GAO

United States General Accounting Office

Report to Congressional Committees

March 1999 F-22 AIRCRAFT

Issues in Achieving 

Engineering and 

Manufacturing 

Development Goals

GAO/NSIAD-99-55

United States

General Accounting Office

Washington, D.C. 20548 Letr

Page 1 GAO/NSIAD-99-55 F-22 Aircraft

GAO

National Security and

International Affairs Division Letr

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March 15, 1999

Congressional Committees

As required by the National Defense Authorization Act for Fiscal Year 1998 

(P.L. 105-85), we reviewed the Air Force’s F-22 engineering and 

manufacturing development (EMD) program. This report, an update to a 

report we issued last year,1

 presents our conclusions regarding whether the 

Air Force is likely to complete the EMD program without exceeding the 

cost limitation established by the act. The act also requires us to certify 

whether we had access to sufficient information to make informed 

judgments on matters covered by this report.

Results in Brief The Air Force estimates it can complete F-22 EMD within the cost 

limitation. However, during much of 1998, the F-22 contractor cost and 

schedule plans, as defined in 1997, were not fully accomplished. Costs 

exceeded the budgets established to accomplish planned work, and work 

planned was not always completed on schedule. The Air Force viewed the 

potential for further cost growth as a threat to completing EMD within the 

cost limitation. Although the Air Force devised ways to avoid and reduce 

costs, we question whether EMD, as planned, can be completed within the 

cost limitation. Our conclusion is based on the following:

• Cost reviews by the Air Force and the contractors in 1998 identified a 

potential program cost growth of $482 million that, if not addressed, 

could increase program costs above the cost limitation of 

$18.939 billion. Air Force and contractor plans to address this potential 

cost growth have not all been finalized. These plans include eliminating 

some planned EMD activities. Further, unless the plans are successful, 

additional measures will be necessary to reduce costs.

• The contractor has notified the Air Force that F-22 EMD program costs 

may increase if sales of C-130J aircraft, which are manufactured in the 

same plant as the F-22, are lower than anticipated because the F-22 

program will have to absorb a higher share of the plant’s overhead costs.

• Deliveries and first flights of the next four flight-test aircraft are 

expected to be late, reducing flight-testing time available before planned 

EMD completion. Unless the Air Force can successfully compress or 

1

F-22 Aircraft: Progress in Achieving Engineering and Manufacturing Development Goals

(GAO/NSIAD-98-67, Mar. 10, 1998).
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reduce the remaining flight tests to complete EMD as scheduled, EMD 

costs will increase.

• There have been delays in developing the F-22’s integrated avionics2

systems, and the schedule for completing avionics development appears 

unrealistic. If avionics development requires an extension of EMD, 

additional costs will be incurred.

The Air Force currently estimates that the F-22 will meet or exceed all its 

required performance parameters. The estimates are based on computer 

simulations, studies, and flight-test data. The Air Force expects additional 

flight testing to confirm the estimates. As of December 1998, the Air Force 

had completed about 200 flight-test hours and the selected performance 

demonstrations and events required by the Under Secretary of Defense for 

Acquisition and Technology before F-22 production activities begin. In 

December 1998, the Secretary of Defense submitted a report about F-22 

testing and production risks to the Congress, and the Air Force awarded a 

contract to initiate production activities.

The Air Force and the contractors gave us access to sufficient information 

to make informed judgments on the matters covered in this report.

Background The F-22 is an air superiority aircraft with advanced technology features, 

including integrated avionics. The objectives of the F-22 EMD program, 

which began in 1991, are to (1) design, fabricate, test, and deliver 9 F-22 

flight-test vehicles, 2 ground-test vehicles, and 26 flight-qualified engines; 

(2) design, fabricate, integrate, and test the avionics suite; and (3) design, 

develop, and test the support and training systems. The F-22 is being 

developed under cost-type contracts with Lockheed Martin Corporation 

(for the aircraft) and Pratt & Whitney Corporation (for the engines).

Concerned about the growing costs of the F-22 program, the Assistant 

Secretary of the Air Force for Acquisition in June 1996 established the Joint 

Estimating Team (JET) to estimate the most probable cost of the F-22 EMD 

and production programs. The team consisted of personnel from the Air 

Force, the Department of Defense (DOD), and private industry.

2

F-22 avionics are expected to be much more advanced than those of previous fighter aircraft. A 

common computer, rather than multiple computers, will receive, process, and display information to 

minimize the pilot’s workload and provide previously unmatched awareness of potential threats and 

targets.
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The JET concluded in 1997 that additional time would be required to 

complete EMD and estimated that EMD costs would increase to 

$18.688 billion. The JET recommended several changes to the program’s 

schedule, including slower manufacturing for a more efficient transition 

from development to low-rate initial production and an additional 

12 months to complete avionics development. The JET did not recommend 

changing F-22 performance goals. The Air Force and the Under Secretary 

of Defense for Acquisition and Technology generally adopted the JET’s 

recommendations3

 to extend the F-22 EMD schedule, including the dates 

for accomplishing interim events and completing EMD. We used the cost 

and schedule plans established in 1997 as a result of the JET study as an 

analytical baseline to assess whether cost and schedule goals for F-22 EMD 

are being met.

The National Defense Authorization Act for Fiscal Year 1998 established a 

cost limitation of $18.688 billion (an amount that mirrored the JET 

estimate) for the F-22 EMD program and $43.4 billion for the F-22 

production program. The act instructed the Secretary of the Air Force to 

adjust the cost limitations for the amounts of increases or decreases in 

costs attributable to economic inflation after September 30, 1997, and 

compliance with changes in federal, state, and local laws enacted after 

September 30, 1997. Since then, the Air Force has adjusted the EMD 

program’s cost limitation to $18.939 billion.

