JOINT STRIKE 

FIGHTER

DOD Actions Needed 

to Further Enhance 

Restructuring and 

Address Affordability 

Risks

Report to Congressional Committees

June 2012

GAO-12-437

United States Government Accountability Office

GAO
United States Government Accountability Office

Highlights of GAO-12-437, a report to 

congressional committees

June 2012

JOINT STRIKE FIGHTER

DOD Actions Needed to Further Enhance 

Restructuring and Address Affordability Risks 

Why GAO Did This Study

The F-35 Lightning II, also known as 

the Joint Strike Fighter (JSF), is the 

Department of Defense’s (DOD) most 

costly and ambitious aircraft 

acquisition, seeking to simultaneously 

develop and field three aircraft variants 

for the Air Force, Navy, Marine Corps, 

and eight international partners. The 

JSF is critical to DOD’s long-term 

recapitalization plans to replace 

hundreds of legacy aircraft. Total U.S. 

investment is now projected at nearly 

$400 billion to develop and acquire 

2,457 aircraft through 2037 and will 

require a long-term, sustained funding 

commitment. The JSF has been 

extensively restructured over the last 2 

years to address relatively poor cost, 

schedule, and performance outcomes.

This report, prepared in response to 

the National Defense Authorization Act 

for Fiscal Year 2010, addresses (1)

JSF program cost and schedule

changes and affordability issues; (2) 

performance objectives, testing results, 

and technical risks; and (3) contract 

costs, concurrency impacts, and 

manufacturing. GAO’s work included 

analyses of a wide range of program 

documents and interviews with 

defense and contractor officials. 

What GAO Recommends

GAO recommends that (1) DOD 

analyze cost and program impacts 

from potentially reduced future funding 

levels and (2) assess the capability 

and challenges facing the JSF’s global 

supply chain. DOD concurred with the

second recommendation and agreed 

with the value of the first, but believed 

its annual budget efforts are sufficient. 

GAO maintains that more robust data 

is needed and could be useful to 

congressional deliberations. 

What GAO Found

Joint Strike Fighter restructuring continued throughout 2011 and into 2012,

adding to cost and schedule. The new program baseline projects total acquisition 

costs of $395.7 billion, an increase of $117.2 billion (42 percent) from the prior 

2007 baseline. Full rate production is now planned for 2019, a delay of 6 years 

from the 2007 baseline. Unit costs per aircraft have doubled since start of 

development in 2001. Critical dates for delivering warfighter requirements remain 

unsettled because of program uncertainties. While the total number of aircraft 

DOD plans to buy has not changed, it has for 3 straight years reduced near-term 

procurement quantities, deferring aircraft and costs to future years. Since 2002, 

the total quantity through 2017 has been reduced by three-fourths, from 1,591 to 

365. Affordability is a key challenge–annual acquisition funding needs average 

about $12.5 billion through 2037 and life-cycle operating and support costs are 

estimated at $1.1 trillion. DOD has not thoroughly analyzed program impacts 

should funding expectations be unmet.

Overall performance in 2011 was mixed as the program achieved 6 of 11 

important objectives. Developmental flight testing gained momentum and is now 

about 21 percent complete with the most challenging tasks still ahead. 

Performance of the short takeoff and vertical landing variant improved this year 

and its “probation” period to fix deficiencies was ended after 1 year with several 

fixes temporary and untested. Developing and integrating the more than 24 

million lines of software code continues to be of concern. Late software releases 

and concurrent work on multiple software blocks have delayed testing and 

training. Development of critical mission systems providing core combat 

capabilities remains behind schedule and risky. To date, only 4 percent of the 

mission systems required for full capability have been verified. Deficiencies with 

the helmet mounted display, integral to mission systems functionality and 

concepts of operation, are most problematic. The autonomic logistics information 

system, integral technology for improving aircraft availability and lowering support 

costs, is not fully developed. 

Most of the instability in the program has been and continues to be the result of 

highly concurrent development, testing, and production activities. Cost overruns 

on the first four annual procurement contracts total more than $1 billion and 

aircraft deliveries are on average more than 1 year late. Program officials said 

the government’s share of the cost growth is $672 million; this adds about $11 

million to the price of each of the 63 aircraft under those contracts. Effectively 

managing the expanding network of global suppliers will be key to improving 

program outcomes, increasing manufacturing throughput, and enabling higher 

production rates. In addition to contract overruns, concurrency costs of at least 

$373 million have been incurred on production aircraft to correct deficiencies 

found in testing. The manufacturing process is still absorbing higher than 

expected number of engineering changes resulting from flight testing, changes 

which are expected to persist at elevated levels into 2019, making it difficult to 

achieve efficient production rates. More design and manufacturing changes are 

expected as testing continues, bringing risks for more contract overruns and 

concurrency costs. Even with the substantial reductions in near-term production 

quantities, DOD still plans to procure 365 aircraft for $69 billion before 

developmental flight tests are completed. 

View GAO-12-437. For more information, 

contact Michael J. Sullivan at (202) 512-4841

or sullivanm@gao.gov.
Page i GAO-12-437 Joint Strike Fighter

Letter 1 

Background 2

Restructuring Reduces Near Term Risk, but Long Term 

Affordability is Challenging 4

Mixed Performance in 2011 Affected by Concurrency and 

Technical Risks 11

Contract Overruns and Concurrency Costs Indicate the Program 

Has Not Yet Stabilized Design and Manufacturing 22

Conclusions 31

Recommendations for Executive Action 33

Agency Comments and our Evaluation 33

Appendix I Scope and Methodology 37

Appendix II Comments from the Department of Defense 39

Appendix III Prior GAO Reports and DOD Responses 42

Appendix IV Budgeted Funding and Procurement Quantities, FY 2011-2017 44

Appendix V Short Takeoff and Vertical Landing Aircraft Probation Period and 

Progress 45

Appendix VI GAO Contact and Staff Acknowledgments 48

Related GAO Products 49

Contents
Page ii GAO-12-437 Joint Strike Fighter

Tables

Table 1: JSF Program Cost and Quantity Estimates over Time 5

Table 2: JSF Program Results for 2011 Objectives 13

Table 3: Procurement Contract Costs as of January 2012 24

Table 4: JSF Procurement Investments and Flight Test Progress 31

Table 5: STOVL Technical Problems Identified for Probation Period 47

Figures 

Figure 1: JSF Aircraft Development Contract Changes 7

Figure 2: Primary Engine Development Contract Changes 7

Figure 3: Changes in Procurement Plans over Time 8

Figure 4: JSF Budgeted Development and Procurement Costs 10

Figure 5: 2011 JSF Flight Test Points Progress 14

Figure 6: Software Growth 19

Figure 7: JSF Concurrency 23

Figure 8: JSF Design Changes Over Time 28

Figure 9: JSF Mean Times between Failure Demonstrated to Date 30
Page iii GAO-12-437 Joint Strike Fighter

Abbreviations

ALIS Autonomic Logistics Information System

CAPE Cost Assessment and Program Evaluation

CTOL conventional takeoff and landing

CV carrier variant 

DCMA Defense Contract Management Agency

DOD Department of Defense

DOT&E Director, Operational Test and Evaluation

DT development testing

JSF Joint Strike Fighter

LRIP low rate initial production

OSD Office of the Secretary of Defense

SDD system development and demonstration

STOVL short takeoff and vertical landing

This is a work of the U.S. government and is not subject to copyright protection in the 

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Page 1 GAO-12-437 Joint Strike Fighter

United States Government Accountability Office

Washington, DC 20548

June 14, 2012

Congressional Committees

The F-35 Lightning II, also known as the Joint Strike Fighter (JSF), is the 

Department of Defense’s (DOD) most costly and ambitious aircraft 

acquisition, seeking to simultaneously develop and field three aircraft 

variants for the Air Force, Navy, Marine Corps, and eight international 

partners. The JSF is critical to DOD’s long-term recapitalization plans as it 

is intended to replace hundreds of legacy fighters and strike aircraft. Total 

U.S. investment in the JSF will be substantial—approaching $400 billion 

to develop and acquire 2,457 aircraft over several decades—and will 

require a long-term sustained funding commitment. Over the last 2 years, 

the JSF program has been extensively restructured to address relatively 

poor cost, schedule, and performance outcomes.

We have reported on JSF issues for a number of years.1 A recurring 

theme in our body of work since 2005 has been a concern about the 

substantial concurrency, or overlap, of JSF development, test, and 

production activities and the heightened risk it poses to achieving good 

program outcomes. The effects of concurrency became apparent in 2011 

as the JSF program incurred an estimated $373 million in additional costs 

to retrofit already-procured aircraft to correct deficiencies discovered 

during testing. Our prior reports have also made numerous 

recommendations for reducing risks and improving chances for 

successful outcomes; DOD has taken actions on these recommendations 

to varying degrees. Appendix III summarizes our major prior reports, 

DOD’s responses, and subsequent actions. In April 2011, we reported 

that the department’s restructuring actions should lead to more 

achievable and predictable outcomes, albeit at higher costs and with 

extended times to test and deliver capabilities to the warfighter.2

 

1 See related GAO products at the end of this report .

The 

report also identified continuing issues concerning affordability risks (both 

for acquiring JSF aircraft and supporting them over the life-cycle), delays 

in software development, a continued high rate of design changes, and 

immature manufacturing processes.

2 GAO, Joint Strike Fighter: Restructuring Places Program on Firmer Footing, but 

Progress Still Lags, GAO-11-325 (Washington, D.C.: Apr. 7, 2011).

 
 

Page 2 GAO-12-437 Joint Strike Fighter

The National Defense Authorization Act for Fiscal Year 20103 requires 

GAO to review the JSF program annually for 6 years. In this report, we 

address (1) program cost and schedule changes and their implications on 

affordability; (2) performance testing results and technical risks; and (3) 

contract cost performance, concurrency impacts, and design and 

manufacturing maturity. This report also includes additional information 

on the “probation period” and performance of the short takeoff and 

vertical landing (STOVL) variant as requested by the Senate Armed 

Services Committee. To conduct this work, we evaluated DOD’s 

restructuring actions and impacts on the program, tracked cost and 

schedule changes, and determined factors driving the changes. We 

reviewed program status reports, manufacturing data, test plans, and 

internal DOD analyses. We discussed results to date and future plans to 

complete JSF development and move further into procurement with DOD, 

JSF, and contractor officials. We toured aircraft and engine manufacturing 

plants, obtained production and supply performance indicators, and 

discussed improvements underway with contractors and DOD plant 

representatives. Appendix I contains a more detailed description of our 

scope and methodology. We conducted this performance audit from June 

2011 to June 2012 in accordance with generally accepted government 

auditing standards. Those standards required that we plan and perform 

the audit to obtain sufficient, appropriate evidence to provide a 

reasonable basis for our findings and conclusions based on our audit 

objectives. We believe that evidence obtained provides a reasonable 

basis for our findings and conclusions based on our audit objectives.

The JSF is a joint, multinational acquisition to develop and field an 

affordable, highly common family of next generation strike fighter aircraft 

for the United States Air Force, Navy, Marine Corps, and eight 

international partners.4 The JSF is a single-seat, single engine aircraft 

incorporating low-observable (stealth) technologies, defensive avionics, 

advanced sensor fusion,5

 

3 Pub. L. No. 111-84, § 244 (2009). 

internal and external weapons, and advanced 

4 The international partners are the United Kingdom, Italy, the Netherlands, Turkey, 

Canada, Australia, Denmark and Norway. These nations are contributing funds for system 

development and have signed agreements to procure aircraft.

