery aboard aircraft
carriers, and the Marine Corps' KC-130 refuels Marine fighters and
helicopters. The U.S. Air Force Special Operations Command refuels
special operations helicopters with its HC-130s and MC-130s. Tanker
aircraft also airlift passengers and cargo. Over the next 6 years,
the services estimate they will spend about $2.4 billion a year to
operate these aircraft.
RESULTS IN BRIEF
---------------------------------------------------------- Chapter 0:3
Although the services' air refueling tanker aircraft meet current
needs, satisfying future requirements may be difficult. The
long-term serviceability of the KC-135 tanker fleet is questionable,
because the aircraft are 30 to 40 years old and, as a result, are
taking progressively more time and money to maintain and operate.
Furthermore, the Air Force could spend over $6 billion in
modifications and structural repairs to keep the KC-135 fleet
operational. Even though the Air Mobility Command doubts that the
KC-135 can be economically operated beyond 2020, it does not plan to
begin to replace them until around 2013, which is 6 years later than
planned a year ago. The Command deferred the replacement program
because it considers replacement of the C-5A transport beginning in
2007 a higher priority. However, the Air Force must eventually
replace the KC-135. As the Air Force makes plans for replacing its
C-5A, it has an opportunity to enhance operational flexibility by
acquiring a dual-use aircraft that combines airlift and refueling
capabilities. Current tankers have demonstrated the versatility and
value of a dual-use aircraft. For example, the KC-10, a derivative
of the commercial DC-10, was acquired as a dual-role aircraft and the
KC-135 is increasingly used to transport high-priority cargo and
passengers. The Air Force now plans to buy both a new transport
aircraft to replace its C-5A plus a new tanker later to replace the
KC-135. Since tanker aircraft are frequently used as cargo aircraft,
a dual-use aircraft is a viable option.
In recent years, Air Force active and reserve air refueling personnel
have been stressed to satisfy mission needs. As a result, active
duty tanker crews have approached the Air Force Chief of Staff's
management limit that active duty crews should not be away from their
home bases on temporary assignments more than 120 days a year. In
fiscal years 1994 and 1995, the deployment rates for individual
tanker crew positions, particularly navigators, approached the
120-day management limit, ranging from 103 to 117 days, depending on
crew position. To stay below the 120-day limit and relieve pressure
on active duty tanker crews, the Air Force has looked to the air
reserve units to take on more of the tanker workload in a role not
originally envisioned for reserve forces. Air Reserve Components
flew 27 percent of the total sorties and 30 percent of the total
flying hours flown by the Air Mobility Command and the Air Reserve
Components during fiscal year 1993. This increased in fiscal year
1995 to 44 percent of the sorties and 49 percent of the flying hours
flown by the Air Mobility Command and the Air Reserve Components.
Currently, the reserve force can maintain this level of operations
because many crew members volunteer extra time, thus exceeding the
reserves' legal training requirement of 38 days a year. Many, in
fact, have served over 100 days a year for training and flying
sorties. This effort is in addition to maintaining their civilian
jobs. According to service officials, these units are now operating
at about 95 percent of their potential availability.
PRINCIPAL FINDINGS
---------------------------------------------------------- Chapter 0:4
THE AGING TANKER FORCE IS
MORE DIFFICULT TO MAINTAIN
-------------------------------------------------------- Chapter 0:4.1
The KC-135 tankers, many of which are 40 years old, are the oldest
aircraft the services operate and are becoming more expensive to
operate
(the cost per KC-135 flying hour is projected to increase from $8,662
in 1996 to $10,761 in 2001). The military has little or no
experience operating and maintaining aircraft of this age, and there
are no commercial airline fleets of a comparable age. Consequently,
the Air Force only recently began to collect data to enable it to
predict how long or effectively these aircraft can continue to
operate.
As the KC-135 tankers age, they require more maintenance, reducing
the number of aircraft available for operations. For example,
between fiscal years 1991 and 1995, the labor hours planned to
complete depot overhauls of the KC-135s increased by about 36 percent
and the average time the aircraft spent in the depot increased from
158 days to 245 days. According to Air Force officials, the growth
in planned work included time to apply corrosion preventive compounds
and rewire significant portions of each aircraft. In addition,
shortages of spare parts, that were no longer in production or
stocked, and unplanned work, required to correct structural corrosion
and fatigue, contributed to maintenance delays and reduced aircraft
availability.
The Air Force could spend over $6 billion for a variety of
modifications and structural repairs to improve the reliability,
maintainability, and capability of its KC-135s. These include
re-engining KC-135Es, replacing major structural components because
of their age or susceptibility to stress corrosion, adding a
multipoint refueling capability to some of the aircraft, relocating
the navigator's instruments to the pilot and copilot positions,
installing improved compass and radar systems, installing a global
positioning system, and adding a ground collision avoidance system.
Of these potential modifications and repairs, the Air Force has
funded about $390 million for relocating the navigator's instruments
and installing the global positioning system and the improved
compasses and radars. According to Air Force officials, these
modifications and repairs should reduce maintenance costs and
increase the aircraft's capability. The Air Force has also funded a
$204 million program to modify about
45 KC-135 tankers with a multipoint capability to enhance their
ability to refuel Navy and Marine aircraft. The Desert Storm air
campaign and other operations illustrated both the feasibility and
necessity of cross-service air refueling operations. For example,
during Operation Desert Storm, Air Force tankers supported Navy,
Marine Corps, allied, and their own aircraft. However, adapters had
to be installed on the Air Force tankers in order to refuel Navy,
Marine Corps, and allied aircraft. This complicated joint mission
planning because properly configured tankers had to be available to
fill each service's special needs.
Though currently unfunded, the Air Force may also need up to $600
million to overhaul or upgrade about 600 engines for the KC-135s.
Even when overhauled, however, these engines will not meet Federal
Aviation Administration and international noise and air pollution
standards that become effective by 2000. As a result, the aircraft
may not be allowed to operate from some airfields, or their
operations may be restricted.
AGING TANKER AND AIRLIFTER
FORCES PROVIDE AN
OPPORTUNITY TO ACQUIRE A
DUAL-USE AIRCRAFT
-------------------------------------------------------- Chapter 0:4.2
Even though the Air Mobility Command has delayed consideration of a
replacement of the KC-135 from fiscal year 2007 to 2013 while
accelerating the replacement of the C-5A transport aircraft beginning
in 2007, the aging KC-135 tankers must ultimately be replaced.\1 The
anticipated acquisition of a C-5A replacement aircraft may provide an
excellent opportunity to satisfy both airlift and tanker needs.
Current tankers have demonstrated the versatility and value of a
dual-use, airlift-tanker aircraft. For example, the KC-10, a
derivative of the commercial DC-10, was acquired as a dual-role
aircraft. It demonstrated the viability of that concept during
Desert Shield/Storm during which it off-loaded almost 300 million
pounds of fuel (about 25 percent of the total) and transported about
54 million pounds of cargo and about 6,700 passengers. Similarly,
the KC-135 is increasingly used to transport high-priority cargo and
passengers. The Air Mobility Command allocates 26 of these aircraft
to wartime airlift tasks. In addition, some foreign nations have
converted commercial aircraft built by U.S. companies to provide air
refueling capabilities for their military aircraft.
--------------------
\1 The Air Force does not plan to replace the KC-135 at this time
because, it says, it cannot afford to simultaneously acquire a
replacement tanker, the C-17, a replacement for the C-5A transport
aircraft, and a new tactical aircraft such as the F-22.
PEACETIME ACTIVITIES HAVE
INCREASED DEMANDS ON THE
TANKER CREWS
-------------------------------------------------------- Chapter 0:4.3
The relocation of U.S. forces from overseas bases to the United
States and the increasing U.S. involvement in contingency and other
peacetime missions have increased the demands for air refueling.
While the number of tactical aircraft needing refueling is declining,
as is much of the military force, tanker support is increasingly
required. The drawdown of U.S. forces from overseas bases has added
to refueling requirements because of the need to refuel U.S.-based
tactical aircraft, enabling them to reach and return from their
overseas destinations and to facilitate their performance and
sustainment once they are in place. As a result, active duty tanker
crews have spent nearly 120 days a year on temporary assignments away
from their home bases. The Air Force Chief of Staff's management
limit is that its members not spend more than 120 days a year on
temporary assignments.