In May 1998, the Under Secretary of Defense for Acquisition and 

Technology directed the Secretary of the Air Force to modify the F-22’s 

acquisition strategy. This direction designated the first two aircraft as 

production representative test vehicles and the purchase of six aircraft as 

the first low-rate initial production lot. It also required the Air Force to 

brief the Defense Acquisition Board in November 1998 on the progress 

made toward meeting performance criteria established in the directive. 

The criteria were to 

• initiate flight testing of the second EMD aircraft;

• conduct flight operations on the first two EMD aircraft, including flight 

operations at specified speeds and altitudes, the first air refueling, the 

first supersonic flight, the first flight above 30,000 feet, and the first 

flight above an 18-degree angle of attack;

3

For more information on the JET’s recommendations, see Tactical Aircraft: Restructuring of the Air 

Force F-22 Fighter Program (GAO/NSIAD-97-156, June 4, 1997).
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• complete full ground vibration tests on the first EMD aircraft;

• complete the critical design review for block 2 avionics; and

• complete initial release of the first block of software to the flying test 

bed.4

The Strom Thurmond National Defense Authorization Act for Fiscal 

Year 1999 (P.L. 105-261), prohibited the Air Force from obligating funds for 

advance procurement of the first six production aircraft until the Secretary 

of Defense submitted a report that either

• certified that 433 flight-test hours (about 10 percent of the planned 

flight-test program) were completed or

• identified the number of flight-test hours completed, the reasons for the 

Secretary’s determination that fewer than 433 flight-test hours are 

sufficient to decide to proceed to production, the extent to which the 

Secretary’s determination is consistent with each major aircraft 

acquisition decision made by the Defense Acquisition Board since 

January 1997, the amount of flight testing completed that was or was not 

sufficient to justify a decision to proceed to low-rate initial production 

(applies to major aircraft acquisition programs), and a determination by 

the Secretary that it is more financially advantageous for the 

Department to proceed to production than to delay production until 

completion of 433 hours of flight testing, together with the reasons for 

that determination.

As of December 1998, the Air Force had accepted two flight-test aircraft 

and completed about 200 flight-test hours, about 5 percent of the total 

planned flight-test hours for the EMD program. In December 1998, the 

Secretary of Defense submitted a report to the Congress as required by the 

Strom Thurmond National Defense Authorization Act for Fiscal Year 1999, 

and the Air Force awarded contracts for two production representative test 

aircraft and to initiate production activities for six production aircraft. 

Through fiscal year 1999, the Congress had appropriated about $15.6 billion 

for F-22 EMD, or 82 percent of the cost limitation. About $3.3 billion 

remained to be appropriated.

4

The flying test bed is a Boeing 757 designed to test avionics before they are installed on the EMD 

aircraft.
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Extent to Which the 

F-22 Program Is 

Meeting the Cost Goal 

for the EMD Program

Contractor cost experience and studies in 1998 indicated cost growth 

threatened the Air Force’s ability to complete EMD within the 

$18.939 billion cost limitation. As of January 1999, the Air Force estimated 

that the F-22 EMD program will cost $18.911 billion, $28 million less than 

the cost limitation. However, the Air Force and Lockheed Martin have 

identified potential program cost growth of $482 million. Successful 

implementation of plans to reduce the cost growth is essential if the 

program is to be completed within the cost limitation. A factor the Air 

Force did not consider in its estimate of potential cost growth was the 

possibility that the F-22 program may have to absorb a higher share of the 

manufacturing plant’s overhead costs if the contractor does not sell enough 

C-130J aircraft, which are produced at the same plant as the F-22.

Contractor Costs Exceeded 

Budgets for Planned Work

Lockheed Martin reports to the Air Force monthly concerning its progress 

compared with planned costs and schedules. These reports define the cost 

and schedule variances from the contract plans. Through 1998, Lockheed 

Martin reports showed a worsening trend of costs that exceeded its 

budgets for work that had been completed. For example, through January 

1998, Lockheed Martin reported that costs exceeded its budgets by 

$14.4 million. By June 1998, costs exceeded budgets by $93.3 million.

 Studies Identified 

Additional Potential Cost 

Growth 

In early 1998, because contractor costs were exceeding budgets and 

planned work was behind schedule, Lockheed Martin and the Air Force 

studied the EMD program’s estimated costs and identified potential cost 

growth of $482 million.5

 A Lockheed Martin team identified potential cost 

growth of about $240 million, and an Air Force team identified an 

additional potential cost growth of $242 million. As a result of these 

studies, Lockheed Martin requested in November 1998 that the Air Force 

add $240 million to the EMD contract. Air Force officials advised us, 

however, that the increase may be less than $240 million. The Air Force 

5

Air Force and contractor evaluations indicated potential cost growth of $667 million, which could be 

offset by $185 million in management reserves available in the contract price. The net growth, 

accordingly, is about $482 million.
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plans to reallocate funds within the total program to accommodate the cost 

growth and keep the EMD cost within the congressional limitation.6

The primary causes for the potential cost growth were identified as 

(1) designing, modifying, and manufacturing airframe7 components and 

(2) developing and integrating the avionics. Cost growth for the airframe 

was attributed to problems in manufacturing the castings that attach the 

wing to the aircraft’s body, the aft fuselage, the horizontal tails, and the 

engine air inlets; more manufacturing changes than anticipated; and 

additional required analyses. Avionics development experienced cost 

growth because of problems with the technical complexities of the system 

and the delivery by subcontractors of insufficiently developed software.