5 Sensor fusion is the ability to take information from both multiple on-board and off-board 

aircraft sensors and display the information in an easy-to-use format for the single pilot. 

Background 
 

Page 3 GAO-12-437 Joint Strike Fighter

prognostic maintenance capability. There are three variants. The 

conventional takeoff and landing (CTOL) variant will be an air-to-ground 

replacement for the Air Force’s F-16 Falcon and the A-10 Thunderbolt II 

aircraft, and will complement the F-22A Raptor. The STOVL variant will 

be a multi-role strike fighter to replace the Marine Corps’ F/A-18C/D 

Hornet and AV-8B Harrier aircraft. The carrier-suitable variant (CV) will 

provide the Navy a multi-role, stealthy strike aircraft to complement the 

F/A-18 E/F Super Hornet.

DOD began the JSF program in October 2001 with a highly concurrent, 

aggressive acquisition strategy with substantial overlap between 

development, testing, and production. The program was replanned in 

2004 following weight and performance problems and rebaselined in 

2007 due to cost growth and schedule slips. In February 2010, the 

Secretary of Defense announced another comprehensive restructuring of 

the program due to poor outcomes and continuing problems. This 

restructuring followed an extensive Department-wide review which 

included three independent groups chartered to evaluate program 

execution and resources, manufacturing processes and plans, and 

engine costs and affordability initiatives. DOD provided additional 

resources for testing–funding, time, and flight test assets–and reduced 

near-term procurement by 122 aircraft. As a result of the additional 

funding needed and recognition of higher unit procurement costs, in 

March 2010 the Department declared that the program experienced a 

Nunn-McCurdy breach of the critical cost growth statutory threshold6

 

6 Commonly referred to as Nunn-McCurdy, 10 U.S.C. § 2433 establishes the requirements 

for DOD to submit unit cost reports on major defense acquisition program or designated 

major subprograms. Two measures are tracked against the current and original baseline 

estimates for a program: procurement unit cost (total procurement funds divided by the 

quantity of systems procured) and program acquisition unit cost (total funds for 

development, procurement, and system-specific military construction divided by the 

quantity of systems procured). If a program’s procurement unit cost or acquisition unit cost 

increases by at least 15 percent over the current baseline estimate or at least 30 percent 

over the original baseline estimate, it constitutes a breach of the significant cost growth 

threshold. If a program’s procurement unit cost or acquisition unit cost increases by at 

least 25 percent over the current baseline estimate or at least 50 percent over the original 

baseline estimate, it constitutes a breach of the critical cost growth threshold. Programs 

are required to notify Congress if a Nunn-McCurdy breach is experienced. When a 

program experiences a Nunn-McCurdy breach of the critical cost growth threshold, DOD 

is required to take a number of steps, including reassessing the program and submitting a 

certification to Congress in order to continue the program, in accordance with 10 U.S.C. § 

2433a.

and 

subsequently certified to the Congress in June 2010 that the JSF program 
 

Page 4 GAO-12-437 Joint Strike Fighter

should continue. The program’s approval to enter system development 

was rescinded and efforts commenced to establish a new acquisition 

program baseline. The new JSF program executive officer subsequently 

led a comprehensive technical baseline review. In January 2011, the 

Secretary of Defense announced additional development cost increases, 

further delays, and cut another 124 aircraft through fiscal year 2016.

Restructuring continued throughout 2011 and into 2012, adding to costs 

and extending the schedules for achieving key activities. The 

Department’s restructuring actions have helped reduce near-term risks by 

lowering annual procurement quantities and allowing more time and 

resources for flight testing.

In late March 2012, the Department established a new acquisition 

program baseline and approved the continuation of system development. 

These decisions, critical for program management and oversight, had 

been delayed several times and came 2 years after the Department 

alerted the Congress that the program experienced a breach of the NunnMcCurdy critical cost growth threshold and thus require a new milestone 

approval for system development and a new acquisition program 

baseline. The new JSF baseline projects a total acquisition cost of $395.7 

billion, an increase of $117.2 billion (42 percent) from the prior 2007 

baseline. Table 1 shows changes in cost, quantity, and schedule since 

the start of system development (2001), a major redesign (2004), a 

revised baseline following the program’s Nunn-McCurdy breach of the 

significant cost growth statutory threshold (2007), initial restructuring 

actions after the Nunn-McCurdy breach of the critical cost growth 

statutory threshold (2010), and the new acquisition program baseline 

(2012).

Restructuring 

Reduces Near Term 

Risk, but Long Term 

Affordability is 

Challenging 
 

Page 5 GAO-12-437 Joint Strike Fighter

Table 1: JSF Program Cost and Quantity Estimates over Time 

October 2001 (system

development start)

December 2003 

(2004 replan) 

March 2007 

(approved baseline)

June 2010

(Nunn-McCurdy) 

March 2012

(approved 

baseline)

Expected quantities

Development quantities 14 14 15 14 14

Procurement quantities 

(U.S. only) 2,852 2,443 2,443 2,443 2,443

Total quantities 2,866 2,457 2,458 2,457 2,457

Cost estimates (then-year dollars in billions)

Development $34.4 $44.8 $44.8 $51.8 $55.2

Procurement 196.6 199.8 231.7 325.1 335.7

Military construction 2.0 0.2 2.0 5.6 4.8

Total program acquisition $233.0 $244.8 $278.5 $382.5 $395.7

Unit cost estimates (then-year dollars in millions)

Program acquisition $81 $100 $113 $156 $161

Average procurement 69 82 95 133 137

Estimated delivery and production dates

First production aircraft 

delivery 2008 2009 2010 2010 2011

Initial operational capability 2010-2012 2012-2013 2012-2015 TBD TBD

Full-rate production 2012 2013 2013 2016 2019

Source: GAO analysis of DOD data.

Full rate production is now planned for 2019, a delay of 6 years from the 

2007 baseline. Unit cost estimates continue to increase and have now 

doubled since the start of development. Initial operational capability dates 

for the Air Force, Navy and Marines—the critical dates when the 

warfighter expects the capability promised by the acquisition program to 

be available—have slipped over time and are now unsettled.

The fiscal year 2013 defense budget request and five-year plan supports 

the new approved baseline. Compared to the fiscal year 2012 budget 

plan for the same time period, the 2013 budget plan identifies $369 

million more for JSF development and testing and $14.2 billion less in 

procurement funding for fiscal years 2012 through 2016. Procurement 

funding reflects the reduction of 179 aircraft in annual procurement 

quantities from fiscal year 2013 to fiscal year 2017. Appendix IV 

summarizes the new budget’s development and procurement funding 

requests and aircraft quantities for each service.
 

Page 6 GAO-12-437 Joint Strike Fighter

Taken as a whole, the Department’s restructuring actions have helped 

reduce near term acquisition risks by lowering annual procurement 

quantities and allowing more time and resources for flight testing. 

However, continuing uncertainties about the program and frequently 

changing prognoses make it difficult for the United States and 

international partners to confidently commit to future budgets and 

procurement schedules, while finalizing related plans for basing JSF 

aircraft, developing a support infrastructure, and determining force and 

retirement schedules for legacy aircraft. Over the long haul, affordability is 

a key challenge. Projected annual acquisition funding needs average 

more than $12.5 billion through 2037 and life-cycle operating and support 

costs are estimated at $1.1 trillion.

The new baseline increased cost and extended the schedule for 

completing system development. Development is now expected to cost 

$55.2 billion, an increase of $10.4 billion (23 percent) from the 2007 

baseline. About 80 percent of these funds have been appropriated 

through fiscal year 2011. System development funding is now required 

through fiscal year 2018, 5 more years than the 2007 baseline. Figures 1 

and 2 track cost increases and major events regarding the aircraft and 

engine development contracts, respectively.7

 

7 In addition to the aircraft and engine contract costs shown in figures 1 and 2, the total 

development cost of $55.2 billion in the new baseline includes program management, 

testing, and other government costs of about $15.0 billion.

Development Cost and 

Schedule Changes
 

Page 7 GAO-12-437 Joint Strike Fighter

Figure 1: JSF Aircraft Development Contract Changes

Figure 2: Primary Engine Development Contract Changes
 

Page 8 GAO-12-437 Joint Strike Fighter

The new baseline includes $335.7 billion in procurement funding, an 

increase of $104 billion (45 percent) compared to the 2007 baseline. 

About 6 percent of this total funding requirement has been appropriated 

through fiscal year 2011. Concerned about concurrency risks, DOD, in 

the fiscal year 2013 budget request, reduced planned procurement 

quantities through fiscal year 2017 by 179 aircraft. This marked the third 

time in as many years that near-term procurement quantities had been 

reduced. Combined with other changes since the 2007 revised baseline, 

total JSF procurement quantity has been reduced by 410 aircraft through 

fiscal year 2017. Since the department still plans to eventually acquire the 

full complement of U.S. aircraft—2,443 production jets—the procurement 

costs, fielding schedules, and support requirements for the deferred 

aircraft will be incurred in future years beyond 2017. The new plan also 

stretches the period of planned procurement another two years to 2037. 

Figure 3 shows how planned quantities in the near-term have steadily 

declined over time.

Figure 3: Changes in Procurement Plans over Time

Procurement Cost and 

Quantity Changes
 

Page 9 GAO-12-437 Joint Strike Fighter

With the latest reduction, the program now plans to procure a total of 365 

aircraft through 2017, about one-fourth of the 1,591 aircraft expected in 

the 2002 plan. The ramp rate (annual increases in quantities) for the early 

production years has been significantly flattened over time. Reducing 

near-term procurement quantities lowers concurrency risks because 

fewer aircraft are produced that may later need to be modified to correct 

problems discovered during testing. However, it also means that the 

number of aircraft and associated capabilities that the program committed 

to provide the warfighter will be delivered years later than planned.

Overall program affordability—both in terms of the investment costs to 

acquire the JSF and the continuing costs to operate and maintain it over 

the life-cycle—remains a major challenge. As shown in figure 4, the 

annual funding requirements average more than $12.5 billion through 

2037 and average more than $15 billion annually in the 10-year period 

from fiscal years 2019 through 2028. The Air Force alone needs to 

budget from about $6 to $11 billion per year from fiscal year 2016 through 

2037 for procurement of JSF aircraft. At the same time, the Air Force is 

committed to other big-dollar projects such as the KC-46 tanker and a 

new bomber program.

Affordability Challenges
 

Page 10 GAO-12-437 Joint Strike Fighter

Figure 4: JSF Budgeted Development and Procurement Costs

The long-stated intent that the JSF program would deliver an affordable, 

highly common fifth generation aircraft that could be acquired in large 

numbers is at risk. Continued increases in aircraft prices erode buying 

power and may make it difficult for the U.S. and international partners to 

buy as many aircraft as planned and to do so within the intended 

timeframe. As the JSF program moves forward, unprecedented levels of 

funding will be required during a period of more constrained defense 

funding expectations overall. If future funding is not available at these 

projected levels, the impacts on unit costs and program viability are 

unclear. Program officials have not reported on potential impacts from 

lowered levels of funding.

In addition to the costs for acquiring aircraft, significant concerns and 

questions persist regarding the costs to operate and sustain JSF fleets 

over the coming decades. The most recent estimate projects total United 

States operating and support costs of $1.1 trillion for all three variants

based on a 30-year service life and predicted usage and attrition rates.
 