To stay below the 120-day temporary duty level and relieve pressure
on active duty tanker crews, air reserve units, which currently
maintain more than half of the KC-135 fleet, have taken on more of
the tanker workload in a role that was not originally envisioned for
the Air Reserve Component. As a force originally intended to augment
the active Air Force in time of war or national emergency, Air
Reserve Component personnel are legally required to serve 38 days a
year for training in peacetime: one weekend a month and 2 weeks of
annual active duty for training. However, Air Reserve Components
flew 27 percent of the total sorties and 30 percent of the total
flying hours flown by the Air Mobility Command and the Air Reserve
Components during fiscal year 1993. This increased in fiscal year
1995 to 44 percent of the sorties and 49 percent of the flying hours.
According to senior officials, the Air Reserve Component units are
now operating at about 95 percent of their potential availability.
While reserve crew members cannot be required to serve more than 38
days a year, many volunteer extra time. According to Air Force
Reserve officials' data, many crew members, in addition to meeting
the demands of their families and their civilian employers, averaged
more than 100 days a year supporting their units' training
requirements and air refueling sorties. Thus, the Air Force is able
to support peacetime tanking requirements in large part because of
the high tempo of active forces and the volunteerism in the Reserve
Components.
RECOMMENDATION
---------------------------------------------------------- Chapter 0:5
Because the services have successfully used dual-role aircraft for
both air refueling and airlift missions, GAO believes that a dual-use
replacement aircraft could fulfill both airlift and air refueling
missions. Accordingly, GAO recommends that the Secretary of Defense
require that future studies and analyses of replacement airlift and
tanker aircraft encompass both mission areas, with the goal to
identify the optimum size, mix, and time to procure a multimission
aircraft that, when combined with C-5Bs, C-17s, and KC-10s, will meet
those requirements. Such an aircraft would eliminate the need to
acquire two aircraft types, one for airlift and the other for
refueling.
AGENCY COMMENTS
---------------------------------------------------------- Chapter 0:6
In its comments on a draft of this report, DOD wrote that the report
accurately portrays some of the challenges facing the KC-135 fleet in
the coming years. It also said that it believes the current force
structure can adequately meet requirements for the foreseeable future
and agreed that future studies and analysis of replacing refueling
and airlift aircraft should include an analysis of using one aircraft
to accomplish both missions. It acknowledged that it was successful
in using a single aircraft, such as the KC-135 for both airlift and
refueling. However, DOD said that it could not commit to a dual-use
replacement aircraft until a study including operational issues is
completed. GAO agrees that such analysis should be conducted before
a decision is made. DOD did not comment on the stress of peacetime
activities on tanker crews in its written response. (See
app. I.)
INTRODUCTION
============================================================ Chapter 1
The Air Force, Navy, and Marine Corps tankers provide refueling
support to both land- and carrier-based aircraft. Tankers extend the
operational range of aircraft, enable aircraft to carry larger loads,
increase combat tempos, and enhance commanders' flexibility. As
world conditions have changed, so has the role of the tanker. While
the Air Force's tankers were once principally intended to support
strategic bombers, the tanker fleet is now responsible for various
air refueling tasks in support of both peace and wartime missions.
Although each service has its own specific air refueling needs,
cross-service refueling operations have become increasingly
important, as illustrated in Operation Desert Storm when Air Force
tankers routinely refueled Navy, Marine Corps, and allied aircraft in
addition to its own. Tankers also carry passengers and cargo. The
cost to operate the tanker fleet will average about $2.4 billion a
year between fiscal years 1996 and 2001.
THE CURRENT TANKER FLEET
---------------------------------------------------------- Chapter 1:1
The Air Force, Navy, and Marine Corps currently operate almost 900
tanker aircraft (see table 1.1). The Air Force owns about 690
tankers, or about 78 percent of the entire fleet, and is primarily
responsible for land-based peacetime and wartime refueling
operations. Before Operation Desert Storm, most of the Air Force
tanker fleet was in the active force. Today, however, about 50
percent of the overall Air Force tanker fleet is operated by the
reserve forces.\1
Table 1.1
Services' Tanker Aircraft and the
Aircraft They Support
Service Model Quantity Aircraft supported
-------- -------- -------- ----------------------------------------
Air Force
----------------------------------------------------------------------
HC-130 67 Special Operations Command helicopters
KC-10 59 Tactical aircraft/strategic bombers/
transports
MC-130 14 Special Operations Command helicopters
KC-135 552 Tactical aircraft/strategic bombers/
transports
Marine Corps
----------------------------------------------------------------------
KC-130 74 USMC helicopters/tactical aircraft
Navy
----------------------------------------------------------------------
S-3 118 Carrier-based tactical aircraft
======================================================================
Total 884
----------------------------------------------------------------------
--------------------
\1 As discussed in ch. 3, the reserve forces operate 54 percent of
the KC-135s.
TANKERS' EVOLVING SUPPORT ROLE
---------------------------------------------------------- Chapter 1:2
The current tanker fleet has evolved from post-World War II
requirements to contain Soviet military power. During the Cold War
era, the role of the KC-135 was to refuel strategic bombers that
would carry out the strategic nuclear war plan. Support of the plan
remained the KC-135s' primary mission until the demise of the Soviet
Union and the resultant reduction in the strategic threat. Tankers
were also used to support tactical operations: first during the
Vietnam conflict and later during Operations Desert Shield and Desert
Storm. As the threat changed, so did the role of the tanker. Today,
under the Department of Defense's (DOD) Planning Guidance, the
KC-10/KC-135 fleet is required to support operations in response to
major regional conflicts and the strategic nuclear war plan.
However, tankers are increasingly being tasked to support contingency
and other missions as both tanker and cargo aircraft.
REFUELING TASKS
-------------------------------------------------------- Chapter 1:2.1
Refueling aircraft as they deploy to and operate from overseas
locations is one of the major tasks of the tanker fleet. In-flight
refueling allows tactical and airlift aircraft to travel longer
distances with large cargo and passenger loads and also reduces the
need for access to overseas bases, thus minimizing potential
impediments to the movement of U.S. forces throughout the world.
Because they can be refueled in the air, combat air forces within a
theater can strike longer range targets or carry larger weapons loads
than their normal fuel/weapons loads would permit and can remain
airborne for longer periods of time. (Fig. 1.1 shows an Air Force
KC-135 refueling a KC-10.)
<PHOTO1x:PHOTO2.EPS>Figure 1.1: Air Force KC-135 Refueling a KC-10
Source: DOD.
Because of the return of U.S. forces from overseas, as bases were
closed due to downsizing, tankers are refueling more aircraft as they
deploy to and operate from distant trouble spots. The reduced size
of the U.S. force has made it necessary to rely more on joint
operations involving mixed groups of U.S. Air Force, Navy, Marine
Corps, and allied aircraft to capitalize on the unique strengths of
each service. For example, during Operations Desert Shield and
Storm, Air Force tankers transferred about 14 percent of 1.2 billion
pounds of fuel to Navy and Marine Corps aircraft and about 2 percent
to allied aircraft.\2 (Fig. 1.2 shows refueling in flight.)
<PHOTO1x:PHOTO3.EPS>Figure 1.2: Air Force KC-135 Refueling an F-16
Source: Air National Guard.
Each service has other, specific refueling requirements. Air Force
tankers are tasked to refuel strategic nuclear bombers, command and
control aircraft, and combat search and rescue helicopters. The Air
Force Special Operations Command also uses tankers to refuel both Air
Force and Army special operations helicopters. Navy tankers support
carrier-based aircraft and are critical to their safe recovery since
alternate airfields are frequently not available. Marine Corps
tankers support fighters and helicopters involved in expeditionary
and crisis response operations.
(Fig. 1.3 shows an Air Force HC-130 refueling a search and rescue
helicopter.)
<PHOTO1x:PHOTO1.EPS>Figure 1.3: HC-130 Refueling an HH-53
Source: DOD.