Plans to Address Potential 

Cost Growth 

Because cost growth of $482 million would cause the EMD program to 

exceed the cost limitation, the Air Force has developed plans to reduce 

F-22 EMD costs. Plans call for eliminating and deferring program elements. 

For example, planned actions include

• deferring external weapons testing until after EMD is completed 

($140 million),

• reassessing the effort required to conduct flight testing for use of a 

helmet targeting system and the AIM-9X missile and reducing the 

estimated cost of testing ($110 million),

• reducing contractor laboratory costs for the test program ($100 million),

• reducing other government costs such as special studies ($50 million), 

and

• implementing Lockheed Martin cost reduction plans ($80 million).

According to the Air Force, testing to certify that the F-22 can effectively 

use externally mounted weapons will be deferred until after EMD is 

completed. Regarding the $80 million in potential reductions expected to 

come from Lockheed Martin’s cost reduction plans, the contractor said that 

it had validated only $20 million as firm cost reductions through November 

1998.

6In February 1999, the Air Force stated that additional costs would be incurred because of problems 

manufacturing wings. The Air Force estimated that additional cost growth of $22 million will occur in 

addition to the potential cost growth identified in 1998. As a result, the Air Force will be required to 

identify offsets to remain within the cost limitation.

7

Airframe refers only to the structural part of the aircraft.
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Potential Impact of C-130J 

Sales on Program

The potential cost growth identified by the Air Force and contractor does 

not include the effects that lower than anticipated sales of C-130J cargo 

aircraft by Lockheed Martin may have on F-22 program costs. Lockheed 

Martin, which produces the C-130J and the F-22 in its Marietta, Georgia, 

plant, has notified the Air Force that the F-22 EMD program will have to 

absorb a higher share of the plant’s overhead costs if fewer C-130Js are sold 

than expected. The Air Force has not taken into account the potential 

impact of this cost increase, which could amount to between 

$150-$160 million per year if C-130J production were to cease, according to 

the Defense Contract Management Command in Marietta. DOD officials 

advised us that increased costs would have to be absorbed only partially by 

the F-22 EMD program and that other business may develop. They 

indicated that Lockheed Martin was negotiating with several foreign 

governments for potential sales of C-130J’s.

Extent to Which the 

F-22 Program Is 

Meeting the Schedule 

Goals for the EMD 

Program

The Air Force is not achieving several of the planned events that were 

established in 1997 as a result of the JET review. In particular, planned 

events for producing EMD aircraft and developing avionics were not being 

met through December 1998. One effect of this is that test aircraft are 

being delivered later than planned, thus preventing flight-test activities 

from being completed as planned. In March 1998 we reported that there 

were delays in achieving these milestones.8

Contractor Did Not 

Accomplish Work as 

Scheduled

Through 1998, Lockheed Martin reports showed a worsening trend in the 

accomplishment of its planned work. For example, through January 1998, 

Lockheed Martin reported that it had not completed planned work valued 

at $70.9 million. By June 1998, it reported that the value of planned work 

not accomplished had increased to $111.5 million.

Manufacturing Problems 

Caused Late Deliveries and 

Reduced Flight- and 

Ground-Testing Time

The first two F-22 EMD aircraft were flight-tested through most of 

December 1998. The first aircraft began flight tests about 3 months later 

than planned, but the second aircraft began testing on time. Because of 

manufacturing problems, however, the Air Force estimates that the next 

four flight-test aircraft will be delivered late. Flight testing is expected to 

8

F-22 Aircraft: Progress in Achieving Engineering and Manufacturing Development Goals

(GAO/NSIAD-98-67, Mar. 10, 1998).
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begin between 2 weeks and over 5 months later than was planned in 1997. 

Also, the two ground-test aircraft are expected to start testing 6 to 

8 months later. As a result, the Air Force has 16.9 fewer flight-test months 

available to complete the flight-test program. Air Force officials said they 

have eliminated the impact of this reduced time by making some flight-test 

aircraft available for testing for longer periods than previously planned and 

by deferring some testing until after the EMD program is completed. 

According to the officials, the Air Force is also studying ways to reduce the 

required flight-test hours. If the Air Force plan to revise the flight-test 

schedule is not successful, additional deferments, or deletions will be 

needed to remain within the cost limitation.

Table 1 compares the 1997 scheduled first flight dates with the expected 

first flight dates as of January 1999.

Table 1: Comparison of Schedules for First Flights of EMD Aircraft

aActual date of first flight.

The delays in first flights are being caused by problems in manufacturing 

wings and fuselages. Wings are expected to be delivered later than the 1997 

schedule because of problems with the development and manufacture of 

large titanium castings that attach the wing to the aircraft’s body. As of 

January 1999, the Air Force and the contractor were working to resolve the 

problem. The Air Force expected Lockheed Martin to receive the wings for 

the next four flight-test aircraft and both ground-test articles between

EMD aircraft

 First flight as 

scheduled in 1997

Expected first flight 

as of January 1999

Months of delay in

first flight

4001 May 29, 1997 September 7, 1997a 3.3

4002 July 9, 1998 June 29, 1998a -0.3

4003 June 16, 1999 November 22, 1999 5.2

4004 August 17, 1999 February 3, 2000 5.6

4005 January 11, 2000 March 31, 2000 2.7

4006 May 18, 2000 May 30, 2000 0.4

4007 September 25, 2000 September 25, 2000 0

4008 February 2, 2001 February 2, 2001 0

4009 June 1, 2001 June 1, 2001 0

Total aircraft flight test months of delay 16.9
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2 weeks and over 6 months late.9 The Air Force also expected the aft 

fuselage—the rear aircraft body section—to be delivered late for the next 

four flight-test aircraft and two ground-test articles because of late 

deliveries of parts and welding difficulties caused by the very small 

tolerances allowed when fitting fuselage parts together. Air Force officials 

said they had identified a solution to the welding problem.