Page 11 GAO-12-437 Joint Strike Fighter

Defense leadership stated in 2011 that sustainment cost estimates at this 

time were unaffordable and simply unacceptable in the current fiscal 

environment. In March 2012, the Department established affordability 

targets for sustainment as well as production. The sustainment 

affordability target for the Air Force’s CTOL ($35,200 per flight hour) is 

much higher than the current cost for the F-16 it will replace ($22,500 per 

flight hour, both expressed in fiscal year 2012 dollars). Comparative data 

for the Navy’s CV and Marine Corps’ STOVL with the legacy aircraft to be 

replaced was not available. Program officials noted that there are 

substantive differences between legacy and F-35 operating and funding 

assumptions which complicate direct cost comparisons. The program has 

undertaken efforts to address this life-cycle affordability concern.

However, until DOD can demonstrate that the program can perform 

against its cost projections, it will continue to be difficult for the United 

States and international partners to accurately set priorities, establish 

affordable procurement rates, retire aged aircraft, and establish 

supporting infrastructure.

Much of the instability in the JSF program has been and continues to be 

the result of highly concurrent development, testing, and production 

activities. During 2011, overall performance was mixed as the program 

achieved 6 of 11 primary objectives for the year. Developmental flight 

testing gained momentum and had tangible success, but it has a long 

road ahead with testing of the most complex software and advanced 

capabilities still in the future. JSF software development is one of the 

largest and most complex projects in DOD history, providing essential 

capability, but software has grown in size and complexity, and is taking 

longer to complete than expected. Developing, testing, and integrating 

software, mission systems, and logistics systems are critical for 

demonstrating the operational effectiveness and suitability of a fully 

integrated, capable aircraft and pose significant technical risks moving 

forward. Until a fully integrated, capable aircraft is flight tested–planned to 

start in 2015–the program is still very susceptible to discovering costly 

design and technical problems after many aircraft have been fielded.

Mixed Performance in 

2011 Affected by 

Concurrency and 

Technical Risks
 

Page 12 GAO-12-437 Joint Strike Fighter

The JSF program achieved 6 of 11 primary objectives it established for 

2011. Five of the objectives were specific test and training actions tied to 

contractual expectations and award fees, according to program officials. 

The other 6 objectives were associated with cost, schedule, contract 

negotiations, and sustainment. The program successfully met 2 important 

test objectives: the Marine Corps’ short takeoff and vertical landing 

(STOVL) variant accomplished sea trials and the Navy’s carrier variant 

(CV) completed static structural testing. Two other test objectives were 

not met: software was not released to flight test in time and the carrier 

variant did not demonstrate shipboard suitability because of problems 

with the tail hook arrestment system. The program also successfully 

completed objectives related to sustainment design reviews, schedule 

data, manufacturing processes, and cost control, but did not meet a 

training deadline or complete contract negotiations. Table 2 summarizes 

the 2011 objectives and accomplishments.

Program Performance 

Against 2011 Stated 

Objectives Was Mixed
 

Page 13 GAO-12-437 Joint Strike Fighter

Table 2: JSF Program Results for 2011 Objectives

2011 JSF Program Objectives

Objective (Grey shaded objectives 

are contractual objectives)

Objective 

met? Accomplishments

Test

Complete carrier variant static 

structural testing 

Yes Executed planned test conditions for CV (CG-1) variant.

Complete first carrier variant 

ship suitability events 

No Suitability testing was not completed; tail hook did not successfully engage the 

cable during ground testing. 

Release initial Block 2A 

software to flight test 

No Did not complete timely Block 2 software release. Block 2A is flying on surrogate 

aircraft, with initial Block 2A F-35 flights in January 2012 pending a successful Air 

System Test Readiness Review.

Execute short take-off and 

landing variant sea trials on 

amphibious assault ship

Yes Executed F-35B sea trials focused on flying qualities and performance tests, 

vertical landing to designated locations, and external environment effects on the 

ship.

Training/

sustainment

Deliver Block 1 training update 

to Eglin (capability, envelope, 

trainers, autonomic logistics 

information system ) 

No Did not complete Block 1 training update to Eglin Air Force Base. Operations to 

practice and validate training profiles, maintenance procedures, and build maturity 

are expected to begin in early 2012, with a software Block 1A operational utility 

evaluation and declaration of training readiness to follow. Block 1B training will 

follow Block 1A readiness.

Complete sustainment design 

reviews, cost and strategy 

bottoms up

Yes Completed design review of the supply chain management concept for F-35, third 

war game effort, and business case analysis phase 1 for sustainment strategy; 

further developed sustainment baseline; and completed a review of ground rules 

and assumptions to support a revised operations and support cost estimate.

Contract

Complete over target baseline 

negotiations

No Program did not gain agreement on new prime and engine contractor program 

management baselines to complete system development and demonstration or 

negotiate contract modifications to update cost and schedule positions. The 

program is finalizing details to begin negotiations in early 2012.

Negotiate Low Rate Initial

Production (LRIP) 5 production 

contract

No Program did not complete negotiations and sign a definitized LRIP 5 production 

contract. The program executed an undefinitized a

Cost/Schedule

LRIP 5 contract action, which 

included completed negotiations on contract terms and conditions concerning 

concurrency cost sharing. 

Observe LRIP 4 cost control Yes Program observed cost control with LRIP 4 production activities. Projected 

average percent overrun for LRIP 4 aircraft is lower than the previous LRIP buys.

b

Populate prime contractor 

EVMS data with new replanned schedule 

Yes Program office and prime contractor agreed on a new prime contractor system 

development and demonstration program performance measurement baseline, 

loaded the cost/schedule position, and began reporting against the baseline.

Observe prime contractor 

delivering assembled wings 

and forward fuselage to mate 

station on time at reduced cost 

Yes Prime contractor agreed to delivery dates for LRIP 4 wing and forward fuselage; 

kept LRIP 4 average aircraft cost lower than LRIPs 2/3; reduced number of quality 

assurance reports, improved quality, and minimized rework; reduced span times 

without increasing of out-of-station work; and achieved contract target cost.

Source: JSF Program Office Data.

a An undefinitized contract action means any contract action for which the contract terms, 

specifications, or price are not agreed upon before performance is begun under the action. 

Defense Federal Acquisition Regulation Supplement section 217.7401(d). 

b Program officials consider this objective met for the reason stated above. We note that 

the current size of the overrun is considerable and that it could very well change for better 

or worse as this lot is still early in the production process.
 

Page 14 GAO-12-437 Joint Strike Fighter

Development flight testing gained momentum and met or exceeded most 

objectives in its modified test plan for 2011. The program accomplished 

972 test flights in 2011, more than double the flights in 2010. Final 

deliveries of the remaining test aircraft were made in 2011 (with the 

exception of one carrier variant added in restructuring and expected in 

2012) and five production aircraft have been made available to the test 

program. Flight test points8

Figure 5: 2011 JSF Flight Test Points Progress

accomplished in 2011 exceeded the plan 

overall, as shown in figure 5. CTOL flight test points achieved fell short of 

the plan, due to operating limitations and aircraft reliability.

 

8 Flight test points are specific, quantifiable objectives in flight plans that are needed to 

verify aircraft design and performance. 

Development Flight 

Testing Gained Momentum
 

Page 15 GAO-12-437 Joint Strike Fighter

Flight testing during 2011 included the following results:

• Navy’s Carrier Variant: The program successfully accomplished 65 

catapult launches, but problems with the arresting hook prevented 

successful engagement with the cable during ground testing. Analysis 

of test results discovered tail hook design issues that have major 

consequences, according to DOD officials. The tail hook point is being 

redesigned and other aircraft structural modifications may also be 

required. The program must have fixes in place and deficiencies 

resolved in order to accomplish CV ship trials in late 2013. Since the 

carrier variant has just started initial carrier suitability tests, the 

proposed design changes will not be demonstrated until much later in 

developmental testing and could require significant structural changes 

to already-delivered aircraft. According to officials from the office of 

the Director, Operational Test and Evaluation (DOT&E), the program 

is also working to correct a number of other carrier variant 

performance problems such as excessive nose gear oscillations 

during taxi operations, excessive landing gear retraction times, and 

overheating of the electro-hydrostatic actuator systems that power 

flight controls. The program has not yet determined if production 

aircraft will need to be modified to address these issues.

• Air Force’s Conventional Takeoff and Landing Variant: The JSF test 

team flew the planned number of CTOL flights in 2011 but achieved 

about 10 percent fewer flight sciences test points than planned. 

Aircraft operating limitations and inadequate instrumentation impacted 

the ability to complete the planned number of test points. Contributing 

factors included deficiencies in the air vehicle’s air data system as 

well as in-flight data indicating different structural loads than 

predicted. Aircraft reliability and parts shortages also affected the 

number of CTOL flight tests.

• Marine Corps’s Short Take Off and Vertical Landing Variant: The 

STOVL variant performed better than expected in flight tests during 

2011. It increased flight test rates and STOVL-specific mode testing, 

surpassing planned test point progress for the year. Following 

reliability problems and performance issues, the Secretary of Defense 

in January 2011 had placed the STOVL on “probation” for up to two

years, citing technical issues unique to the variant that would add to 

the aircraft’s cost and weight. In January 2012, the Secretary of 

Defense lifted the STOVL probation after one year, citing improved 

performance and completion of the initial sea trials as a basis for the 

decision. The Department concluded that STOVL development, test, 

and production maturity is now comparable to the other two variants. 
 

Page 16 GAO-12-437 Joint Strike Fighter

While several technical issues have been addressed and some 

potential solutions engineered, assessing whether the deficiencies are 

resolved is ongoing and, in some cases, will not be known for years.

According to the program office, two of the five specific problems cited 

are considered to be fixed while the other three have temporary fixes 

in place. (See Appendix V which provides a more detailed 

examination of the STOVL probation, deficiencies addressed, and 

plans for correcting deficiencies.) DOT&E officials reported that 

significant work remains to verify and incorporate modifications to 

correct known STOVL deficiencies and prepare the system for 

operational use. Until the proposed technical solutions have been fully 

tested and demonstrated, it cannot be determined if the technical 

problems have been resolved.

Even with the progress in 2011, most development flight testing, including 

the most challenging, still lies ahead. Through 2011, the flight test 

program had completed 21 percent of the nearly 60,000 planned flight 

test points estimated for the entire program.9

 

9 According to program officials, completion of a test point means that the test point has 

been flown and that flight engineers ruled that the point has met the need. Further 

analysis may be necessary for the test point to be closed out.

Program officials reported 

that flight tests to date have largely demonstrated air worthiness, flying 

qualities, and initial speed, altitude, and maneuvering performance 

requirements. According to JSF test officials, the more complex testing 

such as low altitude flight operations, weapons and mission systems 

integration, and high angle of attack has yet to be done for any variant 

and may result in new discoveries of aircraft deficiencies. Initial 

development flight tests of a fully integrated, capable JSF aircraft to 

demonstrate full mission systems capabilities, weapons delivery, and 

autonomic logistics is not expected until 2015 at the earliest. This will be 

critical for verifying that the JSF aircraft will work as intended and for 

demonstrating that the design is not likely to need costly changes. 

Development flight testing in a production-representative test aircraft and 

in the operational flight environment planned for the JSF is important to 

reducing risk. This actual environment differs from what can be 

demonstrated in the laboratory and has historically identified unexpected 

problems. For example, the F-22A fighter software worked as expected in 

the laboratory, but significant problems were identified in flight tests. 