--------------------
\2 Allied aircraft were from Bahrain, Canada, Italy, Oman, Saudi
Arabia, and the United Arab Emirates.
AIRLIFT TASKS
-------------------------------------------------------- Chapter 1:2.2
In addition to refueling missions, several types of tanker aircraft
play significant roles in airlifting passengers and cargo. For
example, to meet wartime requirements, the Air Mobility Command's
(AMC) 1996 master plan allocates 37 KC-10s to airlift tasks and only
15 to air refueling. The nine remaining aircraft are for backup and
training. In addition, the Air Force has increased its use of
KC-135s to move high-priority cargo and passengers, allowing
airlifters such as the C-141 to be dedicated to the tasks only they
can accomplish. Between fiscal years 1993 and 1994, active Air Force
KC-135 cargo flights increased about 47 percent. Through fiscal year
1995, the Air Force bought 150 roller kits to enhance loading and
unloading cargo from the KC-135.\3 The master plan designates 26
KC-135s for wartime airlift requirements. Marine Corps KC-130s are
also frequently used to transport passengers and cargo. For example,
during Operation Desert Storm, KC-130s airlifted over 3,000
passengers and 8.1 million pounds of cargo.
--------------------
\3 Because the KC-135 was designed as a tanker, it does not have
rollers built into its floor as cargo aircraft do. The roller kits
can be moved to KC-135s as they are needed for cargo missions.
TANKER COSTS
---------------------------------------------------------- Chapter 1:3
Between fiscal years 1996 and 2001, the services' estimated annual
operating costs for tankers are about $2.4 billion. Personnel costs
account for about 32 to 34 percent of costs, while operations and
maintenance costs range from 55 to 61 percent. (See table 1.2)
Table 1.2
Funding for the Services' Tankers
(fiscal year 1994-2001)
(Dollars in thousands)
1996-
Appropriation 1994 1995 2001\a
---------------------------------- ---------- ---------- ----------
Aircraft procurement $114,418 $188,257 $1,281,823
Military construction 9,000 55,550 103,334
Military personnel 451,865 794,420 4,778,165
Operations and maintenance 1,194,893 1,431,964 8,484,022
RDT&E\b 11,540 23,006 13,520
======================================================================
Total $1,781,716 $2,493,197 $14,660,86
4
----------------------------------------------------------------------
Note: Funding is based on the 1996 Future Years Defense Program
(FYDP), which covers funding for the Air Force's KC-10s and KC-135s,
all Navy S-3 missions, and the Marine Corps' KC-130s. The table does
not include funding for the Air Force's H/MC-130 aircraft because
they are not separately identified in the FYDP.
\a Total for 6 years.
\b RDT&E is research, development, testing, and evaluation.
OBJECTIVES, SCOPE, AND
METHODOLOGY
---------------------------------------------------------- Chapter 1:4
During this review, we examined the services' air refueling needs,
the cost to operate and maintain the air refueling fleet, and the
impact that the air refueling missions have on the active and reserve
forces. This report is one of a series of reports assessing how DOD
might better adapt its combat air power to meet future needs. Other
reports in this series address close fire support, interdiction, air
superiority, suppression of enemy air defense, and surveillance and
reconnaissance.
To accomplish our objectives, we met with agency officials
responsible for program management and obtained pertinent documents
concerning the characteristics, missions, requirements, employment
concepts, and associated costs of the tanker aircraft. We did not
independently determine the reliability of the cost information. We
also obtained information concerning the maintenance of and planned
modifications to existing systems. We reviewed several studies and
reports addressing these topics. In addition, we discussed air
refueling issues with representatives of several research
organizations and defense-related companies. When analyzing the
problems of maintaining aging aircraft, we concentrated on the Air
Force's KC-135 because it makes up about two-thirds of the DOD's
tanker inventory.
To gain the operators' perspective of air refueling operations and
requirements, we met with officials of three unified commands,
various Navy and Air Force commands, and several tanker units. (See
app. II for a list of locations we visited during our review.)
During those visits, we discussed the commands' policies and
procedures for using air refueling assets. We also observed flight
and air refueling operations at several units and commands. We
observed carrier flight operations aboard the U.S.S. Theodore
Roosevelt during its predeployment training and discussed air
refueling issues with air wing personnel. During Joint Training
Exercise 95-2, we visited the Joint Force Air Component Commander
aboard the U.S.S. Mount Whitney and observed how tanker use was
integrated into the air tasking order planning process. During the
exercise, we also visited the U.S.S. Theodore Roosevelt and
accompanied the crew of a KC-135R from the 72d Air Refueling Squadron
on a refueling mission to observe how those plans were executed. To
gain a Special Operations Command perspective, we accompanied the
crew of an HC-130 of the 9th Special Operations Squadron on a night
helicopter refueling mission. We also accompanied the crew of a
KC-135E of the 108th Air Refueling Wing on a refueling flight.
We performed our work from June 1994 to February 1996 in accordance
with generally accepted government auditing standards.
THE SERVICES HAVE DEFERRED PLANS
TO REPLACE AGING TANKER AIRCRAFT
============================================================ Chapter 2
Although the services' tankers meet current Defense Planning Guidance
requirements, meeting future requirements may be difficult. Most
tankers, including all Air Force KC-135s, are 30 to 40 years old, and
are increasingly more expensive and time-consuming to support.
According to the Air Force, the cost per KC-135 flying hour is
projected to increase by about
24 percent, from about $8,700 in 1996 to $10,800 in 2001. In
addition, from fiscal year 1991 to fiscal year 1995, the average time
KC-135s spent in the depot for scheduled maintenance increased from
158 days to 245 days. Furthermore, the Air Force may spend over $6
billion in the coming years to sustain the KC-135 fleet and improve
reliability and capability. Despite the fact that costs to maintain
and operate the KC-135s have increased and its availability has
decreased, the Air Force has not estimated the KC-135's economic
service life and determined when to begin replacing it.
Nevertheless, AMC has delayed consideration of a tanker replacement
from fiscal year 2007 to fiscal year 2013.
TANKER FLEET MEETS CURRENT
NEEDS
---------------------------------------------------------- Chapter 2:1
According to recent Air Force and other studies, the current
KC-10/KC-135 force is generally adequate to meet the requirement to
support operations in response to major regional conflicts and the
strategic nuclear war plan. This determination is based on the
Defense Planning Guidance and current planning assumptions such as
the number and types of aircraft to be supported, the arrival time of
forces in the theater, the duration and nature of the operations, and
the availability of air bases. According to Air Force officials,
changes in any of these assumptions impact the tanker requirement.
For example, the tanker requirement would increase significantly if
U.S. forces were denied access to certain overseas air bases that
are critical to supporting the deployment of U.S. forces.
Conversely, requirements would decrease if the time frames for
deployment were lengthened. In a recent study of tanker
requirements, the Institute for Defense Analysis also noted that
tanker requirements are very sensitive to variations in those types
of factors.
However, because of the tankers' age, the services' ability to meet
requirements over the long term may be a challenge. As table 2.1
shows, many of the tanker aircraft entered service in the 1960s and
1970s and, in the case of the KC-135, as long ago as the mid-1950s.
Table 2.1
Age of the Services' Tanker Aircraft
Aircraft Service Age (years)
------------------------------ ------------------ ------------------
H/MC-130 Air Force 27 to 32
KC-10 Air Force 6 to 15
KC-135 Air Force 31 to 39
KC-130 Marine Corps 18 to 36\a
S-3 Navy 18 to 22
----------------------------------------------------------------------
\a KC-130s have been purchased more recently for the Marine Corps
Reserve squadrons.
Source: GAO analysis of service data.
Compared to commercial aircraft, most military tankers are
considerably older. As figure 2.1 shows, only about 4 percent of
U.S. commercial aircraft will be 25 years or older by 2000, whereas
all of the Air Force's KC-135s are already older, and by 2000, they
will be 35 to 43 years old.
Figure 2.1: Aircraft Ages
(year 2000)
(See figure in printed
edition.)
Source: GAO analysis of Air Force data.