Avionics Development Is 

Behind Schedule

Development of avionics systems for the F-22 is behind the 1997 schedule. 

Although radar system development activities have been completed 

generally on schedule, development problems with the communication, 

navigation, and identification and the electronic warfare systems10 have 

caused schedule delays and cost growth in avionics development. 

Lockheed Martin and the Air Force have included these cost increases in 

their estimates of potential cost growth.

Because of these problems, the Air Force developed a new avionics 

schedule in August 1998, allocating more time to complete the first two 

major avionics segments, known as blocks 1 and 2.11 The subcontractors 

for both systems have had problems integrating the various modules and 

sections of the software, so the process is taking longer than expected. 

Several communication, navigation, and identification sensors failed 

testing and have required further development time and effort. Electronic 

warfare hardware problems have been reportedly caused by problems such 

as faulty designs of some sections and late supplier deliveries. 

Furthermore, officials at Boeing Military Aircraft, a subcontractor that 

operates a key avionics integration laboratory, told us they have been 

receiving late deliveries of software that is insufficiently developed. This 

has added to the time and effort needed to integrate the avionics software.

9

In February 1999, the Air Force stated that wings for the third through the sixth test aircraft will be 

delayed 10 to 15 weeks more than anticipated by the revised schedule. They also said they were 

pursuing mitigation actions to avoid further delays in first flights.

10The communication, navigation, and identification system integrates these three functions to give 

pilots greater awareness of the surrounding situation. The electronic warfare system warns the pilot of 

air or ground radar and missile threats and provides countermeasures.

11Blocks 1, 2, 3S, 3, and 3.1 are each designed to have increased capability over the previous block. The 

last phase of development for each block begins when it is placed on the aircraft for testing.
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Revised Avionics Schedule 

Appears Unrealistic

The Air Force’s August 1998 revised schedule postponed the planned 

completion dates for blocks 1 and 2 but did not change the completion 

dates for subsequent blocks 3 and 3.1,12 even though the majority of initial 

software development tasks related to these last two segments have been 

delayed between 1 and 18 months. In 1997, the JET had concluded that 

avionics development could take as much as 12 months more than planned 

because of delays in all four avionics blocks (1, 2, 3, and 3.1).

Even though blocks 1 and 2 are behind schedule and will probably be 

completed later than planned in 1997, the revised schedule shows avionics 

blocks 3 and 3.1 being completed over 5 months before the completion 

dates that the JET considered realistic in 1997. If blocks 3 and 3.1 take 

longer than planned to be completed under the revised schedule, additional 

costs will be incurred.

Significance of Avionics 

Flight Testing

Integrated avionics is a critical technology advancement for the F-22, and 

substantial flight testing is planned to demonstrate and evaluate its 

capability. The Air Force has planned a substantially higher number of 

avionics flight-test hours in the F-22 program than in previous fighter 

programs. Table 2 compares F-22 avionics flight-test hours to those of 

other fighter programs.

12The revised schedule also adds block 3S between blocks 2 and 3. In adding this block, the Air Force 

moved some block 3 activities ahead for earlier evaluation. This did not, however, change the planned 

completion date for block 3 activities.
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Table 2: Avionics Flight-Test Hours Planned for the F-22 and Completed by Other 

Fighter Aircraft Programs

Extent to Which the 

F-22 Program Is 

Meeting the 

Performance Goals for 

the EMD Program

In December 1998, the Air Force estimated that by the end of the EMD 

program, the F-22 would meet or exceed the goals for the major 

performance parameters. These include 10 parameters on which the Air 

Force reports regularly to DOD and 2 additional performance features we 

reviewed that relate to other critical characteristics of the F-22. The Air 

Force performance estimates were based on flight-test data, computer 

models, ground tests, and analyses.

As we reported last year, we reviewed 2 additional features—situational 

awareness and low observability—that are not among the 10 major 

performance parameters but that both the Air Force and we consider 

critical for the aircraft’s ability to operate as intended. We are therefore 

reporting on the Air Force’s progress in developing these two features. 

Greater situational awareness improves response time to threats, 

increasing the lethality and survivability of the aircraft, while the aircraft’s 

low observable, or stealth, features allow it to evade detection by enemy 

aircraft and surface-to-air missiles.

The 10 parameters and 2 additional features, shown in table 3, are 

described in detail in appendix I. Table 3 shows the goal for each 

parameter, the estimated performance achieved for each parameter as of 

December 1998, and the Air Force’s current estimate of the performance 

each parameter is expected to achieve by the end of the EMD program. 

Most of the goals and related performance information are classified and 

are therefore shown as percentages rather than numbers. 

Aircraft type Number of test aircraft Avionics flight hours

F-14 4 1,168

F-15 3 819

F-16 1 488

F-18 1 591

F-22 6 1,574
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Table 3: Estimates of Performance for Selected Parameters and for Additional 

Features

aThese goals are not acquisition program baseline numbers. We assigned a value of 100 percent to 

evaluate the features.

Initial Production Activities 

Approved

The Air Force accomplished the test events required by the Under 

Secretary of Defense and achieved about 200 hours of flight testing through 

December 1998. The Air Force briefed the Under Secretary on the results of 

the accomplishments on December 17, 1998. On December 23, 1998, the 

Secretary of Defense reported to the Congress that the F-22 program was 

meeting its objectives and that the risk of producing two production 

representative test aircraft and obligating advance procurement funds for 

the first six production aircraft was acceptable. The Under Secretary 

approved award of the contracts for the two production representative test 

aircraft and the advance procurement for the first six production aircraft.