These problems delayed testing and the delivery of a proven capability to 

the warfighter. Like other major weapon systems acquisitions, the JSF will 
 

Page 17 GAO-12-437 Joint Strike Fighter

be susceptible to discovering costly problems later in development when 

the more complex software and advanced capabilities are integrated and 

flight tested. With most development flight testing still to go, the program 

can expect more changes to aircraft design and continued alterations of 

manufacturing processes.

Initial dedicated operational testing of a fully integrated and capable JSF 

is scheduled to begin in 2017. Initial operational testing is important for 

evaluating the effectiveness and suitability of the JSF in an operationally 

realistic environment. It is a prerequisite for JSF full-rate production 

decision in 2019. The JSF operational test team10

In its 2011 annual report, DOT&E reported many challenges for the JSF 

program due to the high level of concurrency of production, development, 

and test activities. Flight training efforts were delayed because of 

immature aircraft. Durability testing identified structural modifications

needed for production aircraft to meet service life and operational 

requirements. Analysis of the bulkhead crack problem revealed numerous 

other life-limited parts on all three variants. According to DOT&E’s report, 

the most significant of these deficiencies in terms of complexity, aircraft 

downtime, and difficulty in modification required for existing aircraft is the 

forward wing root rib which experienced cracking during CTOL durability 

testing. STOVL variant aircraft are also affected. Production aircraft in the 

first four lots (63 aircraft) will need the modification before these aircraft 

reach their forward root rib operating limits, which program officials 

assessed system 

readiness for initial operational testing and identified several outstanding 

risk items. The test team’s operational assessment concluded that the 

JSF is not on track to meet operational effectiveness or operational 

suitability requirements. The test team’s October 2011 report identified 

deficiencies in the helmet mounted display, night vision capability, aircraft 

handling characteristics, and shortfalls in maneuvering performance. Test 

officials also reported an inadequate logistics system for deployments, 

excessive time for low observable repair and restoration, low reliability, 

and poor maintainability performance. The team’s report noted that many 

of the concerns that drive the program’s readiness for operational test 

and evaluation are also critical path items to meet effectiveness and 

suitability requirements.

 

10 The JSF Operational Test Team consists of members from the Air Force Test and 

Evaluation Center, the Navy’s Operational Test and Evaluation Force, and the United 

Kingdom’s Air Warfare Centre.
 

Page 18 GAO-12-437 Joint Strike Fighter

identified as 574 flight hours for the CTOL and 750 hours for the STOVL. 

DOT&E also found that, although it is early in the program, current 

reliability and maintainability data indicate that more attention is needed in 

these areas to achieve an operationally suitable system. Its report also 

highlighted several discoveries which included deficiencies in the helmet 

mounted display, STOVL door and propulsion problems, limited progress 

in demonstrating mission systems capabilities, and challenges in 

managing weight growth.

Software providing essential JSF capability has grown in size and 

complexity, and is taking longer to complete than expected. Late releases 

of software have delayed testing and training and added costs. Some 

capabilities have been deferred until later in development in order to 

maintain schedule.

The lines of code necessary for the JSF’s capabilities have now grown to

over 24 million—9.5 million on-board the aircraft. (By comparison, JSF 

has about 3 times more on-board software lines of code than the F-22A 

Raptor and 6 times more than the F/A-18 E/F Super Hornet.) This has 

added work and increased the overall complexity of the effort. The 

software on-board the aircraft and needed for operations has grown 37 

percent since the critical design review in 2005. While software growth 

appears to be stabilizing, contractor officials report that almost half of the 

on-board software has yet to complete integration and test—typically the 

most challenging phase of software development. JSF software growth is 

not much different than other recent defense acquisitions, which have 

experienced from 30 to 100 percent growth in software code over time.

However, the sheer number of lines of code for the JSF makes the growth 

a notable cost and schedule challenge. Figure 6 shows increased lines of 

code for both airborne and ground systems.

Software Development and 

Integration Represent 

Significant Risks
 

Page 19 GAO-12-437 Joint Strike Fighter

Figure 6: Software Growth 

JSF software capabilities are developed, integrated, tested, and delivered 

to aircraft in 5 increments or blocks. Software defects, low productivity, 

and concurrent development of successive blocks have created 

inefficiencies, taking longer to fix defects and delaying the demonstration 

of critical capabilities. Delays in developing, integrating, and releasing 

software to the test program have cascading effects hampering flight 

tests, training, and test lab accreditation. While progress has been made, 

a substantial amount of software work remains before the program can 

demonstrate full warfighting capability. Block 0.1, providing flight science 

capabilities for test aircraft, was released about six months late and block 

0.5, providing basic flight systems, was almost two years late, due largely 

to integration problems. Status of the other 3 blocks follows:

• Block 1.0 provides initial training capability and was released to flight 

test three years late when compared to the 2006 plan. More recently, 

it began flight test three months late based on the new plan, and was 

delayed by defects, workload bottlenecks, and security approvals. 

Late delivery of block 1.0 to training resulted in the program missing 
 

Page 20 GAO-12-437 Joint Strike Fighter

one of its key goals for 2011. Block 1.0 was planned to complete 

testing and be delivered to training in 2011. Full block 1.0 flight testing 

was only 25 percent complete at that time and fewer than half of the 

final block 1.0 capabilities (12 of 35) had met full contract verification 

requirements for aircraft delivery, according to officials.

• Block 2.0 provides initial warfighting capability, including weapons 

employment, electronic attack, and interoperability. Its full release to 

testing is now expected in late 2013, over three years later than 

planned in 2006. Development has fallen behind due to integration 

challenges and the reallocation of resources to fix block 1.0. As of 

December 2011, block 2.0 has completed only half of the planned 

schedule, leaving approximately 70 percent of integration work to 

complete.

• Block 3.0

To maintain schedule, the program has deferred some capabilities to later 

blocks. For example, initial air to ground capabilities were deferred from 

block 1.0 to 2.0, and several data fusion elements moved from block 2.0 

to 3.0. Deferring tasks to later phases of the development program adds 

more pressure and costs to future software management efforts. It also 

likely increases the probability of defects being realized later in the 

program when the more complex capabilities in these later blocks are 

already expected to be a substantial technical challenge. Recently, some 

weapons were moved earlier in the plan, from block 3.0 to 2.0, to provide 

more combat capability in earlier production aircraft.

provides the full capability required by the warfighter, 

including full sensor fusion and additional weapons. In its early stage, 

development and integration is slightly behind schedule with 30 

percent of initial block 3.0 having completed the development phase. 

These challenges will continue as the program develops, integrates, 

and tests the increasingly complex mission systems software work 

that lies ahead.

Because software is critical to the delivery of war fighter capabilities and 

presents complex cost, schedule and performance challenges, we 

recommended in our April 2011 report that an independent review of 

software development, integration, and testing–similar to the review of 

manufacturing processes–be undertaken. An initial contractor study was 

recently completed that focused on mission systems’ staffing, 

development, defects, and rework. Program officials are currently 

implementing several improvement initiatives and plan to broaden the 

assessment to off-board software development efforts including logistics 

and training.
 

Page 21 GAO-12-437 Joint Strike Fighter

JSF’s mission systems11

The helmet mounted display in particular continues to have significant 

technical deficiencies that make it less functional than legacy equipment. 

The display is integral to the mission systems architecture, reducing pilot 

workload, and the overall JSF concept of operations—displaying key 

aircraft performance information as well as tactical situational awareness 

and weapons employment information on the pilot’s helmet visor, 

replacing conventional heads-up display systems. Helmet problems 

include integration of the night vision capability, display jitter, and latency 

(or delay) in transmitting sensor data.

and logistics systems are critical to realizing the 

operational and support capabilities expected by the warfighter, but the 

hardware and software for these systems are immature and unproven at 

this time. For example, only 4 percent of mission systems requirements 

planned in system development and demonstration have been verified.

Significant learning and development remains before the program can 

demonstrate mature mission systems software and hardware, not 

expected until block 3.0 is delivered in 2015. The program has 

experienced significant challenges developing and integrating mission 

systems software. Mission systems hardware has also experienced 

several technical challenges, including problems with the radar, 

integrated processor, communication and navigation equipment, and 

electronic warfare capabilities.

12

 

11 Mission systems provide combat effectiveness through next generation sensors with 

fused information from on-board and off-board systems (i.e. Electronic Warfare, 

Communication Navigation Identification, Electro-Optical Target System, Electro-Optical 

Distributed Aperture System, Radar, and Data Links). 

These shortfalls may lead to a 

helmet unable to fully meet warfighter requirements—unsuitable for flight 

tasks and weapon delivery, as well as creating an unmanageable pilot 

workload, and may place limitations on the JSF’s operational 

environment, according to program officials. The program office is 

pursuing a dual path to compensate for the technical issues by 

developing a second, less capable helmet while trying to fix the first 

helmet design; this development effort will cost more than $80 million. 

The selected helmet will not be integrated into the baseline aircraft until 

12 Latency is a perceivable discrepancy or lag that occurs between a physical input (e.g. 

head movement) and the time it takes the computer to recalibrate with a corresponding 

change. This is the result of system delay including the head tracker delay, computer 

graphic delay, and display delay. Display jitter is the undesired shaking of display, making 

symbology unreadable under those conditions. Regarding the JSF, jitter results from 

worse than expected vibrations, known as aircraft buffet. 

Mission Systems and 

Logistics Systems Maturity 

Will Be Key for 

Demonstrating JSF 

Operational Effectiveness 

and Suitability
 

Page 22 GAO-12-437 Joint Strike Fighter

2014 or later, increasing the risks of a major system redesign, retrofits of 

already built aircraft, or changes in concepts of operation.

The Autonomic Logistics Information System (ALIS) is an integral part of 

the JSF system and serves as an information portal to JSF-unique and 

external systems, implements and automates logistics processes, and 

provides decision aids to reduce support resources such as manpower

and spares. The ALIS is key technology aimed at improving and 

streamlining logistics and maintenance functions in order to reduce life 

cycle costs. It is designed to be proactive–recognize problems and initiate 

correct responses automatically. The JSF test team operational 

assessment report concluded that an early release model of ALIS was not 

mature, did not meet operational suitability requirements, and would 

require substantial improvements to achieve sortie generation rates and 

life cycle cost requirements. In particular, the current configuration was 

not adequate for deployed operations–its current weight, environmental 

support, connectivity, and security requirements make it difficult to 

support detachments, operational testing, and forward operations, 

especially vital to the Marine Corps plans. The report noted that there is 

no approved concept or design for this capability, no funding identified, 

and stated a concern that there may be no formal solution prior to Marine 

Corps declaring an initial operating capability. Operational testers also 

identified concerns about data and interoperability with service 

maintenance systems. Program officials have identified deployable ALIS 

as a development-funded effort structured to address the difficulties 

surrounding the deployment of the current ALIS suite of equipment. The 

formal solution is expected to be ready for fielding in 2015.

The program has not yet demonstrated a stable design and 

manufacturing process capable of efficient production. Engineering 

changes are persisting at relatively high rates and additional changes will 

be needed as testing continues. Manufacturing processes and 

performance indicators show some progress, but performance on the first 

four low-rate initial production contracts has not been good. All four have 

experienced cost overruns and late aircraft deliveries. In addition, the 

government is also incurring substantial additional costs to retrofit 

produced aircraft to correct deficiencies discovered in testing. Until 

manufacturing processes are in control and engineering design changes 

resulting from information gained during developmental testing are 

reduced, there is risk of further cost growth. Actions the Department has 

taken to restructure the program have helped, but remaining concurrency 

between flight testing and production continues to put cost and schedule 

Contract Overruns 

and Concurrency 

Costs Indicate the 

Program Has Not Yet 

Stabilized Design and 

Manufacturing 
 

Page 23 GAO-12-437 Joint Strike Fighter

at risk (see figure 7). Even with the substantial reductions in near-term 

procurement quantities, DOD is still investing billions of dollars on 

hundreds of aircraft while flight testing has years to go.

