F-35 Joint Strike Fighter: Continued Oversight Needed as Program Plans to Begin Development of New Capabilities
Published: 2016-04-14T00:00:00

Fast Facts:

Highlights:
section_title: Why GAO Did This Study
paragraphs: With estimated acquisition costs of nearly $400 billion, the F-35 Joint Strike Fighter—also known as the Lightning II —aircraft is DOD's most costly and ambitious acquisition program. Since 2001, GAO has reported extensively on the F-35 program's cost, schedule, and performance problems. The program plans to begin increasing production rates over the next few years.
The National Defense Authorization Act for Fiscal Year 2015 contains a provision for GAO to review the F-35 acquisition program. This report assesses program (1) affordability, remaining development, and ongoing manufacturing, and (2) future modernization and procurement plans.
GAO analyzed total program funding requirements. GAO analyzed program documentation including management reports, test data and results, and internal DOD program analyses. GAO also collected and analyzed production and supply chain performance data, and interviewed DOD, program, and contractor officials.
section_title: What GAO Found
paragraphs: Although the estimated F-35 Joint Strike Fighter (F-35) program acquisition costs have decreased since 2014, the program continues to face significant affordability challenges. The Department of Defense (DOD) plans to begin increasing production and expects to spend more than $14 billion annually for nearly a decade on procurement of F-35 aircraft. Currently, the program has around 20 percent of development testing remaining, including complex mission systems software testing, which will be challenging. At the same time, the contractors that build the F-35 airframes and engines continue to report improved manufacturing efficiency and supply chain performance.
DOD plans to manage F-35 modernization as part of the existing program baseline and is exploring the use of a single contract to procure multiple lots of future aircraft. Both courses of action have oversight implications. DOD has begun planning and funding significant new development work to add to the F-35's capabilities. Known as Block 4, the funding needed for this effort is projected to be nearly $3 billion over the next 6 years (see figure below), which would qualify it as a major defense acquisition program in its own right.
DOD does not currently plan to manage Block 4 as a separate program with its own acquisition program baseline but rather as part of the existing baseline. As a result, Block 4 will not be subject to key statutory and regulatory oversight requirements, such as providing Congress with regular, formal reports on program cost and schedule performance. A similar approach was initially followed on the F-22 Raptor modernization program, making it difficult to separate the performance and cost of the modernization from the baseline program. Best practices recommend an incremental approach in which new development efforts are structured and managed as separate acquisition programs with their own requirements and acquisition program baselines. The F-22 eventually adopted this approach. If the Block 4 effort is not established as a separate acquisition program, transparency will be limited. Therefore, it will be difficult for Congress to hold it accountable for achieving its cost, schedule, and performance requirements.
section_title: What GAO Recommends
paragraphs: Congress should consider directing DOD to manage F-35 follow-on modernization, Block 4, as a separate and distinct acquisition program with its own baseline and regular cost, schedule and performance reporting. GAO included this matter for consideration because DOD did not concur with GAO's recommendation to manage Block 4 as a separate acquisition program. GAO continues to believe this recommendation is valid as discussed in this report.