The Air Force has initiated a program that it hopes will enable it to
determine the effects of corrosion on KC-135 structural life and
estimate the aircraft's remaining economic service life. The Boeing
Company, manufacturer of the KC-135, projected that the aircraft
could fly for many years beyond the turn of the century, based on the
average hours flown, and a projected utilization of about 300 hours a
year per aircraft. This projection, however, does not consider the
effects of corrosion, widespread fatigue damage, and stress corrosion
cracking on structural life, which can require major structural
modifications and parts replacement.
In the commercial sector, aircraft are generally considered old when
they reach the end of their economic design life--that lifespan over
which their designers originally believed they could be operated
economically. Economic life, which varies among different aircraft
types, has generally been stated in terms of years in service, number
of takeoffs and landings, and operating hours. Historically, when
commercial aircraft reached the upper limit of one of these measures,
they would have most likely been retired, generally before suffering
the damaging effects of corrosion, incurring higher operating costs,
and requiring increased maintenance. In recent years, however, air
carriers have tended to keep older aircraft in service even though
more time and money is needed to maintain them, in part to meet
increased demands for air travel.
EXPENSE AND TIME TO MAINTAIN
AGING TANKERS HAVE INCREASED
---------------------------------------------------------- Chapter 2:2
As shown in chapter 1, the costs to operate, support, and modernize
DOD's tanker aircraft are projected at about $2.5 billion annually
through 2001. The Air Force estimates that it will spend about $8.2
billion just for KC-135 direct operations and support during fiscal
years 1997-2001. Because the KC-135s are older, they require more
maintenance and longer stays in the depot during overhaul. As a
result, fewer aircraft are available to the squadrons.
INCREASE IN KC-135 OPERATING
AND SUPPORT COSTS
-------------------------------------------------------- Chapter 2:2.1
According to an Air Force automated budget system, the cost per
KC-135 flying hour is projected to increase by about 24 percent, from
$8,662 in 1996 to $10,761 in 2001. Increased projected costs of
people, fuel, and depot maintenance are the primary reasons for the
higher cost per flight hour. Costs for personnel are projected to
increase by about 12 percent, for fuel by 17 percent, and for depot
maintenance by 60 percent.
INCREASE IN TIME AND COSTS
FOR MAINTENANCE
-------------------------------------------------------- Chapter 2:2.2
The Air Force's goal to complete KC-135 depot overhauls is 153
calendar days. However, the actual time that KC-135s spent in the
depot for maintenance increased significantly during the past 4
years. In fiscal
year 1991, KC-135s spent an average of 158 days in the depot; by
fiscal
year 1995, that average had increased over 50 percent, to 245 days.
Numerous aircraft have been in the depot for hundreds of days. For
example, the percentage of KC-135s spending over 300 days in the
depot grew significantly during this period, from 6.6 percent of
aircraft inducted
(7 of 106) in fiscal year 1991 to 21.2 percent (24 of 113) in fiscal
year 1995.
In addition, the number of aircraft exceeding the 153-day turnaround
time goal has increased dramatically from 30 percent of the aircraft
inducted in fiscal year 1991 to 97 percent in fiscal year 1995.
Figure 2.2 shows the growth in the number of aircraft that have
exceeded the 153-day goal between fiscal years 1991 and 1995.
Figure 2.2: Increase in KC-135
Depot Overhaul Time
(See figure in printed
edition.)
Source: GAO analysis of Air Force data.
The Air Force cited the age of the aircraft and a lack of replacement
parts as primary reasons for the increased maintenance time. Other
contributing factors included the lack of information about the
condition of aircraft coming into the depot, and additional work
required to detect, repair, and prevent corrosion. The Air Force
indicated that, although the KC-135 design was considered
state-of-the-art in the 1950s, design features of the aircraft make
it vulnerable to corrosion damage. For example, when the planes were
built, sealant was not applied between overlapping surfaces
throughout the aircraft, and materials now considered susceptible to
corrosion and stress corrosion cracking were used in the aircrafts'
construction.
KC-135 depot maintenance time is significantly greater than that
experienced by commercial airline fleets during their periodic heavy
maintenance work, referred to as D checks, which most closely
represents Air Force depot maintenance. We previously reported that
D checks are performed every 3 to 9 years, and the maintenance time
required ranges from 10 to 60 days, depending on the airline.\1
KC-135s have been sent to the depot for scheduled maintenance every 4
years, with an average stay of 245 days in fiscal year 1995. Even
so, the interval for depot maintenance is now gradually being
extended to 5 years.
--------------------
\1 Aircraft Maintenance: Additional FAA Oversight Needed of Aging
Aircraft Repairs (Vol. I) (GAO/RCED-91-91A, May 24, 1991).
PLANNED DEPOT MAINTENANCE
WORK HAS GROWN
------------------------------------------------------ Chapter 2:2.2.1
The planned labor hours needed to complete standard depot maintenance
work on each KC-135 increased by about 6,300 labor hours (36 percent)
between fiscal years 1991 and 1995. In fiscal year 1991, the
standard work package, exclusive of any unplanned work, required
about 17,300 labor hours. In fiscal year 1995, this work package
labor hours increased to 23,600 hours. About 24,350 hours are
planned for fiscal year 1997. This growth includes time to apply
corrosion preventive compounds, remove and replace significant
portions of each airplane's wiring, and completely strip the paint
from each airplane.
UNPLANNED MAINTENANCE HAS
ALSO GROWN
------------------------------------------------------ Chapter 2:2.2.2
Once aircraft structures and assemblies are opened and closely
examined during maintenance, additional repairs or replacements of
components and structures are frequently identified. According to an
Air Force analysis of depot maintenance time for fiscal year 1994,
unplanned work on the KC-135 added an average of 61 days per aircraft
to depot maintenance on the aircraft. Significant portions of the
KC-135s' fuselage skins have had to be replaced due to corrosion.
Also, inspections revealed significant cracks in major structural
components such as fuselage bulkheads and wing production breaks,
which had to be replaced. In 1991, we reported that unforeseen,
unscheduled maintenance accounts for nearly one-half of the heavy
airframe maintenance done on commercial aircraft.\2 Unscheduled
maintenance increases to about 65 percent on aircraft over 10 years
old and continues to rise as they get older. This situation appears
to parallel the Air Force's experience in maintaining its older
tanker fleet and suggests that its KC-135 maintenance costs and
workload will continue to rise.
--------------------
\2 Aircraft Maintenance: Additional FAA Oversight Needed of Aging
Aircraft Repairs (Vol. I) (GAO/RCED-91-91A, May 24, 1991).
SOME DEPOT MAINTENANCE TO
BE DEFERRED BECAUSE OF
RISING COST ESTIMATES
------------------------------------------------------ Chapter 2:2.2.3
Depot overhauls planned for nine KC-135 tankers during fiscal year
1996 will be deferred to fiscal year 1997 because actual maintenance
costs are higher than budgeted amounts. Depot officials told us that
between submission and execution of the fiscal year 1996 budget
(about
18 months), additional tasks were added to the standard work package,
and hourly labor rates increased by about $10. As a result, AMC will
pay about $18 million more than planned for ongoing overhauls.
Consequently, overhauls of nine aircraft were deferred to adjust for
the increase.
EXTENDED DEPOT MAINTENANCE
REDUCES TANKER OPERATING
AVAILABILITY
-------------------------------------------------------- Chapter 2:2.3
When the number of KC-135s in depot maintenance exceeds 10 percent or
55 of the 552 current fleet, the squadrons have fewer aircraft than
planned for operations. At any given time, however, about 70 to
90--or an average of about 15 percent--of the 552 KC-135s are
undergoing scheduled maintenance. In the summer of 1995, 105
aircraft were in the depot-- about twice the number planned for any
one time. During our visit to Fairchild Air Force Base, Washington,
27 percent of the KC-135s were in depot maintenance.
AIR FORCE ACTIONS TO IMPROVE
AIRCRAFT AVAILABILITY AND
DEPOT TURNAROUND TIME
-------------------------------------------------------- Chapter 2:2.4
The KC-135 System Program Office at the Oklahoma City Air Logistics
Center developed an Aircraft Sustainment Master Plan to identify
actions required to sustain the C/KC-135 fleet. This plan includes
efforts to assess the impact of corrosion on the operational and
economic life of the aircraft.