Figure 7: JSF Concurrency

Note: SDD= system development and demonstration; DT = developmental test.

As was the experience with building the development test aircraft, 

manufacturing the production aircraft is costing more and taking longer 

than planned. Cost overruns and delivery slips indicate that 

manufacturing processes, worker learning, quality control, and supplier 

performance are not yet sufficiently mature to handle the volume of work 

scheduled. Cost overruns on each of the first four annual procurement 

contracts are currently projected to total about $1 billion (see table 3).

Cost Overruns and 

Delivery Delays Indicate 

Need to Further Mature 

the Manufacturing Process
 

Page 24 GAO-12-437 Joint Strike Fighter

Table 3: Procurement Contract Costs as of January 2012

Dollars in millions

Contract

Number

of aircraft

Contract

cost at award

Current contract

cost estimate

Cost

increase

Percent

increase

LRIP 1 2 $511.7 $561.5 $49.8 9.7

LRIP 2 12 $2,278.5 $2,607.7 $329.2 14.4

LRIP 3 17 $3,154.2 $3,569.5 $415.3 13.2

LRIP 4 32 $3,458.3 $3,703.3 $245.0 7.1

Total 63 $9,402.7 $10,442.0 $1,039.3 11.1

Source: GAO analysis of DOD data.

Note: LRIP is low rate initial production.

According to program documentation, through the cost sharing provisions 

in these contracts, the government’s share of the total overrun is about 

$672 million. On average, the government is paying an additional $11 

million for each of the 63 aircraft under contract (58 are U.S. aircraft and 5 

are for international partners). There is risk of additional cost overruns 

because all work is not completed. Defense officials reduced the buy 

quantity in the fifth annual procurement contract to help fund these cost 

overruns and additional retrofit costs to fix deficiencies discovered in 

testing.

While Lockheed Martin, the prime contractor, is demonstrating somewhat 

better throughput capacity and showing improved performance indicators, 

the lingering effects of critical parts shortages, out of station work13

The manufacturing effort has a long way to go with thousands of aircraft 

planned for production over the next 25 years. Through fiscal year 2011, 

, and 

quality issues continue to be key cost and schedule drivers on the first 

four production lots. Design modifications to address deficiencies 

discovered in testing, incorporation of bulkhead and wing process 

improvements, and reintroduction of the carrier variant into the 

manufacturing line further impacted production during 2011. Lockheed 

had expected to deliver 31 procurement aircraft by the end of 2011 but 

delivered only nine aircraft. Each was delivered more than 1 year late.

 

13 Out of station work occurs when manufacturing steps are not completed at the 

designated work station and must be finished elsewhere later in production. This is highly 

inefficient, increasing labor hours, causing delays, and sometimes quality problems. 
 

Page 25 GAO-12-437 Joint Strike Fighter

only 6 percent of the total procurement funding needed to complete the 

JSF program had been appropriated. As the rate of production is 

expected to increase substantially starting in 2015, it is vital that the 

contractor achieve an efficient manufacturing process. Several positive 

accomplishments may spur improved future performance. Lockheed 

implemented an improved and comprehensive integrated master 

schedule, loaded the new program data from restructuring, and 

completed a schedule risk assessment, as we recommended several 

years ago.14 Also, Defense Contract Management Agency (DCMA) and 

JSF program officials believe that Lockheed Martin has made a concerted 

effort to improve its earned value management system (EVMS)15

Pratt & Whitney, the engine manufacturer, has delivered 54 production 

engines and 21 lift fans as of early May 2012.

in order 

to comply with federal standards. Initial reviews of the new procedures, 

tools, and training indicate that the company is on track to have its 

revised processes approved by DCMA this year.

16

Going forward, effectively managing the expanding global supplier 

network – which consists of hundreds of suppliers around the world–is 

Like the aircraft system, 

the propulsion system is still under development and the program is 

working to complete testing and fix deficiencies while concurrently 

delivering engines under the initial procurement contracts. The program 

office’s estimated cost for the system development and demonstration of 

the engine has increased by 73 percent, from $4.8 billion to about $8.4 

billion, since the start of development. Engine deliveries continue to miss 

expected contract due dates but still met aircraft need dates. Supplier 

performance problems and design changes are driving late engine 

deliveries. Lift fan system components and processes are driving cost 

and schedule problems.

 

14 GAO-08-388 and GAO-09-303. 

15 The Earned Value Management System is an important tool that can provide objective 

production data, track actual costs to budgets, and project contract costs at completion. 

DOD requires its use by major defense suppliers to facilitate good insight and oversight of 

the expenditure of government dollars, thereby improving both affordability and 

accountability. In 2007, DCMA found that Lockheed was deficient in meeting 19 of 32 

required guidelines, calling into question its ability to manage the escalating costs and 

complex scheduling of the JSF program.

16 Note: The engine contractor has production contracts with the government and the 

engines are provided as government furnished equipment to the JSF prime contractor. 
 

Page 26 GAO-12-437 Joint Strike Fighter

fundamental to meeting production rate and throughput expectations. 

DOD’s Independent Manufacturing Review Team 2009 report identified 

global supply chain management as the most critical challenge for 

meeting production expectations. The cooperative aspect of the supply 

chain provides both benefits and challenges. The international program 

structure is based on a complex set of relationships involving both 

government and industry from the United States and eight other 

countries. Overseas suppliers are playing a major and increasing role in 

JSF manufacturing and logistics. For example, center fuselage and wings 

will be manufactured by Turkish and Italian suppliers, respectively, as 

second sources. In addition to ongoing supplier challenges–parts 

shortages, failed parts, and late deliveries– incorporating international 

suppliers presents other challenges. The program must deal with 

exchange rate fluctuations, disagreements over work shares, and 

technology transfer concerns. To date, the mostly U.S.-based suppliers 

have sometimes struggled to develop critical and complex parts while 

others have had problems with limited production capacity. Lockheed 

Martin has implemented a stricter supplier assessment program to help 

manage supplier performance.

We and some defense offices cautioned the Department years ago about 

the risks posed by the extremely high degree of concurrency, or overlap, 

among the JSF development, testing, and production activities.17

 

17 GAO, Joint Strike Fighter: DOD Plans to Enter Production before Testing Demonstrates 

Acceptable Performance, 

In the 

first four production lots, the U. S. government will incur an estimated 

$373 million in retrofit costs on already-built aircraft to correct deficiencies 

discovered in development testing. This is in addition to the $672 million 

for the government’s share of contract cost overruns. The program office 

projects additional retrofit costs due to concurrency through the 10th low 

rate initial production contract, but at decreasing amounts. Questions 

about who will pay for additional retrofit costs under the fixed price 

contract–the contractor or the government–and how much, delayed

contract negotiations on the fifth lot. While the contract is not yet 

definitized, a December 2011 undefinitized contract action established 

that the Government and contractor would share equally in known 

concurrency costs and that any newly discovered concurrency changes 

GAO-06-356 (Washington, D.C.: Mar. 15, 2006) and GAO, Joint 

Strike Fighter: Progress Made and Challenges Remain, GAO-07-360 (Washington, D.C.: 

Apr. 2, 2007).

Testing and Production 

Overlap Increases 

Engineering Changes and 

Concurrency Costs
 

Page 27 GAO-12-437 Joint Strike Fighter

will be added to the contract and will cause a renegotiation of the target 

cost, but with no profit, according to program officials.

Defense officials have long acknowledged the substantial concurrency 

built into the JSF acquisition strategy, but until recently stated that risks 

were manageable. However, a recent high-level departmental review of 

JSF concurrency determined that the program is continuing to find 

problems at a rate more typical of early design experience on previous 

aircraft development programs, questioning the assumed design maturity 

that supported the highly concurrent acquisition strategy.18

Already, as a result of problems found in less strenuous basic 

airworthiness testing, critical design modifications are being fed back 

through the production line. For example, the program will be cutting in 

aircraft modifications to address bulkhead cracks discovered during 

airframe ground testing and STOVL auxiliary inlet door durability issues. 

More critical test discoveries are likely as the program moves into the 

more demanding phases of testing. We note also that concurrency risks 

are not just limited to incurring extra production costs, but ripple 

throughout the JSF program slowing aircraft deliveries, decreasing 

availability of aircraft, delaying pilot and maintainer training, and hindering 

the stand-up of base maintenance and supply activities, among other 

impacts.

DOD’s 

November 2011 report concluded that the “team assesses the current 

confidence in the design maturity of the F-35 to be lower than one would 

expect given the quantity of LRIP aircraft procurements planned and the 

potential cost of reworking these aircraft as new test discoveries are 

made. This lack of confidence, in conjunction with the concurrency driven 

consequences of the required fixes, supports serious reconsideration of 

procurement and production planning.” The review identified substantial 

risk of needed modifications to already produced aircraft as the flight 

testing enters into more strenuous test activities.

Producing aircraft before testing sufficiently demonstrates the design is 

mature increases the likelihood that more aircraft will be exposed to the

need for the retrofit of future design changes, which drives cost growth, 

schedule delays, and manufacturing inefficiencies. Design changes 

 

18 F-35 Joint Strike Fighter Concurrency Quick Look Review, Office of the Undersecretary 

of Defense for Acquisition, Technology and Logistics, November 29, 2011.
 

Page 28 GAO-12-437 Joint Strike Fighter

needed in one JSF variant could also impact the other two variants, 

reducing efficiencies necessary to lower production and operational costs 

with common parts and manufacturing processes for the three variants.

While the JSF program’s engineering change traffic–the monthly volume 

of changes made to engineering drawings–is declining, it is still higher 

than expected for a program entering its sixth year of production. The 

total number of engineering drawings continues to grow due to design 

changes, discoveries during ground and flight testing, and other revisions 

to drawings. Some level of design change is expected during the 

production cycle of any new and highly technical product, but excessive 

changes raise questions about the stability of the JSF’s design and its 

readiness for higher levels of production. Figure 8 tracks design changes 

over time and shows that changes are expected to persist at an elevated 

pace through 2019.

Figure 8: JSF Design Changes Over Time

A weapon system’s reliability growth rate is a good indicator of design 

maturity. Reliability is a function of specific design characteristics. A 

weapon system is considered reliable when it can perform over a 
 

Page 29 GAO-12-437 Joint Strike Fighter

specified period of time without failure, degradation, or need of repair. 

During system acquisition, reliability growth improvements should occur 

over time through a process of testing, analyzing, and fixing deficiencies 

through design changes or manufacturing process improvements. Once 

fielded, there are limited opportunities to improve a system’s reliability 

without costly redesign and retrofit. A system’s reliability rate directly 

affects its life cycle operating and support costs. We have reported in the 

past that it is important to demonstrate that the system reliability is on 

track to meet goals before production begins as changes after production 

commences can be inefficient and costly.19

According to program office data, the CTOL and STOVL variants are 

behind expected reliability growth plans at this point in the program. 

Figure 9 depicts progress of each variant in demonstrating mean flying 

hours between failures as reported by the program office in October 2011 

and compares them to 2010 rates, the expectation at this point in time, 

and the ultimate goal at maturity.

 

19 GAO, Best Practices: Capturing Design and Manufacturing Knowledge Early Improves 

Acquisition Outcomes, GAO-02-701 (Washington, D.C.: July 15, 2002).
 