Key performance 

parameters

Goal (acquisition 

program baseline)

Estimated 

performance 12/98

Estimate at EMD 

completion

Supercruise 100% 115% 115%

Acceleration 100% 115% 115%

Maneuverability 100% 104% 104%

Airlift support

(C-141 equivalents)

8 7.7 7.7

Sortie generation 

rate

100% 100% 100%

Radar cross section

(front sector only)

100% Favorable Favorable

Mean time between

maintenance (hours)

3.0 3.1 3.1

Payload (missiles) 4 medium range

2 short range

6 medium range

2 short range

6 medium range

2 short range

Combat radius 100% 124% 124%

Radar detection 

range

100% 117% 117%

Additional features 

reviewed by GAO Goala Estimated 

performance to date

Current estimate at 

EMD completion

Situational 

awareness

100% Favorable Favorable

Low observability 100% Favorable Favorable
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Conclusions It is unlikely that the Air Force will be able to complete the F-22 EMD 

program, as planned, within the cost limitation set by the National Defense 

Authorization Act for Fiscal Year 1998. Our conclusion is based on 

incomplete Air Force cost reduction plans, the potential for increased 

overhead costs if C-130J sales are lower than expected, late deliveries and 

first flights of EMD aircraft, reduced flight-test months, schedule delays in 

developing avionics, and a revised avionics schedule that is not realistic.

The Air Force has revised its avionics development schedule by postponing 

dates for early development activities but not for later tasks. It has thus 

compressed the schedule in a way that may not be realistic, especially 

considering the delays experienced so far and the high number of avionics 

flight-test hours planned. If it takes longer to complete avionics 

development than planned, additional costs will be incurred or actions will 

be necessary to address these costs.

The Air Force is estimating that the F-22 will meet or exceed all its required 

performance parameters. Through December 1998, about 5 percent of the 

flight-test program had been completed to verify these estimates.

Recommendations We recommend that the Secretary of Defense direct the Secretary of the Air 

Force to formulate a more realistic avionics development schedule. We 

recommend that in doing so, the Secretary consider the progress to date, 

the JET’s avionics schedule, and the impact a more realistic schedule 

would have on the EMD program’s estimated cost.

We also recommend that the Secretary of Defense evaluate how decisions 

regarding C-130J production are likely to impact F-22 EMD and assess the 

Air Force’s ability to negate additional overhead costs that may be 

allocated to F-22 EMD.

Agency Comments and 

Our Evaluation

DOD agreed that avionics development and integration is a challenging 

area for the F-22 program and that reduced quantities of C-130J aircraft 

could have a cost impact on the F-22 EMD program.

DOD did not agree that the Secretary of Defense should, at this time, direct 

the Secretary of the Air Force to formulate a more realistic avionics 
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schedule. DOD officials said the Office of the Under Secretary of Defense 

and the Air Force are both aware that schedule pressures resulting from 

emphasis on block 1 avionics will have an impact on development and 

integration of later software blocks. Because the Office of the Under 

Secretary of Defense is aware of potential impacts and is monitoring Air 

Force efforts to mitigate any further schedule impacts, DOD officials 

believe it is unnecessary at this time for DOD to issue further guidance to 

the Air Force about the need to keep the F-22 program on schedule and 

within available funding.

We believe DOD needs to ensure that a realistic avionics development 

schedule is formulated and that DOD is aware of any subsequent impact on 

the program schedule or estimated program cost. We continue to believe 

the recommendation is valid, although we understand that the intent of the 

recommendation may be achievable without issuing formal guidance to the 

Secretary of the Air Force.

DOD partially agreed with our recommendation to evaluate how decisions 

regarding C-130J production are likely to impact the F-22 EMD program 

and assess the Air Force’s ability to nullify additional overhead costs that 

may be allocated to the F-22 EMD program. DOD agreed that a significant 

change to previously anticipated C-130J production volume would have an 

adverse impact on the F-22 program. Until a specific C-130J buy profile is 

available and overhead rates associated with that profile are calculated, 

DOD said it would be unable to determine the specific impact on the F-22 

program. DOD also said that programs at Lockheed Martin other than the 

C-130J could impact the F-22 EMD program.

DOD said its ability to nullify/offset additional overhead costs is limited 

only by the number of cost reduction plans that can be generated, funded, 

and successfully implemented. DOD said the Air Force and Lockheed 

Martin are continually searching for opportunities to reduce the cost of the 

F-22 program.

We continue to believe that the Secretary of Defense should assess how 

changes in Lockheed Martin’s overall business base would affect the F-22 

EMD program. Because the Air Force estimates the F-22 EMD program is 

near its cost limitation, any significant impact as a result of changes in 

Lockheed Martin’s business base could require the Air Force to identify 

mitigation actions to remain within the cost limitation. Therefore, we
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believe our recommendation is still appropriate, as the assessment must be 

completed in time for the Air Force to act on its results.

DOD’s comments are included in appendix III of this report.

We are sending copies of this report to the Secretaries of Defense and the 

Air Force and the Director, Office of Management and Budget. Copies will 

also be made available to others on request.

Please contact me at (202) 512-4841 if you or your staff have any questions 

concerning this report. Major contributors to this report are listed in 

appendix IV.