The master plan cited replacement part shortages as a major cause of
extended depot stays for KC-135s. More than 500 items were
identified as critical to timely support. About 60 percent of these
items had not been authorized for stockage, while the other parts had
not been adequately stocked according to the Air Force. Stock levels
of these items were increased to meet higher parts failure rates
occurring due to the age of the aircraft. Critical items included
fuselage skins and major structural components. Outlays for these
parts rose from $5.8 million in fiscal
year 1992, to $70.6 million in fiscal year 1995. The Program Office
believes sufficient parts will be on hand by the end of calendar year
1996 to reduce depot delays caused by parts shortages.
Lack of information about the condition of aircraft before they
arrive at the depot has also extended depot maintenance time. To
remedy this condition, the Air Force plans to thoroughly inspect each
KC-135 about a year before it is scheduled for depot maintenance to
identify the aircraft's condition, forecast major parts requirements,
and reduce technical surprises once maintenance begins. A database
is being created to track depot and field maintenance actions and
inspection results, including corrosion information. This will
improve the knowledge of each aircraft's maintenance history.
Currently, there is no specific historical information available on
rework and repairs accomplished on the C/KC-135 fleet.
COSTS TO MODIFY KC-135S COULD
BE SUBSTANTIAL
---------------------------------------------------------- Chapter 2:3
The Air Force could spend over $6.1 billion in the coming years to
replace major structural components and other items to sustain the
KC-135 and improve its reliability, maintainability, and capability.
Although many of these modifications would not be required in a new
tanker, most will probably be made because they will be needed to
sustain the KC-135 fleet over several more decades. Table 2.2 lists
these modifications and their estimated cost. Modifications costing
about $1.1 billion have been funded.
Table 2.2
Possible KC-135 Modifications
(Dollars in millions)
Modification Estimated cost
---------------------------------------- ----------------------------
KC-135E engines $3,772.0\a
Structural components and aging items 1,717.8
Compass/radar/GPS (PACER CRAG) 386.5\b
Multipoint refueling 203.9\b
Ground collision avoidance system 19.5\b
Automatic communication processor 29.0\b
ARC-190 radio 22.3\b
======================================================================
Total $6,151.0
----------------------------------------------------------------------
\a About $436 million has been funded to replace engines on 20
aircraft. The Air Force is still considering whether to replace the
engines on 139 additional KC-135Es.
\b Funded.
KC-135E ENGINE OPTIONS COULD
BE COSTLY
-------------------------------------------------------- Chapter 2:3.1
Beginning by 2000, the Air Force could spend up to $600 million to
overhaul or up to $3.3 billion to replace the TF33 engines on 139 Air
Reserve Component (ARC) KC-135E tankers to keep them operational and
reduce support costs.\3 The TF33 engines are used, refurbished
commercial engines which, at current usage rates, will need a major
overhaul around the turn of the century. This will include related
repairs to cracked and corroded struts and engine shrouds.
Even if overhauled, the TF33 engines will not meet federal noise and
pollution standards. The Federal Aviation Administration will impose
even more stringent noise standards in 2000. Since many ARC aircraft
operate from commercial airports, they could be subjected to
operating hour restrictions or other penalties that could affect
tanker operations and flexibility.
An option is to replace the TF33s with the CFM-56 engine, which
according to Boeing meets noise and pollution standards, requires
less maintenance, has more thrust, and is more fuel efficient. The
increased thrust enables CFM-56-equipped KC-135s to take off from
shorter runways (increasing basing options) and, when combined with
better fuel efficiency, increases the amount of fuel available for
offloading by about 25 percent. The Air Force is conducting a
life-cycle cost analysis to determine the economic payback point for
replacing the TF33 engines with CFM-56 engines. It will use this
analysis to determine whether to modify the remaining ARC aircraft.
The average replacement cost per aircraft is about $24 million.
--------------------
\3 ARC tankers were fitted with the TF33 engine as a low-cost interim
measure to improve performance and operating capability until the
state-of-the-art CFM-56 engine could be installed. The Air Force is
currently replacing the TF33 engines on 20 ARC KC-135E aircraft with
CFM-56 engines at a cost of about $436 million. These aircraft
represent the last of the KC-135s for which re-engining funds have
been approved. The Air Force estimates that the last four aircraft
will be completed in fiscal year 1998. By the completion of the
currently approved program, it will have installed CFM-56 engines on
410 KC-135s.
MULTIPOINT REFUELING
CAPABILITY WILL ENHANCE
INTER-SERVICE SUPPORT
-------------------------------------------------------- Chapter 2:3.2
The Air Force plans to spend about $204 million ($33.5 million for
research, development, test, and evaluation, and $170.4 million for
procurement) to modify 45 KC-135s and buy 33 sets of wing refueling
pods to add a "multipoint" capability to enhance cross-service
refueling operations. Currently, the services lack standardized
refueling equipment. When Air Force tankers refuel Air Force
receiver aircraft, the boom operator maneuvers the tip of the
tanker's centerline refueling boom into a receptacle built into the
receiver aircraft's fuselage. In contrast, Navy, Marine Corps, and
most allied receiver aircraft have a refueling probe that the pilot
maneuvers into a funnel-shaped drogue basket mounted at the end of a
hose trailing from the tanker. For KC-135s to refuel probe-equipped
receivers, a short hose and basket adapter is added to the end of the
boom before flight. However, with the adapter installed, KC-135s
cannot refuel Air Force aircraft. This current arrangement
complicates mission planning and operations involving both types of
receiver aircraft.
The multipoint modification will alleviate these problems. Two
wing-mounted pods containing a retractable hose and refueling drogue
will be installed on some KC-135s, enabling modified tankers to
simultaneously refuel two probe-equipped Navy, Marine Corps, or
allied aircraft during joint operations. The modified tankers will
retain the boom to refuel Air Force aircraft.
DOD COULD ENHANCE OPERATIONAL
FLEXIBILITY WITH A DUAL-ROLE
TANKER/CARGO AIRCRAFT
---------------------------------------------------------- Chapter 2:4
Although the Air Force has not yet determined the remaining economic
service life of either the C-5A airlifter or the KC-135 tanker, the
Air Mobility Command has placed a higher priority on replacing the
C-5A beginning in fiscal year 2007, while deferring the start of a
KC-135 replacement from fiscal year 2007 to 2013. Since procurement
of a commercial-derivative aircraft could take as long as 4 to 6
years and development of a new military aircraft could take up to 12
years, the Air Force will need to quickly initiate studies to develop
a replacement strategy for mobility aircraft. We believe that a
dual-role cargo/tanker replacement may satisfy both needs. Current
tanker aircraft like the KC-10, the KC-135, and the KC-130 have
already demonstrated the versatility and value of a dual-role
aircraft. They have also shown the viability of using a commercial
design since the KC-10 was derived from the commercial DC-10 and
because both the Boeing-built KC-135 and its commercial 707 were
developed from a common design.
AMC, in its 1996 Air Mobility Master Plan (October 1995), which
reflects the Command's future vision and detailed plans for its total
force, expressed doubts that the KC-135 could continue to operate
economically over the next 25 years, to about 2020, because of
corrosion. Although 2020 is a much shorter period than the 2040 date
reflected in the 1995 Air Mobility Master Plan, AMC deferred the
start of the planned KC-135 replacement from 2007 to 2013. At the
same time, it accelerated plans to replace the C-5A aircraft
beginning in 2007. AMC, concerned about the economic life of the
C-5A, cited the airlifter's high operational and support costs and
low readiness and reliability as reasons to begin studying a
replacement for the C-5A.
Aging KC-135s will eventually have to be replaced. A replacement
tanker will be expensive--preliminary cost estimates range from about
$100 million to $150 million each--and will compete with other
acquisition programs. However, some Air Force officials indicated
that replacement may be less than one-for-one. Nevertheless, several
hundred new aircraft will have to be procured to replace over 550
KC-135s. If replacement does not begin until 2013, and only a
limited number of new aircraft are procured annually, many KC-135s
will be retained well past 2020. Figure 2.3 shows a tanker force mix
projected by AMC if 12 new aircraft were delivered in 2013, with 18
aircraft delivered each year thereafter. At that rate, the Air Force
would have only 138 new aircraft by 2020, with
406 KC-135s remaining.
Figure 2.3: KC-135/Replacement
Tanker Force Mix
(See figure in printed
edition.)