Page 30 GAO-12-437 Joint Strike Fighter

Figure 9: JSF Mean Times between Failure Demonstrated to Date

As of October 2011, reliability growth plans called for the STOVL to have 

achieved at least 2.2 flying hours between failures and the CTOL at least 

3.7 hours by this point in the program. The STOVL is significantly behind 

plans, achieving about 0.5 hours between failures, or less than 25 percent 

of the plan. CTOL variant has demonstrated 2.6 hours between failures, 

about 70 percent of the rate expected at this point in time. The carrier 

variant is slightly ahead of its plan; however, it has flown many fewer 

flights and hours than the other variants.

JSF officials said that reliability rates are tracking below expectations 

primarily because identified fixes to correct deficiencies are not being 

implemented and tested in a timely manner. Officials also said the growth 

rate is difficult to track and to confidently project expected performance at 

maturity because of insufficient data from the relatively small number of 

flight hours flown. Based on the initial low reliability demonstrated thus 

far, the Director of Operational Test and Evaluation reported that the JSF 
 

Page 31 GAO-12-437 Joint Strike Fighter

has a significant challenge ahead to provide sufficient reliability growth to 

meet the operational requirement.

Restructuring actions by the Department since early 2010 have provided 

the JSF program with more achievable development and production 

goals, and has reduced, but not eliminated, risks of additional retrofit 

costs due to concurrency in current and future lots. The Department has 

progressively lowered the production ramp-up rate and cut near term 

procurement quantities; fewer aircraft procured while testing is still 

ongoing lowers the risk of having to modify already produced aircraft.

However, even with the most recent reductions in quantities, the program 

will still procure a large number of aircraft before system development is 

complete and flight testing confirms that the aircraft design and 

performance meets warfighter requirements. Table 4 shows the current 

plan that will procure 365 aircraft for $69 billion before the end of planned 

developmental flight tests.

Table 4: JSF Procurement Investments and Flight Test Progress

Source: GAO analysis of DOD budget and test plan data.

Note: Advanced procurement funding from 2006 was incorporated into fiscal year 2007 total funding, 

as 2007 was the first year of aircraft procurement. Flight testing data reflect the percentage of the 

total flight test completed at the time of the planned investment decision, which is the beginning of the 

fiscal year.

The JSF remains the critical centerpiece of DOD’s long-term tactical 

aircraft portfolio. System development of the aircraft and engine, ongoing 

for over a decade, continues to experience significant challenges. The 

program’s strategic framework – laden with concurrency – has proved to 

be problematic and, ultimately, a very costly approach. DOD has lately 

acknowledged the undue risks from concurrency and accordingly reduced 

near-term procurement and devoted more time and resources to 

Fiscal years 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

Cumulative 

procurement 

(billions of dollars) $0.8 $3.5 $7.1 $14.3 $21.3 $27.6 $33.8 $40.1 $47.9 $57.8 $69.0

Cumulative aircraft 

procured 2 14 28 58 90 121 150 179 223 289 365

Percentage of total 

planned 

development flight 

tests completed 

(est.) <1 <1 <1 1 5 17 32 52 72 91 100

Conclusions 
 

Page 32 GAO-12-437 Joint Strike Fighter

development and testing. These prudent actions have reduced, but not 

eliminated, concurrency risks of future cost growth from test discoveries 

driving changes to design and manufacturing processes. Substantial 

concurrency costs are expected to continue for several more years. 

Concurrency risks are not just limited to incurring extra modification costs, 

but ripple throughout the JSF program slowing aircraft deliveries, delaying 

release of software to testing, delaying pilot and maintainer training, and 

hindering the stand-up of base maintenance and supply activities, among 

other impacts.

Extensive restructuring actions over the last 2-plus years have placed the 

JSF program on a more achievable course, albeit a lengthier and more 

expensive one. At the same time, the near-constant churn, or change, in 

cost, schedule, and performance expectations has hampered oversight 

and insight into the program, in particular the ability to firmly assess 

progress and prospects for future success. The JSF program now needs 

to demonstrate that it can effectively perform against cost and schedule 

targets in the new baseline and deliver on its promises so that the 

warfighter can confidently establish basing plans, retire aging legacy 

aircraft, and acquire a support infrastructure. Addressing affordability risks 

will be critical in determining how many aircraft the U.S. and international 

partners can ultimately acquire and sustain over the life cycle. As 

currently structured, the program will require unprecedented levels of 

procurement funding during a period of more constrained defense budget 

expectations. Aircraft deferrals, risky funding assumptions, and future 

budget constraints make it prudent to evaluate potential impacts from 

reduced levels of funding. If funding demands cannot be fully met, it 

would be important for congressional and defense decisionmakers to 

understand the programmatic and cost impacts from lower levels of 

funding; however, DOD officials have not thoroughly analyzed JSF 

impacts should funding expectations be unmet. Going forward, it will be 

imperative to bring stability to the program and provide a firm 

understanding of near- and far-term financial requirements so that all 

parties—the Congress, Defense Department, and international partners—

can reasonably project future budgets, set priorities, and make informed 

business-based decisions amid a tough fiscal environment.

Substantial cost overruns and delivery delays on the first four low rate 

initial production contracts indicate a need to improve inefficient 

manufacturing and supply processes before ramping up production to the 

rates expected. While some manufacturing and supply performance 

indicators are showing some improvements, parts shortages, supplier 

quality and performance problems, and manufacturing workarounds still 
 

Page 33 GAO-12-437 Joint Strike Fighter

need to be addressed. DOD’s Independent Manufacturing Review Team 

identified global supply chain management as the most critical challenge 

for meeting production expectations. Effectively managing the expanding 

network of global suppliers and improving the supply chain will be key to 

improving cost and schedule outcomes, increasing manufacturing 

throughput, and enabling higher production rates.

Substantial quantities of JSF aircraft have been deferred to future years 

and funding requirements now average $12.5 billion through 2037.

Aircraft deferrals, risky funding assumptions, and future budget 

constraints make it prudent to evaluate potential impacts from reduced 

levels of funding. Therefore, we recommend that the Secretary of 

Defense direct the Director of Cost Assessment and Program Evaluation 

perform an independent analysis of the impact lower annual funding 

levels would have on the program’s cost and schedule. This sensitivity 

analysis should determine the impact of funding on aircraft deliveries, unit 

costs, and total tactical air force structure resulting from at least three

different assumed annual funding profiles, all lower than the current 

funding projection.

Finally, because of the complexity and criticality of the global supply chain 

that has already experienced some problems, we recommend the Under 

Secretary of Defense for Acquisition, Technology and Logistics direct the 

JSF program office to conduct a comprehensive assessment of the 

supply chain and transportation network to ensure it is organized, secure, 

and capable of producing and delivering parts in the quantities and times 

needed to effectively and efficiently build and sustain over 3,000 aircraft 

for the U.S. and international partners. This assessment should 

summarize opportunities as well as challenges, augmenting and building 

upon the earlier efforts of the Independent Manufacturing Review Team 

and the recent sustainment study.

DOD provided us written comments on a draft of this report, which are 

reprinted in appendix II. DOD partially concurred with our first 

recommendation and fully concurred with our second. Officials also 

provided technical comments that we incorporated in the final report as 

appropriate.

Recommendations for 

Executive Action

Agency Comments 

and our Evaluation
 

Page 34 GAO-12-437 Joint Strike Fighter

DOD partially concurred with our recommendation to perform a sensitivity 

analysis of the impact lower annual funding levels would have on JSF 

cost and schedule and the total tactical air force structure. The 

Department stated that the Director of Cost Assessment and Program 

Evaluation regularly performs this kind of analysis as part of the annual 

budget review process. However, the Department’s response 

emphasized that such analysis is pre-decisional and did not believe that 

sensitivity analyses based on notional funding levels should be published.

We agree that this budget analysis has value and that it need not be 

published publicly; however, we believe its usefulness extends beyond 

the current budget period. Increasingly tough budget decisions amid a 

likely declining top-line defense budget are in the forecast, and this kind 

of sensitivity analysis of the impact of potential lower funding levels could 

better inform defense leadership and the Congress on the longer-term 

impacts on JSF program outcomes and force structure implications.

DOD concurred with our recommendation to comprehensively assess the 

global supply chain and transportation network. The written response 

indicated that annual production readiness reviews undertaken by the 

contractor and JSF program office were sufficient and better structured to 

manage issues over several years than a one time, large scale study. We 

agree that annual targeted reviews are important and conducive to good 

near-term management, but continue to believe that these should be 

supplemented by a longer-term and more forward-looking study as we 

have recommended along the lines of the Independent Manufacturing 

Review Team.

We are sending copies of this report to the Secretary of Defense; the 

Secretaries of the Air Force, Army, and Navy; and the Director of the 

Office of Management and Budget. The report also is available at no 

charge on the GAO Web site at http://www.gao.gov. 

If you or your staff have any questions concerning this report, please 

contact me at (202) 512-4841 or sullivanm@gao.gov. Contact points for 
 

Page 35 GAO-12-437 Joint Strike Fighter

our Offices of Congressional Relations and Public Affairs may be found 

on the last page of this report. Staff members making key contributions to 

this report are listed in Appendix VI.

Michael J. Sullivan

Director

Acquisition and Sourcing Management
 

Page 36 GAO-12-437 Joint Strike Fighter

List of Committees

The Honorable Carl Levin

Chairman

The Honorable John McCain

Ranking Member

Committee on Armed Services

United States Senate

The Honorable Daniel K. Inouye

Chairman

The Honorable Thad Cochran

Ranking Member

Subcommittee on Defense

Committee on Appropriations

United States Senate

The Honorable Howard P. McKeon

Chairman

The Honorable Adam Smith

Ranking Member

Committee on Armed Services

House of Representatives

The Honorable C.W. Bill Young

Chairman

The Honorable Norman D. Dicks

Ranking Member

Subcommittee on Defense

Committee on Appropriations

House of Representatives
Appendix I: Scope and Methodology

Page 37 GAO-12-437 Joint Strike Fighter

To determine the Joint Strike Fighter (JSF) program’s progress in meeting 

cost, schedule, and performance goals, we received briefings by program 

and contractor officials and reviewed financial management reports, 

budget documents, annual Selected Acquisition Reports, monthly status 

reports, performance indicators, and other data. We identified changes in 

cost and schedule, and obtained officials’ reasons for these changes. We 

interviewed officials from the JSF program, contractors, and the 

Department of Defense (DOD) to obtain their views on progress, ongoing 

concerns and actions taken to address them, and future plans to 

complete JSF development and accelerate procurement. At the time of 

our review, the most recent Selected Acquisition Report available was 

dated December 31, 2011. Throughout most of our review, DOD was in 

the process of preparing the new acquisition program baseline, issued in 

March 2012, which reflected updated cost and schedule projections.

In assessing program cost estimates, we evaluated program cost 

estimates in the Selected Acquisition Reports since the program’s 

inception, reviewed the recent independent cost estimate completed by 

DOD’s Cost Analysis and Program Evaluation (CAPE), and analyzed 

fiscal year President’s Budget data. We interviewed JSF program office 

officials, members of CAPE, prime and engine contractors, and Defense 

Contract Management Agency officials to understand methodology, data, 

and approach in developing cost estimates and monitoring cost 

performance.

To assess plans, progress, and risks in test activities, we examined 

program documents and interviewed DOD, program office, and contractor 

officials about current test plans and progress. To assess progress 

toward test plans, we compared the number of test points accomplished 

as of December 2011 to the program’s 2011 plan for test point progress. 