Louis J. Rodrigues

Director, Defense Acquisitions Issues
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List of Congressional Committees

The Honorable John W. Warner

Chairman

The Honorable Carl Levin

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 D. Spence

Chairman

The Honorable Ike Skelton

Ranking Minority Member

Committee on Armed Services

House of Representatives

The Honorable Jerry Lewis

Chairman

The Honorable John P. Murtha

Ranking Minority Member

Subcommittee on Defense

Committee on Appropriations

House of Representatives
Page 17 GAO/NSIAD-99-55 F-22 Aircraft

Contents

Letter 1

Appendix I

F-22 Performance 

Parameters

19

Appendix II

Objectives, Scope, and 

Methodology

24

Appendix III

Comments From the 

Department of Defense

26

Appendix IV

Major Contributors to 

This Report

30

Related GAO Products 32

Tables Table 1: Comparison of Schedules for First Flights of EMD Aircraft 8

Table 2: Avionics Flight-Test Hours Planned for the F-22 and

Completed by Other Fighter Aircraft Programs 11

Table 3: Estimates of Performance for Selected Parameters and for 

Additional Features 12

Table I.1: F-22 Performance Parameters and Major Subparameters 23
Page 18 GAO/NSIAD-99-55 F-22 Aircraft

Abbreviations

DOD Department of Defense

EMD engineering and manufacturing development

JET Joint Estimating Team

RCS radar cross section
Page 19 GAO/NSIAD-99-55 F-22 Aircraft

Appendix I

F-22 Performance Parameters ApenIxdi

Supercruise Supercruise is the aircraft’s ability to sustain supersonic (greater than 

mach 1)1 speed without using its afterburners. Supercruise saves fuel and 

helps reduce the aircraft’s infrared signature, thus making the F-22 harder 

for the enemy to detect. The goal for the F-22 is to supercruise at a speed 

considerably greater than mach 1 in a stable, level flight at an altitude of 

40,000 feet. The Air Force estimates the F-22 will exceed the supercruise 

goal by about 15 percent. This estimate was determined through an 

analysis of computer models and flight testing completed so far. The 

computer models use data such as the engines’ thrust and fuel flow 

characteristics. Flight testing of the aircraft propulsion characteristics 

began in 1998 and is scheduled to continue into the second quarter of 2000.

Acceleration Acceleration is a key parameter because the F-22 must fly faster than 

enemy aircraft and exit an area quickly after it employs air-to-air or 

air-to-ground munitions. The acceleration parameter refers to the amount 

of time it takes the aircraft to go from 0.8 mach to 1.5 mach speed at an 

altitude of 30,000 feet. The Air Force estimates that the F-22 will exceed its 

acceleration goal. This estimate was determined through an analysis of 

computer models, propulsion ground testing, and flight testing. Flight 

testing of the aircraft’s propulsion characteristics began in 1998 and is 

scheduled to continue into the second quarter of 2000.

Maneuverability Maneuverability is the maximum force the aircraft can generate while 

turning at 0.9 mach speed at an altitude of 30,000 feet without losing speed 

or altitude. Many additional measures of aircraft maneuverability exist, but 

the Air Force has determined that this measurement is the most 

appropriate to demonstrate the F-22’s overall maneuverability under key 

flight conditions. The Air Force estimates the F-22 will exceed its 

maneuverability goal by 4 percent. The estimate was determined through 

an analysis of computer models with data on the major subparameters 

affecting maneuverability and flight testing. Flight performance testing 

began in 1998 and is scheduled to end in the third quarter of 2001.

1

The ratio of the speed of the aircraft to the speed of sound. Mach 1 is about 738 miles per hour. 
Appendix I

F-22 Performance Parameters

Page 20 GAO/NSIAD-99-55 F-22 Aircraft

Airlift Support This parameter measures the number of C-141 transport aircraft 

equivalents required to deploy and maintain a squadron of 24 F-22 aircraft 

for 30 days without resupply. The goal is to be able to provide this support 

with no more than 8 C-141 equivalents, thereby reducing the assets needed 

to deploy and the deployment costs. The Air Force estimates the F-22 will 

require less than 8 C-141 equivalents. A squadron of F-15 aircraft requires 

19 C-141 equivalents. The F-22 estimate will not be verified until a mobility 

demonstration takes place in 2004, when the 24th production aircraft is 

scheduled to be delivered.

Sortie Generation Rate Sortie generation rate is the average number of sorties or missions that can 

be flown per aircraft per day in the first 6 days of a conflict. This parameter 

measures the degree to which the F-22 will be available during the first few 

days of a conflict to achieve and maintain air superiority. The Air Force 

estimates the F-22 will meet the sortie generation rate goal. This estimate 

was based on the results of a computer model using data on maintenance 

characteristics, the availability of support equipment and resources, and 

aircraft maintenance policy. F-22 maintainability demonstrations to verify 

the estimates are scheduled to be completed by 2002.

Radar Cross Section The radar cross section (RCS) parameter essentially refers to how large the 

F-22 appears to enemy radar. The smaller an aircraft’s RCS, the harder it is 

for enemy radar to detect and track the aircraft. A small RCS, along with 

several other factors,2

 contributes to an aircraft’s low observable, or 

stealth, characteristics. Although an aircraft has over 200 RCS 

measurement points, the Air Force considers what is known as the front 

sector RCS—how the aircraft is viewed from the front by enemy radar—the 

most important one. The Air Force estimates that the F-22’s front sector 

RCS will be smaller than its goal. The estimates were based on component 

models that predict the RCS of major components, such as wings and 

engine inlets, and use this data to predict the RCS of an entire aircraft. RCS 

design validation and specification compliance activities are also being 

conducted with a full-scale model of an F-22. This testing will continue into 

1999. In-flight measurements are scheduled to begin in 2000.

2

These include infrared signature, electromagnetic signature, acoustic level, and visibility.
Appendix I

F-22 Performance Parameters

Page 21 GAO/NSIAD-99-55 F-22 Aircraft

Mean Time Between 

Maintenance

Mean time between maintenance is a measure of aircraft reliability defined 

as the total number of aircraft flight hours divided by the total number of 

aircraft maintenance actions in the same period. The F-22’s goal is 3 flight 

hours between maintenance actions by the time the F-22 reaches system 

maturity (100,000 flight hours, in about 2008). The Air Force estimates that 

by the time the F-22 reaches system maturity, it will only require 

maintenance every 3.1 flight hours. The estimate was calculated using a 

reliability computer model that uses factors such as the design of the 

aircraft’s systems and scheduled maintenance activities. Maintenance data 

will be collected from the 500th through the 5,000th hour of flight testing 

throughout the development and operational flight-testing phases to update 

the maintenance estimate. To verify the requirements, data will continue to 

be collected through system maturity.