Source: GAO analysis of Air Force data.
The eventual need to replace both KC-135s and C-5As presents the Air
Force with an opportunity to possibly meet air refueling and airlift
needs with a single type of aircraft. A significant portion of the
cost to acquire separate tanker and cargo aircraft might be avoided
if the Air Force considered one type of aircraft capable of filling
both airlift and tanker needs. It has already demonstrated the
value, versatility, and feasibility of dual-mission capability in its
KC-10 aircraft. The KC-10 is a swing role tanker/airlift aircraft
that can be used to refuel aircraft and carry cargo simultaneously,
or perform either mission exclusively. It has a 342,000 pound fuel
capacity and can be refueled in flight itself, thus extending its
range and the time it can remain airborne. It can carry 79
passengers and crew, and up to 170,000 pounds of oversized and bulk
cargo. According to AMC, the KC-10 provides 13 percent of the total
U.S. military organic airlift capacity. In Operations Desert
Shield/Desert Storm, KC-10s conducted over 12,200 air refuelings and
offloaded 297.6 million pounds of fuel
(25 percent of the total), carried 53.7 million pounds of cargo, and
transported over 6,700 passengers.
Compelling reasons to consider a joint cargo/tanker aircraft include
the added utility of this combination, airframe commonality,
increased reliability and maintainability, and the reduced operating
and maintenance expenses of modern aircraft. Improved reliability
and maintainability increases the number of aircraft available for
operations, thereby increasing the effectiveness of a smaller force.
The operating and support costs of a modern state-of-the-art aircraft
can be far less than the 1950s vintage KC-135 because, in part, a new
aircraft incorporates modern manufacturing techniques and stronger,
more corrosion-resistant and fatigue-resistant materials.
CONCLUSION
---------------------------------------------------------- Chapter 2:5
Although the services' air refueling tanker aircraft meet current
needs, satisfying future requirements may be difficult. The
long-term serviceability of the KC-135 tanker fleet is questionable,
as the aircraft are 30 to 40 years old and are taking progressively
more time and money to maintain and operate. Furthermore, the Air
Force could spend over $6 billion in modifications and structural
repairs to keep the KC-135 fleet operational. However, even though
the Air Mobility Command doubts that the KC-135 can be economically
operated beyond 2020, it has delayed consideration of a replacement
program until around 2013 because it considers replacement of the
C-5A transport by 2007 a higher priority. Although service officials
say they cannot currently afford to acquire a new tanker, the Air
Force must eventually replace the KC-135. As the Air Force considers
replacing its C-5A, it has an opportunity to enhance operational
flexibility by acquiring a multiuse aircraft that combines transport
and refueling capabilities. The Air Force now plans to buy both a
new transport aircraft to replace its C-5A and a new tanker later to
replace the KC-135. Since tanker aircraft are also used as cargo
aircraft, such as in the case of the KC-10, a dual-use aircraft is a
viable option.
RECOMMENDATION
---------------------------------------------------------- Chapter 2:6
Because the services have successfully used variants of commercial
aircraft for both air refueling and cargo missions, we believe that a
dual-use replacement aircraft could fulfill both airlift and air
refueling missions. Accordingly, we recommend that the Secretary of
Defense require that future studies and analyses of replacement
airlift and tanker aircraft consider accomplishing the missions of
the C-5A and KC-135 with a dual-use aircraft that, when combined with
C-5Bs, C-17s, and KC-10s, will meet those requirements. This could
eliminate the need to acquire two aircraft types, one for airlift and
the other for refueling.
AGENCY COMMENTS
---------------------------------------------------------- Chapter 2:7
DOD agreed that future analyses regarding replacement of refueling or
airlift aircraft should include a study of accomplishing the dual
mission of airlift and refueling with one aircraft. However, it was
concerned about how a dual-use aircraft would be used and whether one
mission area might be degraded in order to accomplish the second
mission. Accordingly, it would not commit to a dual-use aircraft
until future analyses are done on operational issues and on the
potential performance of a dual-use aircraft fulfilling both airlift
and refueling missions and meeting deployment and employment
requirements.
We agree that future analyses should address operational issues and
whether a dual-use aircraft, used in conjunction with other air
mobility assets, can perform both the airlift and aerial refueling
mission, either separately or concurrently, without jeopardizing
either mission. Such analyses will necessarily encompass a wide
range of issues, including the air mobility requirements for
deployment, employment, sustainment, and redeployment of U.S.
forces; current and planned capacity, capability, and force
structure; enroute and in-theater basing and infrastructure; and
reliability, maintainability, and supportability.
Although DOD asserted that there are opposing requirements between
the airlift and refueling missions, the KC-10, through its ability to
either perform each mission exclusively, or perform both missions
simultaneously, has demonstrated the value and flexibility of
dual-use aircraft. We believe that a properly sized force of
dual-use replacement aircraft, used in conjunction with other air
mobility assets such as the C-17s, could meet airlift requirements,
while still providing necessary air refueling. Like the KC-10, that
replacement could perform these missions exclusively or concurrently,
depending on the circumstances and conditions at hand. We believe
there are a range of alternative aircraft that could be considered
for a dual-use replacement.
PEACETIME ACTIVITIES ARE STRESSING
THE TANKER FLEET'S SUPPORT
CAPABILITIES
============================================================ Chapter 3
With more than half of the Air Force's KC-135s in its possession, ARC
units augment the active force in war and peacetime, as needed.\1 As
the demand for air refueling has not diminished in proportion to the
reduction in the number of tactical aircraft, the Air Force is
increasingly relying on ARC to provide air refueling for peacetime
missions. Because the United States has been involved in contingency
operations in remote areas of the globe, tanker aircraft are
frequently called on to refuel previously forward-deployed military
aircraft as they fly to and from their destinations and to facilitate
and sustain the performance of their mission once they are in
place.\2 Meeting these demands has meant higher deployment rates for
the active force and an increased share of the refueling workload for
ARC. The ARC is able to meet these commitments through high
volunteerism rates. However, the increased peacetime workload is
stretching reserve crews' availability far beyond the point (38 days)
that they are legally required to train.
--------------------
\1 The ARC comprises the Air National Guard (ANG) and Air Force
Reserve (AFRES), created in 1947 and 1948, respectively. Under 10
U.S.C. 10102, ARC members can be mobilized to augment the active Air
Force during a war or national emergency or as the national security
may require.
\2 Contingency operations are military operations that exceed the
routine deployment or stationing of U.S. forces abroad but fall
short of large-scale theater warfare.
INCREASED PEACETIME ACTIVITY
RESULTS IN HIGH DEPLOYMENT
RATES FOR THE ACTIVE FORCE
---------------------------------------------------------- Chapter 3:1
As the Soviet threat collapsed, the U.S. military faced new
operating realities. Although the overall size of U.S. forces,
defense budgets, and overseas presence have been significantly
reduced, U.S. forces continue to deploy for traditional combat
training and to participate in contingency operations. This has
resulted in increased deployments that have stressed active duty
service members who must spend longer temporary duty assignments away
from home.
Since Operations Desert Shield and Storm, the Air Force has asked ARC
to support a number of contingency operations. These contingency
operations include Provide Comfort (northern Iraq), Uphold Democracy
(Haiti), Restore Hope (Somalia), and Deny Flight (Bosnia). In
December 1992, as part of Operation Restore Hope, 381 AFRES
volunteers were placed on active duty for 31 days, flying 190
sorties, airlifting
1,076 passengers and 1,504 tons of cargo, and offloading nearly 1.8
million pounds of fuel in flight. Similarly, during the last quarter
of fiscal year 1994 and the first quarter of fiscal year 1995, ANG
provided 1,071 tanker personnel and 37 aircraft for Deny Flight
operations.
Air Force officials also told us that the drawdown of U.S. forces
from overseas bases has added to air refueling requirements because
of the need to refuel U.S.-based tactical aircraft to enable them to
reach and return from their overseas destinations and to facilitate
their performance and sustainment of their missions once they are in
place. According to AMC officials, before Operations Desert Shield
and Storm, contingency operations accounted for less than 2 percent
of the total air refueling activity. Since then, these operations
have accounted for an average of more than 20 percent of the mission.