We also discussed related software development, test, and integration 

with Defense Contract Management Agency (DCMA) and Director, 

Operational Test, and Evaluation (DOT&E) officials and reviewed DOT&E 

annual assessments of the JSF program, the Joint Strike Fighter 

Operational Test Team Report, and the F-35 Joint Strike Fighter 

Concurrency Quick Look Review.

To assess the program’s plans and risk in manufacturing and its capacity 

to accelerate production, we analyzed manufacturing cost and work 

performance data to assess progress against plans. We reviewed data 

and briefings provided by the program and DCMA to assess supplier 

performance and ability to support accelerated production in the near 

term. We also determined reasons for manufacturing delays, discussed 

Appendix I: Scope and Methodology
Appendix I: Scope and Methodology

Page 38 GAO-12-437 Joint Strike Fighter

program and contractor plans to improve, and projected the impact on 

development and operational tests. We interviewed contractor and DCMA 

officials to discuss the Earned Value Management System but did not 

conduct any analysis since the system has not yet been re-validated by 

DCMA.

In performing our work, we obtained information and interviewed officials 

from the JSF Joint Program Office, Arlington, Virginia; Defense Contract 

Management Agency, Fort Worth, Texas; Lockheed Martin Aeronautics, 

Fort Worth, Texas; Defense Contract Management Agency, East 

Hartford, Connecticut; and Pratt & Whitney, Middletown, Connecticut. We 

also met with and obtained data from the following offices from the 

Secretary of Defense in Washington, D.C.: Director, Operational Test and 

Evaluation; Cost Assessment and Program Evaluation; and Systems 

Engineering.

To assess the reliability of DOD and contractor data we reviewed the 

sources and uses of the data, evaluated existing information about the 

data, and interviewed agency officials knowledgeable about the data. We 

determined that the data were sufficiently reliable for the purposes of this 

report. We conducted this performance audit from June 2011 to June

2012 in accordance with generally accepted government auditing 

standards. Those standards require that we plan and perform the audit to 

obtain sufficient, appropriate evidence to provide a reasonable basis for 

our findings and conclusions based on our audit objectives. We believe 

that the evidence obtained provides a reasonable basis for our findings 

and conclusions based on our audit objectives.
Appendix II: Comments from the Department 

of Defense

Page 39 GAO-12-437 Joint Strike Fighter

Appendix II: Comments from the Department 

of Defense
Appendix II: Comments from the Department 

of Defense

Page 40 GAO-12-437 Joint Strike Fighter
Appendix II: Comments from the Department 

of Defense

Page 41 GAO-12-437 Joint Strike Fighter
Appendix III: Prior GAO Reports and DOD 

Responses

Page 42 GAO-12-437 Joint Strike Fighter

GAO report

Est. dev. costs 

dev. length 

aircraft unit cost Key program event Primary GAO message DOD response and actions

2001

GAO-02-39

$34.4 Billion

10 years

$69 Million

Start of system development 

and demonstration approved.

Critical technologies needed for 

key aircraft performance 

elements not mature. Program 

should delay start of system 

development until critical 

technologies mature to 

acceptable levels.

DOD did not delay start of 

system development and 

demonstration stating 

technologies were at acceptable 

maturity levels and will manage 

risks in development.

2005

GAO-05-271

$44.8 Billion

12 years

$82 Million

The program undergoes re-plan 

to address higher than 

expected design weight, which 

added $7 billion and 18 months 

to development schedule.

We recommended that the 

program reduce risks and 

establish executable business 

case that is knowledge-based 

with an evolutionary acquisition 

strategy.

DOD partially concurred but did 

not adjust strategy, believing 

that its approach is balanced 

between cost, schedule and 

technical risk.

2006

GAO-06-356

$45.7 Billion

12 years

$86 Million

Program sets in motion plan to 

enter production in 2007 shortly 

after first flight of the nonproduction representative 

aircraft. 

The program plans to enter 

production with less than 1 

percent of testing complete. We 

recommended program delay 

investing in production until 

flight testing shows that JSF 

performs as expected.

DOD partially concurred but did 

not delay start of production 

because it believed the risk 

level was appropriate.

2007

GAO-07-360

$44.5 Billion

12 years

$104 Million

Congress reduced funding for 

first two low-rate production 

buys thereby slowing the ramp 

up of production.

Progress was being made but 

concerns remained about 

undue overlap in testing and 

production. We recommended 

limits to annual production 

quantities to 24 a year until 

flying quantities are 

demonstrated.

DOD non-concurred and felt 

that the program had an 

acceptable level of concurrency 

and an appropriate acquisition 

strategy.

2008

GAO-08-388

$44.2 Billion

12 years

$104 Million

DOD implemented a MidCourse Risk Reduction Plan to 

replenish management 

reserves from about $400 

million to about $1 billion by 

reducing test resources.

We believed new plan actually 

increased risks and 

recommended that DOD revise 

the plan to address concerns 

about testing, use of 

management reserves, and 

manufacturing. We determined 

that the cost estimate was not 

reliable and that a new cost 

estimate and schedule risk 

assessment is needed.

DOD did not revise risk plan or 

restore testing resources, 

stating that it will monitor the 

new plan and adjust it if 

necessary. Consistent with a 

report recommendation, a new 

cost estimate was eventually 

prepared, but DOD refused to 

do a risk and uncertainty 

analysis that we felt was 

important to provide a range 

estimate of potential outcomes. 

Appendix III: Prior GAO Reports and DOD 

Responses 
Appendix III: Prior GAO Reports and DOD 

Responses

Page 43 GAO-12-437 Joint Strike Fighter

GAO report

Est. dev. costs 

dev. length 

aircraft unit cost Key program event Primary GAO message DOD response and actions

2009

GAO-09-303

$44.4 Billion

13 years

$104 Million

The program increased the cost 

estimate and adds a year to 

development but accelerated 

the production ramp up. 

Independent DOD cost 

estimate (JET I) projects even 

higher costs and further delays.

Because of development 

problems, we stated that 

moving forward with an 

accelerated procurement plan 

and use of cost reimbursement 

contracts is very risky. We 

recommended the program 

report on the risks and 

mitigation strategy for this 

approach.

DOD agreed to report its 

contracting strategy and plans 

to Congress. In response to our 

report recommendation, DOD 

subsequently agreed to do a 

schedule risk analysis. The 

program reported completing 

the first schedule risk 

assessment in summer 2011 

with plans to update about 

every 6 months. In February 

2010, the Department 

announced a major 

restructuring of the JSF 

program, including reduced 

procurement and a planned 

move to fixed-price contracts.

2010

GAO-10-382

$49.3 Billion

15 years

$112 Million

The program was restructured 

to reflect findings of recent 

independent cost team (JET II) 

and independent manufacturing 

review team. As a result, 

development funds increased, 

test aircraft were added, the 

schedule was extended, and 

the early production rate 

decreased.

Because of additional costs and 

schedule delays, the program’s 

ability to meet warfighter 

requirements on time is at risk. 

We recommend the program

complete a full comprehensive 

cost estimate and assess 

warfighter and IOC 

requirements. We suggest that 

Congress require DOD to 

prepare a “system maturity 

matrix”–a tool for tying annual 

procurement requests to 

demonstrated progress.

DOD continued restructuring 

actions and announced plans to 

increase test resources and 

lower the production rate. 

Independent review teams 

evaluated aircraft and engine 

manufacturing processes. As 

we projected in this report, cost 

increases later resulted in a 

Nunn-McCurdy breach. Military 

services are currently reviewing 

capability requirements as we 

recommended.

2011

GAO-11-325

$51.8 Billion

16 years

$133 Million

Restructuring continued 

following the Nunn-McCurdy 

certification with additional 

development cost increases; 

schedule growth; further 

reduction in near-term 

procurement quantities; and 

decreased the rate of increase 

for future production. The 

Secretary of Defense placed 

the STOVL variant on a 2 year 

probation; decoupled STOVL 

from the other variants in the 

testing program because of 

lingering technical issues; and 

reduced STOVL production 

plans for fiscal years 2011 to 

2013.

The restructuring actions are 

positive and if implemented 

properly, should lead to more 

achievable and predictable 

outcomes. Concurrency of 

development, test, and 

production is substantial and 

provides risk to the program. 

We recommended the program 

maintain funding levels as 

budgeted in the FY 2012-2016 

future years’ defense plan; 

establish criteria for STOVL 

probation; and conduct an 

independent review of software 

development, integration, and 

test processes.

DOD concurred with all three of 

the recommendations. In 

January 2012, the Secretary of 

Defense lifted STOVL 

probation, citing improved 

performance. Subsequently, the 

Secretary further reduced 

procurement quantities, 

decreasing funding 

requirements through 2016. The 

initial independent software 

assessment began in 

September 2011, and ongoing 

reviews are planned through 

2012.

Source: DOD data and GAO analysis in prior reports cited above.
Appendix IV: Budgeted Funding and 

Procurement Quantities, FY 2011-2017

Page 44 GAO-12-437 Joint Strike Fighter

(Dollars in millions)

Development funding 2011 2012 2013 2014 2015 2016 2017 Total

Air Force (CTOL) $932 $1,398 $1,218 $1,069 $741 $520 $386 $6,263

Navy (CV) 654 659 744 702 584 458 350 4,151

Marine Corps (STOVL) 602 652 737 693 575 448 340 4,048

U.S. total $2,188 $2,708 $2,699 $2,465 $1,900 $1,427 $1,075 $14,462

Procurement funding 2011 2012 2013 2014 2015 2016 2017 Total

Air Force (CTOL) $4,302 $3,519 $3,566 $3,515 $4,793 $6,250 $6,202 $32,146

Navy (CV) 1,853 1,557 1,073 1,274 1,432 1,724 2,430 11,343

Marine Corps (STOVL) 838 1,259 1,511 1,521 1,562 1,953 2,577 11,221

U.S. total $6,993 $6,335 $6,149 $6,311 $7,787 $9,927 $11,208 $54,710

Quantity 2011 2012 2013 2014 2015 2016 2017 Total

Air Force (CTOL) 22 18 19 19 32 48 48 206

Navy (CV) 7 7 4 4 6 9 14 51

Marine Corps (STOVL) 3 6 6 6 6 9 14 50

U.S. total 32 31 29 29 44 66 76 307

Source: GAO analysis of Fiscal Year 2013 President’s Budget materials and JSF program office data.

Note: Numbers may not add due to rounding.

Appendix IV: Budgeted Funding and 

Procurement Quantities, FY 2011-2017
Appendix V: Short Takeoff and Vertical 

Landing Aircraft Probation Period and 

Progress

Page 45 GAO-12-437 Joint Strike Fighter

In January 2011, the Secretary of Defense placed the short takeoff and 

vertical landing (STOVL) aircraft on “probation” for 2 years, citing 

technical issues unique to the variant that would add to the aircraft’s cost 

and weight. The probation limited the U.S. STOVL procurement to three 

aircraft in fiscal year 2011 and six aircraft in fiscal year 2012 and 

decoupled STOVL testing from CV and CTOL testing so as not to delay 

those variants. The 2 year probation was expected to provide enough 

time to address STOVL-specific technical issues, engineer solutions, and 

assess their impact. It was presumed that at the end of probation, an 

informed decision could be made about whether and how to proceed with 

STOVL, but no specific exit criteria were established. In our 2011 report1

In January 2012, the new Secretary of Defense lifted the STOVL 

probation after 1 year, citing improved performance and completion of the 

initial sea trials aboard the U.S.S. Wasp as a basis for the decision. In its 

report to Congress

, 

we recommended that the program establish criteria for the STOVL 

probation period and take additional steps to sustain individual attention 

on STOVL-specific issues to ensure cost and schedule milestones were 

achieved in order to deliver required warfighter capabilities.