Payload The payload parameter is the number of medium- and short-range air-to-air 

missiles the F-22 can carry when performing an air superiority mission 

without attacking ground targets. Payload is a key parameter because the 

F-22 is designed to carry missiles in its internal weapons bay, not 

externally. Carrying weapons externally increases an aircraft’s RCS and 

allows easier detection by enemy radar. The Air Force estimates that the 

F-22 will meet the payload goal of carrying six AIM-120C medium-range 

missiles and two AIM-9X short-range missiles internally. Weapons bay 

testing is scheduled for mid-2000 to determine how well the missiles can 

exit the weapons bay when launched.

Combat Radius Combat radius is the number of nautical miles the F-22 must fly to achieve 

its primary mission of air superiority. This requires the F-22 to fly a certain 

distance subsonically (below mach 1 speed) and a certain distance 

supersonically. The Air Force estimates that the F-22 will exceed its 

combat radius goal by 24 percent. According to the Air Force, unfavorable 

estimates for two of three major subparameters—fuel usage and aircraft 

weight—are not unfavorable enough to prevent the F-22 from meeting its 

combat radius goal. Performance flight testing to help compute the 

aircraft’s combat radius performance, as well as other aerodynamic 

capabilities, began in 1998 and will continue into the third quarter of 2001.
Appendix I

F-22 Performance Parameters

Page 22 GAO/NSIAD-99-55 F-22 Aircraft

Radar Detection Range Radar detection range is the number of nautical miles from which the F-22 

should be able to detect potential enemy threats or targets. The aircraft’s 

radar must be able to detect enemy targets that have small radar signatures 

at sufficient distance to ensure that the aircraft can engage the enemy first. 

The Air Force estimates that the F-22’s radar will exceed the established 

goal by 17 percent. This estimate is based on digital simulations, models, 

and flying test-bed flight-test results dedicated to radar testing. Radar 

detection performance is scheduled to be verified against the simulations 

and models in an avionics laboratory until the third quarter of 1999. Actual 

flight testing of the radar in F-22 EMD aircraft is scheduled to begin in 1999 

and continue until at least the second quarter of 2001.

Situational Awareness The situational awareness parameter refers to how the F-22’s sensors and 

avionics systems can make pilots aware of the surrounding situation. The 

planned integration of avionics systems and sensors is meant to 

(1) minimize the pilot’s own management and interpretation of sensors and 

(2) provide previously unmatched awareness of potential threats and 

targets. According to the Air Force’s estimates of the major avionics 

subparameters affecting situational awareness (including radar; electronic 

warfare; and communication, navigation, and identification systems), the 

F-22 will meet the situational awareness goal. Development of the 

integrated avionics, however, is still in the early stages, and the first major 

segment of avionics is not scheduled to be ready for placement on EMD 

flight-test aircraft until April 1999, with four subsequent major segments 

(blocks 2, 3S, 3, and 3.1) still to be completed. Block 3.1 is not scheduled 

for placement on EMD flight-test aircraft until April 2001.

Low Observability Low observability refers to the aircraft’s “stealth,” or its ability to evade 

detection by enemy radar long enough to be the first to detect the enemy 

and fire. Five features contribute to an aircraft’s observability: its RCS and 

its infrared, electromagnetic, visual, and acoustic signatures. The F-22 

does not have a requirement for acoustic signature. The Air Force 

estimates that the F-22 will meet the low-observability performance goals. 

Specification compliance of the most critical feature, RCS, is being 

checked with a full-scale model of an F-22 and will continue into 1999. 

In-flight RCS measurements will begin in 2000 and continue into 2002. 

Flight testing to measure the F-22’s infrared signature is scheduled for the 

third quarter of 1999.
Appendix I

F-22 Performance Parameters

Page 23 GAO/NSIAD-99-55 F-22 Aircraft

Table I.1: F-22 Performance Parameters and Major Subparameters

Performance parameter Major subparameter

Supercruise Engine thrust

Acceleration Aircraft weight

Maneuverability Airframe drag

Airlift support Number of support equipment items

Airlift loads required to deploy support 

equipment

Maintenance manpower required

Sortie generation rate Mean time between maintenance

Maintenance personnel hours/flying hour

Number of support equipment items

Maintenance personnel required

Radar cross section 27 subparameters

Mean time between maintenance Airframe

Avionics

Engines

Payload No subparameters

Combat radius Fuel usage

Aircraft weight

Airframe drag

Radar detection range Range in searching for targets

Range in searching for targets by tracking 

target speed

Time taken to search for targets

Time taken to search for targets by tracking 

target speed

Additional features measured by GAO Major subparameter

Situational awareness Radar function

Electronic warfare function

Communication, navigation, and 

identification functions

Low observability Infrared signature

Electromagnetic emissions signature

Visual signature

Radar cross section
Page 24 GAO/NSIAD-99-55 F-22 Aircraft

Appendix II

Objectives, Scope, and Methodology ApenxIdi

Our objectives were to determine whether the Air Force is likely to 

complete the F-22 EMD program within the congressional cost limitation.