In addition, contingency air refueling directly contributed to actual
flying hours exceeding planned flying hours by an average of 11
percent in the post Desert Shield/Storm era. Figure 3.1 shows the
increase in air refueling activity of the European and Pacific
Commands since 1990.\3 Other factors also contributed to the
increased air refueling demand. For example, since the drawdown of
U.S. forces, the F-16 has become the primary fighter aircraft in the
European Command. Because it cannot fly as far as other fighters
without being refueled, it is more dependent on tankers than, for
example, was the F-111. Thus, while fewer fighter aircraft are in
the theater, those remaining are more dependent on tankers than
before. In addition, because fewer units are based in Europe,
ongoing missions such as the Bosnian operation require the periodic
rotation and replacement of personnel, equipment, and supplies, and
each trip across the Atlantic requires tanker support.
Figure 3.1: KC-135 Flying
Hours in Overseas Commands
(See figure in printed
edition.)
Source: GAO analysis of Air Force data.
Because of the increase in peacetime activity, active duty tanker
crews are spending significant amounts of time on temporary duty away
from their home stations. In February 1995, the Secretary of the Air
Force and the Chief of Staff jointly testified before Congress that
active duty personnel deployments increased four-fold over a 4-year
period. In fiscal years 1994 and 1995, the deployment rates for
individual tanker crew members, particularly navigators, approached
the 120-day management limit, ranging from 103 to 117 days, depending
on crew position.\4 We recently reported that, with the exception of
the Navy, unit personnel described a variety of stresses on
individuals and families of high-deploying units in the active force,
including difficulties in financial management, retention problems,
high divorce rates, substance abuse, and career hardships.\5
--------------------
\3 These operating commands are directly affected by the drawdown
from overseas bases. In addition, a number of recent contingency
operations have operated from the European Command's theater of
operations. It should be noted, however, that due to limitations in
AMC's historical tanker reports, the level of tanker activity
occurring in Europe Command's theater is understated. It includes no
tanker activity of ARC units, or of other commands' assets
temporarily under the operational command of the Europe Command.
Further, tanker activity supporting Southern Watch, an operation
directed by Central Command, is reported by the various participating
commands that own the tanker assets employed in the operation.
\4 Currently there is an Air Force-wide shortage of navigators.
\5 Military Readiness: A Clear Policy Is Needed to Guide Management
of Frequently Deployed Units (GAO/NSIAD-96-105, Apr. 8, 1996).
RESERVE COMPONENT IS PERFORMING
MORE REFUELING MISSIONS
---------------------------------------------------------- Chapter 3:2
To hold the line on active duty deployment rates, the Air Force has
increasingly relied on ARC volunteers to take on more and more of the
workload. In fiscal year 1993, ARC crews flew 27 percent of the
total sorties and 30 percent of the total flying hours flown by ARC
and AMC. In fiscal year 1995, ARC flew 44 percent of the total
sorties and 49 percent of the total flying hours flown by ARC and
AMC. ARC officials indicated that ARC is currently operating at
about 95 percent of its availability.
Today, ARC maintains more than half of the KC-135 fleet. By the end
of fiscal year 1996, based on congressional direction, the active Air
Force will have transferred about 296, or 54 percent, of the KC-135
tankers to ARC. With 19 tanker units and 224 aircraft, ANG has the
majority of the ARC tankers; AFRES has 7 tanker units and 72
aircraft. A typical ARC tanker unit is comprised of a mix of
part-time and full-time crews.
During peacetime, DOD may gain access to reservists in two ways.
Under 10 U.S.C. 12304, the President may order reservists to serve
on active duty involuntarily. Also, under 10 U.S.C. 12301(d), DOD
can activate any reservist with his or her consent. Unless
mobilized, ARC members cannot be required to serve more than 38 days
in prescribed training activities to meet their service
obligations.\6 However, it is not unusual for this largely part-time
force to exceed this minimum training requirement. According to
senior ANG and AFRES officials, traditional part- time reservists can
reasonably expect to serve at least 110 duty days a year. This
includes
50 days at the home unit and 60 days a year on deployment (time away
from their jobs and families). According to an ANG training
official, air crew generally train an additional 48 flying and flight
training periods, 3 school training days on flight simulators, 1
exercise or deployment lasting 5 to 10 days, and a number of special
training days, the length depending on the type of aircraft. In
fiscal year 1994, KC-135 AFRES crews averaged 50 crew days away from
the home unit; KC-135 ANG crews averaged 68 crew days away from the
home unit, facilitated by high rates of volunteerism. In fiscal year
1995, the AFRES crews averaged 57 crew days away, while the ANG crews
averaged 52 crew days away.
But the availability of individual reservists and reserve units to
perform tanker missions can be limited by many factors. For an
individual, these factors include whether the member has a full- or
part-time civilian job, the nature of the job, and the willingness of
the employer to grant time away from the job. According to the Air
Force Reserve Commander's Review of 1995, a civilian who is not
affiliated with the ARC would work approximately 221 days a year,
leaving 144 days for nonwork activities. However, a typical air crew
member works 221 days at a civilian job and approximately 100 to 120
days at the reserve job, leaving 24 to 44 days free time. Fulfilling
these reserve duties may necessitate reservists' using their personal
vacation time. The availability of the traditional Guard air crew
members is also affected by civilian employment limitations, the
influence of economic cycles, and can vary greatly among units. The
state of the local economy and airline hiring directly affect aircrew
availability. If civilian employment is down, part-time crew members
without full-time civilian employment can serve more days in the
reserves. When the economy is booming, and more jobs are available,
this personnel resource is diminished.
The limited availability of ARC personnel also precludes them from
supporting some longer term operations. For example, the Commander,
Central Command, Air Force, requires that all personnel supporting
Operation Southern Watch serve a minimum of 91 days in theater. This
effectively precludes the use of ARC tanker units and personnel
because ARC personnel are generally required to serve on active duty
for only a 14-day period.
The Air Force has acknowledged that the limited availability of ARC
personnel affects AMC in terms of contingency response time and
operations tempo. According to the current Air Mobility Master Plan,
the transfer of tanker and airlift aircraft to ARC lengthens AMC's
contingency response time unless ARC is mobilized. Furthermore, the
plan states that continuing mobility requirements and a high
operations tempo will demand more from AMC active duty personnel,
which may contribute to retention problems in the late 1990s.
--------------------
\6 According to DOD Directive 1215.6, AFRES personnel are required to
serve a minimum of 38 training days a year, and ANG personnel are
required to serve a minimum of 39 training days a year.
OFFICIALS SAY ACTIVE AND
RESERVE ASSIGNMENT MIX NEEDS
REEVALUATION
---------------------------------------------------------- Chapter 3:3
In a 1994 speech, General Fogelman, the Air Force Chief of Staff,
responded to the question: Are we overtasking our people so they are
not ready for combat? with the following remarks:
We do not have a hollow force problem . . . we have an
OPTEMPO problem. We have some folks on the road too much . .
. One of my challenges is to find ways to spread out the TDY
burden . . . [One way may be to] redistribute some force
structure between the Guard or Reserve and active duty units. .
. . But, there is a limit on the amount of volunteerism we can
expect from our citizen-airmen. . . . That's far too
much."\7
Several recent studies have discussed the high operating tempos
currently associated with peacetime operations and use of the ARC to
provide relief to the active duty units. In March 1995, we reported
on the stress of high deployment rates that result from the repeated
use of certain active duty support units', including specialized Air
Force aircraft, extended participation in multiple and/or large scale
peace operations. This also involved the use of the reserve forces
to provide relief. Changing the mix of active and reserve units was
one option suggested to DOD to allow it to meet the demands of peace
operations.\8 A September 1995 Rand report on Air Force needs
appropriate for responding to crises and lesser conflicts, suggested
the option that more of the support forces needed for these
operations be retained by the active component.\9
--------------------
\7 "Core Competencies -- New Missions: The Air Force in Operations
Other Than War", Gen. Ronald R. Fogelman, Chief of Staff, United
States Air Force, remarks to the American Defense Preparedness
Association Symposium, Washington, D.C., December 15, 1994.