2

 

1

, the Department explained that STOVL progress was 

continually monitored throughout the probation period with a holistic view 

of the weapon system, and reiterated that the STOVL was not placed on 

probation with specific exit criteria. The report stated that the 

Commandant of the Marine Corps completed monthly reviews of STOVL 

progress in addition to the monthly Service Acquisition Executive reviews 

of the JSF program, and that this provided the individual focus required to 

balance cost, schedule, and development progress against warfighter 

utility. These reviews assessed categories of STOVL weight and vertical 

lift propulsion performance, availability, and ship suitability in fleet 

operation, as well as the costs to modify, operate and procure the aircraft.

Throughout 2011, the STOVL variant increased test flight rates and 

STOVL-specific mode testing, surpassing planned test point progress for 

the year. In ending probation, the Department concluded that sufficient 

progress in STOVL development, test, and production had been made 

such that no uniquely distinguishing issues required that it receive more 

GAO-11-325. 

2 Under Secretary of Defense Acquisition, Technology and Logistics Report to Congress 

on Probationary Period in Development of Short Take-off, Vertical Landing Variant of the 

Joint Strike Fighter: National Defense Authorization Act for Fiscal Year 2012, section 148.

Appendix V: Short Takeoff and Vertical 

Landing Aircraft Probation Period and 

Progress
Appendix V: Short Takeoff and Vertical 

Landing Aircraft Probation Period and 

Progress

Page 46 GAO-12-437 Joint Strike Fighter

scrutiny than the other two variants. According to the department, interim 

solutions are in place to mitigate the lingering technical issues with the 

STOVL and permanent solutions are in varying stages of development or 

implementation.

While the probation period did not include specific criteria, the reasons 

given for probation were to address technical issues, engineer solutions, 

and assess impact, and it was expected to take 2 years to do so.

Although we note that several technical issues have been addressed and 

some potential solutions engineered, assessing whether the deficiencies 

are resolved is ongoing and, in some cases, will not be known for years.

Table 5 provides details on the STOVL technical problems identified at 

the onset of probation, the efforts to resolve the problems, and 

timeframes for implementing fixes. According to the program, of the five 

specific problems cited, two are considered to be fixed (bulkhead cracks 

and air inlet door loads) while the other three have temporary fixes in 

place. The Director, Operational Test and Evaluation (DOT&E) officials 

reported that significant work remains to verify and incorporate 

modifications to correct known STOVL deficiencies and prepare the 

system for operational use. Until the proposed technical solutions have 

been fully tested and demonstrated, it cannot be determined if the 

technical problems have been resolved.
Appendix V: Short Takeoff and Vertical 

Landing Aircraft Probation Period and 

Progress

Page 47 GAO-12-437 Joint Strike Fighter

Table 5: STOVL Technical Problems Identified for Probation Period 

Technical Problem Design Fix Reported Status

Production

Cut-in

Bulkhead cracks developed before 2,000 

hours of fatigue/durability testing. 

Requirement is 8,000 hours.

Bulkhead redesign for production, 

with fixes identified for retrofit as 

needed.

Redesign has been completed and 

fatigue/durability test resumed in 

January 2012.

 - 

Excessive loads on the auxiliary air inlet 

doors, causing higher than expected 

wear and fatigue.

Door redesign. Flight testing began in December 

2011 on redesigned door installed on 

BF-1. According to the program 

office, analyses of the results from 

early test flights are promising.

BF-38

LRIP 6

Higher-than-expected heating of the lift 

fan clutch during conventional flight.

An interim solution is a 

temperature sensor that alerts the 

pilot to take corrective action if the 

clutch exceeds acceptable 

temperatures. A final solution for 

the heat problem has yet to be 

determined.

The temperature sensor has been 

added to aircraft as the interim 

measure. A detailed root cause 

investigation for a permanent fix to 

eliminate lift fan clutch heating is 

underway.

BF-44

LRIP 7

Thermal growth of the airframe and 

engine exceed the current lift fan drive 

shaft stretch/compression capability.

Interim solution is to add spacers 

to the lift fan driveshaft to 

accommodate unanticipated 

thermal expansion and contraction. 

This eliminates airworthiness 

concerns. Final solution is to 

redesign the driveshaft. 

Spacers have been added to ensure 

airworthiness for the interim solution. 

A new driveshaft that can meet actual 

aircraft environmental requirements is 

in the early phases of the design 

process.

BF-44

LRIP 7 

Roll post nozzle bay temperatures 

exceed current actuator capability.

Interim solution is to insulate the 

actuator with a thermal blanket. 

Final fix expected to be a 

redesigned actuator.

Airworthiness risk mitigated by 

thermal blanket. The critical design 

review for a new actuator design that 

will eliminate the need for a thermal 

blanket was conducted January 2012.

TBD

Source: GAO analysis of DOD data.
Appendix VI: GAO Contact and Staff 

Acknowledgments

Page 48 GAO-12-437 Joint Strike Fighter

Michael Sullivan (202) 512-4841 or sullivanm@gao.gov

In addition to the contact name above, the following staff members made 

key contributions to this report: Bruce Fairbairn, Assistant Director; 

Charlie Shivers; Sean Merrill; LeAnna Parkey; Dr. W. Kendal Roberts; 

Laura Greifner; and Matt Lea.

Appendix VI: GAO Contact and Staff 

Acknowledgments 

GAO Contact 

Acknowledgments 
Related GAO Products

Page 49 GAO-12-437 Joint Strike Fighter

Defense Acquisitions: Assessments of Selected Weapon Programs. 

GAO-12-400SP. Washington, D.C.: March 29, 2012.

Joint Strike Fighter: Restructuring Added Resources and Reduced Risk, 

but Concurrency Is Still a Major Concern. GAO-12-525T. Washington, 

D.C.: March 20, 2012.

Joint Strike Fighter: Implications of Program Restructuring and Other 

Recent Developments on Key Aspects of DOD’s Prior Alternate Engine 

Analyses. GAO-11-903R. Washington, D.C.: September 14, 2011.

Joint Strike Fighter: Restructuring Places Program on Firmer Footing, but 

Progress Is Still Lagging. GAO-11-677T. Washington, D.C.: May 19, 

2011.

Joint Strike Fighter: Restructuring Places Program on Firmer Footing, but 

Progress Still Lags. GAO-11-325. Washington, D.C.: April 7, 2011.

Joint Strike Fighter: Restructuring Should Improve Outcomes, but 

Progress Is Still Lagging Overall. GAO-11-450T. Washington, D.C.: 

March 15, 2011.

Tactical Aircraft: Air Force Fighter Force Structure Reports Generally 

Addressed Congressional Mandates, but Reflected Dated Plans and 

Guidance, and Limited Analyses. GAO-11-323R. Washington, D.C.: 

February 24, 2011.

Defense Management: DOD Needs to Monitor and Assess Corrective 

Actions Resulting from Its Corrosion Study of the F-35 Joint Strike 

Fighter. GAO-11-171R. Washington D.C.: December 16, 2010.

Joint Strike Fighter: Assessment of DOD’s Funding Projection for the 

F136 Alternate Engine. GAO-10-1020R. Washington, D.C.: September 

15, 2010.

Tactical Aircraft: DOD’s Ability to Meet Future Requirements is Uncertain, 

with Key Analyses Needed to Inform Upcoming Investment Decisions. 

GAO-10-789. Washington, D.C.: July 29, 2010.

Defense Acquisitions: Assessments of Selected Weapon Programs. 

GAO-10-388SP. Washington, D.C.: March 30, 2010.

Related GAO Products
Related GAO Products

Page 50 GAO-12-437 Joint Strike Fighter

Joint Strike Fighter: Significant Challenges and Decisions Ahead. 

GAO-10-478T. Washington, D.C.: March 24, 2010.

Joint Strike Fighter: Additional Costs and Delays Risk Not Meeting 

Warfighter Requirements on Time. GAO-10-382. Washington, D.C.: 

March 19, 2010.

Joint Strike Fighter: Significant Challenges Remain as DOD Restructures 

Program. GAO-10-520T. Washington, D.C.: March 11, 2010.

Joint Strike Fighter: Strong Risk Management Essential as Program 

Enters Most Challenging Phase. GAO-09-711T. Washington, D.C.: May 

20, 2009. 

Defense Acquisitions: Assessments of Selected Weapon Programs. 

GAO-09-326SP. Washington, D.C.: March 30, 2009.

Joint Strike Fighter: Accelerating Procurement before Completing 

Development Increases the Government’s Financial Risk. GAO-09-303. 

Washington D.C.: March 12, 2009.

Defense Acquisitions: Better Weapon Program Outcomes Require 

Discipline, Accountability, and Fundamental Changes in the Acquisition 

Environment. GAO-08-782T. Washington, D.C.: June 3, 2008.

Defense Acquisitions: Assessments of Selected Weapon Programs. 

GAO-08-467SP. Washington, D.C.: March 31, 2008.

Joint Strike Fighter: Impact of Recent Decisions on Program Risks. 

GAO-08-569T. Washington, D.C.: March 11, 2008.

Joint Strike Fighter: Recent Decisions by DOD Add to Program Risks. 

GAO-08-388. Washington, D.C.: March 11, 2008.

Tactical Aircraft: DOD Needs a Joint and Integrated Investment Strategy. 

GAO-07-415. Washington, D.C.: April 2, 2007.

Defense Acquisitions: Analysis of Costs for the Joint Strike Fighter Engine 

Program. GAO-07-656T. Washington, D.C.: March 22, 2007.

Joint Strike Fighter: Progress Made and Challenges Remain. 

GAO-07-360. Washington, D.C.: March 15, 2007.
Related GAO Products

Page 51 GAO-12-437 Joint Strike Fighter

Tactical Aircraft: DOD’s Cancellation of the Joint Strike Fighter Alternate 

Engine Program Was Not Based on a Comprehensive Analysis. 

GAO-06-717R. Washington, D.C.: May 22, 2006.

Defense Acquisitions: Major Weapon Systems Continue to Experience 

Cost and Schedule Problems under DOD’s Revised Policy. GAO-06-368. 

Washington, D.C.: April 13, 2006.

Defense Acquisitions: Actions Needed to Get Better Results on Weapons 

Systems Investments. GAO-06-585T. Washington, D.C.: April 5, 2006.

Tactical Aircraft: Recapitalization Goals Are Not Supported by 

Knowledge-Based F-22A and JSF Business Cases. GAO-06-487T. 

Washington, D.C.: March 16, 2006.

Joint Strike Fighter: DOD Plans to Enter Production before Testing 

Demonstrates Acceptable Performance. GAO-06-356. Washington, D.C.: 

March 15, 2006.

Joint Strike Fighter: Management of the Technology Transfer Process. 

GAO-06-364. Washington, D.C.: March 14, 2006.

Tactical Aircraft: F/A-22 and JSF Acquisition Plans and Implications for 

Tactical Aircraft Modernization. GAO-05-519T. Washington, D.C: April 6, 

2005.

Tactical Aircraft: Opportunity to Reduce Risks in the Joint Strike Fighter 

Program with Different Acquisition Strategy. GAO-05-271. Washington, 

D.C.: March 15, 2005.

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