To determine whether the program is likely to meet the cost limitation, we 

examined (1) the extent to which the EMD cost goals are being met; (2) Air 

Force plans to fund the program for the following year; and (3) the 

consistency between the program funding plan and the cost limitation. We 

compared the estimated cost at completion for the prime contracts with 

planned amounts, evaluated cost variances identified in the contractors’ 

cost reporting system, and reviewed the status of initiatives designed to 

avoid cost growth.

To determine whether the program is expected to meet schedule goals, we 

reviewed the program and avionics schedules and discussed potential 

changes to these schedules with F-22 program officials. We also tracked 

progress in the flight-test program. In addition, we evaluated schedule 

variances in the contractors’ performance management system and 

compared planned milestone accomplishment dates with actual dates. We 

tracked technical problems in manufacturing and assembling the EMD 

aircraft. 

To determine whether the program is expected to meet the F-22 

performance goals, we analyzed information on the performance of key 

performance parameters and of those important subparameters that are 

measured. To determine whether estimated performance had changed, we 

compared the Air Force’s current estimate for these parameters with 

previous estimates. 

To evaluate the bases for the Air Force’s current performance estimates, we 

collected information on the goals established for those major performance 

subparameters that are critical components of performance parameters. 

To determine whether the Air Force estimates seemed reasonable, we 

collected and analyzed information on Air Force estimates, as of December 

1998, toward meeting the goals of these subparameters. For example, each 

major subparameter for airlift support--the number of airlift support 

equipment items, the airlift loads needed to transport support equipment 

items, and the maintenance personnel required for a squadron of 

F-22s--has its own performance goal, just as the overall parameter has a 

performance goal. The performance parameters and their associated 

subparameters are shown in table I.1.
Appendix II

Objectives, Scope, and Methodology

Page 25 GAO/NSIAD-99-55 F-22 Aircraft

In performing our work, we obtained information and interviewed officials 

from the Office of the Secretary of Defense, Washington D.C.; the F-22 

System Program Office, Wright-Patterson Air Force Base, Ohio; the 

Defense Contract Management Command, Marietta, Georgia; Lockheed 

Martin Aeronautical Systems, Marietta, Georgia; Lockheed Martin Tactical 

Aircraft Systems, Fort Worth, Texas; and Boeing Military Aircraft, Seattle, 

Washington. We performed our work from April 1998 through March 1999 

in accordance with generally accepted government auditing standards.
Page 26 GAO/NSIAD-99-55 F-22 Aircraft

Appendix III

Comments From the Department of Defense ApenIxdi
Appendix III

Comments From the Department of Defense

Page 27 GAO/NSIAD-99-55 F-22 Aircraft
Appendix III

Comments From the Department of Defense

Page 28 GAO/NSIAD-99-55 F-22 Aircraft

Now on p. 13.
Appendix III

Comments From the Department of Defense

Page 29 GAO/NSIAD-99-55 F-22 Aircraft

Now on p. 13.
Page 30 GAO/NSIAD-99-55 F-22 Aircraft

Appendix IV

Major Contributors to This Report ApeVnxIdi

National Security and

International Affairs

Division, Washington, 

D.C.

David E. Cooper

Robert D. Murphy

Atlanta Field Office Christopher T. Brannon

Chicago Field Office Leonard L. Benson

Edward R. Browning

Don M. Springman

Office of the General

Counsel, Washington, 

D.C.

William T. Woods
Page 31 GAO/NSIAD-99-55 F-22 Aircraft
Page 32 GAO/NSIAD-99-55 F-22 Aircraft

Related GAO Products

F-22 Aircraft: Progress of the Engineering and Manufacturing Program

(GAO/T-NSIAD-98-137, Mar. 25, 1998).

F-22 Aircraft: Progress in Achieving Engineering and Manufacturing

Development Goals (GAO/NSIAD-98-67, Mar. 10, 1998).

Tactical Aircraft: Restructuring of the Air Force F-22 Fighter Program

(GAO/NSIAD-97-156, June 4, 1997).

Defense Aircraft Investments: Major Program Commitments Based on

Optimistic Budget Projections (GAO/T-NSIAD-97-103, Mar. 5, 1997).

F-22 Restructuring (GAO/NSIAD-97-100R, Feb. 28, 1997).

Tactical Aircraft: Concurrency in Development and Production of F-22

Aircraft Should Be Reduced (GAO/NSIAD-95-59, Apr. 19, 1995).

Air Force F-22 Embedded Computers (GAO/AIMD-94-177R, Sept. 20, 1994).

Tactical Aircraft: F-15 Replacement Issues (GAO/T-NSIAD-94-176, May 5, 

1994).

Tactical Aircraft: F-15 Replacement Is Premature as Currently Planned

(GAO/NSIAD-94-118, March 25, 1994).

Aircraft Development: Reasons for Recent Cost Growth in the Advanced

Tactical Fighter Program (GAO/NSIAD-91-138, Feb. 1, 1991).

Aircraft Development: Navy’s Participation in Air Force’s Advanced

Tactical Fighter Program (GAO/NSIAD-90-54, Mar.7, 1990).

Aircraft Development: The Advanced Tactical Fighter’s Costs, Schedule,

and Performance Goals (GAO/NSIAD-88-76, Jan.13, 1988).

Aircraft Procurement: Status and Cost of Air Force Fighter Procurement

(GAO/NSIAD-87-121, Apr. 14, 1987).

DOD Acquisition: Case Study of the Advanced Tactical Fighter Program

(GAO/NSIAD-86-45S-12, Aug. 25, 1986).

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