\8 Peace Operations: Heavy Use of Key Capabilities May Affect
Response to Regional Conflicts (GAO/NSIAD-95-51, Mar. 8, 1995).
\9 An Air Force for Crises and Lesser Conflicts, Carl H. Builder and
Theodore Karasik, MR- 626-AF, Rand, Santa Monica, California, 1995.
CONCLUSION
---------------------------------------------------------- Chapter 3:4
As noted earlier, the Air Force Chief of Staff testified that in
dealing with the issue of lowering the time personnel are away from
home on deployment, the Air Force has looked to ARC to relieve active
duty units in more mission areas than ever before. In fiscal year
1995, the reserve fleet flew almost half of ARC and AMC air refueling
flight hours. They were able to do this because of the high rate of
volunteerism. But ARC officials believe they are at about 95 percent
of availability. In the last few years, ARC has been called upon
more and more to support tanker missions of the active force.
However, there may be a practical limit to the workload ARC can
assume, because as the ANG KC-135 Operations Council noted in April
1995, "the Ops tempo has been sustained at a very high level for the
past few years . . . [and] the ability to surge for other than
real world emergencies is diminished."
(See figure in printed edition.)Appendix I
COMMENTS FROM THE DEPARTMENT OF
DEFENSE
============================================================ Chapter 3
(See figure in printed edition.)
AIR FORCE AND NAVY AIR REFUELING
SYSTEMS
========================================================== Appendix II
The Air Force, Navy, and Marine Corps use two different refueling
systems. Air Force fixed-wing aircraft employ a boom/receptacle
refueling system. A telescoping tube, or boom, is mounted near the
tanker aircraft's tail while the aircraft to be refueled (receiver
aircraft) is equipped with a matching receptacle. During refueling,
the receiver aircraft's pilot positions the aircraft below and behind
the tanker aircraft. The boom operator aboard the tanker then
extends the tip of the boom into the receiver aircraft's receptacle.
The Air Force originally adopted this system because its relatively
high fuel transfer rate was well suited to refueling larger aircraft
such as the bomber fleet.
In contrast, Navy, Marine Corps, and most allied fixed-wing aircraft
as well as all air-refuelable helicopters (including Air Force
helicopters) use a probe/drogue system. During air refueling, the
tanker aircraft trails a flexible hose that ends in a funnel-shaped
drogue basket.\1 To refuel, the pilot of the receiver aircraft or
helicopter approaches the basket and inserts a pipe (the probe)
mounted on the receiver aircraft into the basket.
The Air Force's KC-135s--the most common tanker--are equipped with
centerline refueling booms. Therefore, boom drogue adapter kits must
be installed on the booms prior to the aircrafts' takeoff to enable
them to refuel Navy, Marine Corps, and allied probe-equipped
aircraft. Thus, to properly support operations involving mixed
groups of Air Force, Navy, Marine Corps, or allied aircraft, tanker
planners must ensure that enough tankers are provided to offload the
amount of fuel needed and that the tankers are properly configured
for the type of aircraft to be refueled. The KC-135s cannot refuel
Air Force or allied receptacle-equipped aircraft when the adapters
are installed. KC-10 tankers are equipped with a single hose and
drogue in addition to their booms and, as a result, can refuel probe-
and receptacle-equipped aircraft on the same mission. In addition,
20 KC-10s are being modified to accept wing-tip mounted pods that
allow the aircraft to refuel two probe-equipped aircraft
simultaneously.\2
--------------------
\1 The hose is stored on a reel mounted in a wing pod or within the
aircraft, depending on the type of aircraft, when refueling
operations are not underway.
\2 A total of 15 pod kits will be bought.
LOCATIONS VISITED
========================================================= Appendix III
During our review, we visited the following locations:
WASHINGTON, D.C., AREA
----------------------------------------------------- Appendix III:0.1
-- Office of the Secretary of Defense
-- Office of the Chairman, Joint Chiefs of Staff
-- Headquarters, U.S. Air Force
-- Office of the Chief of Naval Operations
-- Headquarters, Marine Corps
-- National Guard Bureau
-- Headquarters, Naval Air Systems Command
-- Air National Guard Readiness Center
-- Commission on Roles and Missions of the Armed Forces
-- Institute for Defense Analysis
EGLIN AIR FORCE BASE,
FLORIDA, AREA
----------------------------------------------------- Appendix III:0.2
-- Headquarters, U.S. Air Force Special Operations Command
-- 9th Special Operations Squadron
-- 20th Special Operations Squadron
HONOLULU, HAWAII, AREA
----------------------------------------------------- Appendix III:0.3
-- Headquarters, U.S. Pacific Command
-- Headquarters, U.S. Pacific Air Force
-- Headquarters, U.S. Pacific Fleet
-- Headquarters, Fleet Marine Force Pacific
-- Headquarters, Hawaii Air National Guard
-- 203d Air Refueling Squadron
MACDILL AIR FORCE BASE,
FLORIDA
----------------------------------------------------- Appendix III:0.4
-- Headquarters, U.S. Central Command
-- Headquarters, U.S. Special Operations Command
MARINE CORPS AIR STATION, EL
TORO, CALIFORNIA, AREA
----------------------------------------------------- Appendix III:0.5
-- Headquarters, 3d Marine Air Wing
-- Marine Air Group 11
-- Marine Air Group 16
-- VMGR-352
-- VMFA-235
NORFOLK, VIRGINIA, AREA
----------------------------------------------------- Appendix III:0.6
-- U.S. Atlantic Command
-- Air Combat Command
-- Headquarters, U.S. Atlantic Fleet
-- U.S. Naval Air Forces, Atlantic
-- Carrier Air Wing Eight
-- Carrier Air Wing Seventeen
SCOTT AIR FORCE BASE,
ILLINOIS
----------------------------------------------------- Appendix III:0.7
-- Headquarters, U.S. Transportation Command
-- Headquarters, Air Mobility Command
OTHER MILITARY COMMANDS,
UNITS, AND ACTIVITIES
----------------------------------------------------- Appendix III:0.8
-- Headquarters, U.S. Air Force, Europe, Ramstein Air Base,
Germany
-- Headquarters, U.S. Central Air Force, Shaw Air Force Base,
South Carolina
-- U.S. Naval Air Forces, Pacific, San Diego, California
-- Carrier Air Wing Two, San Diego, California
-- Oklahoma City Air Logistics Center, Tinker Air Force Base,
Oklahoma
-- 72d Air Refueling Squadron (Air Force Reserve),
-- 722d Air Refueling Wing, March Air Force Base, California
-- 92d Air Refueling Wing, Fairchild Air Force Base, Washington
-- 108th Air Refueling Wing (Air National Guard), McGuire Air Force
Base, New Jersey
-- 163d Air Refueling Group (Air National Guard), March Air Force
Base, California
-- 168th Air Refueling Squadron (Air Force Reserve), March Air
Force Base, California
-- U.S.S. Mount Whitney
-- U.S.S. Theodore Roosevelt
DEFENSE-RELATED COMPANIES
----------------------------------------------------- Appendix III:0.9
-- AEL Industries, Inc., East Alton, Illinois
-- Boeing Aircraft Company, Seattle, Washington
-- Frontier Technology, Inc., Santa Barbara, California
-- GE Aircraft Engines, Cincinnati, Ohio
-- McDonnell-Douglas Aerospace, Long Beach, California
-- McDonnell Aircraft Company, St. Louis, Missouri
-- RAND Corporation, Santa Monica, California
-- Sargent-Fletcher Company, El Monte, California
MAJOR CONTRIBUTORS TO THIS REPORT
========================================================== Appendix IV
NATIONAL SECURITY AND
INTERNATIONAL AFFAIRS DIVISION
WASHINGTON, D.C.
William C. Meredith, Assistant Director
Tim F. Stone, Evaluator-in-Charge
Martha J. Dey, Evaluator
Kenneth W. Newell, Evaluator
Nancy L. Ragsdale, Evaluator (Communications Analyst)
*** End of document. ***
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