section_title: Letter
paragraphs: With estimated acquisition costs of nearly $400 billion, the F-35 Joint  Strike Fighter (F-35)—also known as the Lightning II—is the Department  of Defense’s (DOD) most costly and ambitious acquisition program.  Through this program, DOD is developing and fielding a family of next  generation strike fighter aircraft, integrating low observable (stealth)  technologies with advanced sensors and computer networking  capabilities for the United States Air Force, Marine Corps, and Navy as  well as eight international partners. The F-35 family is comprised of the  F-35A conventional takeoff and landing variant, the F-35B short takeoff  and vertical landing variant, and the F-35C carrier-suitable variant. The  program is approaching the end of development and will begin increasing  production rates significantly over the next few years. According to  current projections, the U.S. portion of the program will require acquisition  funding of $54 billion over the next five years as it approaches full rate  production and is expected to require about $12 billion a year, on  average, through 2038 to complete development and procure a total of  2,457 aircraft. In addition, DOD and program office estimates indicate that  the F-35 fleet could cost over $1 trillion to operate and support over its  lifetime, which will pose significant affordability challenges.
We have reported on F-35 issues for many years. For example, the  National Defense Authorization Act for Fiscal Year 2010 included a  provision for GAO to review the F-35 acquisition program annually for 6  years. The last report under that provision was issued in April 2015.  Similarly, over time, we have reported significant cost, schedule, and  performance problems and have made numerous recommendations for  improvement. DOD has taken action to address many of our  recommendations to varying degrees. See appendix I for a matrix of prior  recommendations and related DOD actions. In addition, a list of related  GAO reports is included at the end of the report.
The National Defense Authorization Act for Fiscal Year 2015 included a  provision for GAO to continue reviewing the F-35 acquisition program  annually until the program reaches full-rate production. This is the first  report under that provision, and in this report we assess (1) program cost  and affordability; (2) remaining development and testing; (3) ongoing  manufacturing including supply chain performance; and (4) future  modernization and procurement plans.
To assess program cost and affordability, we reviewed and analyzed total  program funding requirements to project annual funding requirements  through 2038. To assess the program’s remaining development and  testing, we reviewed and analyzed program briefings, test data and  results, and internal DOD program analyses. We collected data on and  discussed key aspects of F-35 development and test progress with  program management and contractor officials as well as DOD test  officials and program test pilots. To assess ongoing manufacturing and  supply chain performance, we collected and analyzed manufacturing and  supply chain performance data from DOD, Lockheed Martin, and Pratt &  Whitney. To assess future modernization and procurement plans, we  reviewed budget documents to identify costs associated with the  modernization effort and collected and analyzed information regarding  capability and oversight plans. We also reviewed and analyzed best  practices identified by GAO and reviewed relevant DOD policies and  statutes. We also discussed cost and manufacturing efficiency initiatives,  such as the block buy approach, with contractor and program office  officials to understand potential cost savings and plans. We discussed the  program’s plans with program office officials. We assessed the reliability  of the cost, schedule, and performance data by reviewing supporting  documentation and interviewing knowledgeable officials. Based on these  steps, we determined that all of the data we used were sufficiently reliable  for the purposes of this report. Appendix Il contains a more detailed  description of our scope and methodology.
We conducted this performance audit from June 2015 to April 2016 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.
subsections: section_title: Background
paragraphs: As we have previously reported, DOD began the F-35 acquisition  program in October 2001 without adequate knowledge about the aircraft’s  critical technologies or design. In addition, DOD’s acquisition strategy  called for high levels of concurrency between development, testing, and  production. In our prior work, we identified the lack of knowledge and  high levels of concurrency as major drivers in the significant cost and  schedule growth as well as performance shortfalls that the program has  experienced since 2001. The program has been restructured three times  since it began: first in December 2003, again in March 2007, and most  recently in March 2012. The most recent restructuring was initiated in  early 2010 when the program’s unit cost estimates exceeded critical  thresholds established by statute—a condition known as a Nunn- McCurdy breach. DOD subsequently certified to Congress in June 2010  that the program was essential to national security and needed to  continue. DOD then began restructuring the program. The restructuring  continued through 2011 and into 2012, during which time the department  established a new acquisition program baseline reflecting increased  program cost estimates, extended test and delivery schedules, and  reduced near-term aircraft procurement quantities—total procurement  quantities did not change. Figure 1 shows how planned aircraft  procurement quantities in the near-term have declined over time.
While F-35 program cost, quantity, and schedule estimates increased  significantly between the initial program baseline in 2001 and latest  baseline in 2012, they have remained relatively stable over the past 3  years. Table 1 shows the cost, quantity, and schedule changes from the  initial program baseline and the relative stability since the new baseline  was established.
In March 2012, when the new acquisition program baseline was finalized,  DOD had not yet identified new initial operating capability dates for the  military services. The following year, DOD issued a memorandum stating  that the Marine Corps and Air Force were planning to field initial operating  capabilities in 2015 and 2016 respectively, and that the Navy planned to  field its initial operating capability in 2018. These new dates represented  a delay of 5 to 6 years from the program’s initial baseline dates. The  Marine Corps declared initial operational capability in July 2015.
section_title: Program Continues to Face Affordability Challenges
paragraphs: The F-35 program continues to face affordability challenges. The F-35 is  still DOD’s most costly acquisition program. As of December 2015, the  estimated total acquisition cost for the F-35 program is $379 billion, or  $12.1 billion less than DOD reported in 2014. The program will require an  average of $12 billion per year to complete the procurement of aircraft  through 2038. The program expects to reach peak production rates for  U.S. aircraft in 2022, at which point DOD expects to spend more than $14  billion a year on average for a decade (see figure 2). These affordability  challenges will compound as the program competes with other large  acquisition programs including the long range strike bomber and KC-46A  Tanker. At the same time, the number of operational F-35 aircraft that  DOD will have to support will be increasing. The total cost to operate and  support the F-35 fleet is still estimated to be more than $1 trillion. In  recent years, affordability challenges, in part, have forced the Air Force to  defer F-35 aircraft procurements to later years. Since 2014, the Air Force  deferred 45 aircraft between 2017 and 2021 to later years. This will likely  require the military service to make unplanned investments in extending  the service life of their current fighter aircraft. The cost of extending the  lives of current fighter aircraft and acquiring other major weapon systems,  while continuing to produce and field new F-35 aircraft, poses significant  affordability risks in a period of austere defense budgets.
section_title: Initial Development is Nearing Completion and F-35 Program is Addressing Technical Risks
paragraphs: The F-35 program is nearing the completion of the developmental test  program with about 20 percent of its flight sciences and mission systems  testing remaining; however the remaining testing is likely to be  challenging as it will require complex missions and stressing  environments. Developmental flight testing is separated into two key  areas referred to as flight sciences and mission systems. Developmental  flight science testing is done to verify the aircraft’s basic flying  capabilities, while mission systems testing is done to verify that the  software and systems that provide warfighting capabilities function  properly and meet requirements. The remaining mission systems testing  will consist of a large number of weapons accuracy events which have  proven to be difficult in the past. Any delay could pose risk to the timely  start of initial operational test and evaluation and could also increase  concurrency costs. As developmental testing progresses, program  officials continue to address and identify technical risks.
subsections: section_title: Developmental Flight Testing Is Nearing Completion with Challenging Mission Systems Software Testing Remaining
paragraphs: The F-35 program is nearing the completion of developmental flight  testing with only 20 percent of its total planned test points remaining. As  of December 2015, the program completed 6,201 of the 6,264 planned  flight science test points for the year and overall flight science testing was  80 percent complete. Before completing the remaining high speed and  high altitude flight science testing, Lockheed Martin officials noted that  they will incorporate a pressure relief valve into the aircraft’s fuel system  to allow the aircraft to fly at altitudes and speeds that are currently  restricted due to fuel pressure concerns. Lockheed Martin plans to  implement this change by mid-2016. Figure 3 below shows the program’s  progress toward completing flight science testing.
DOD is developing, testing, and fielding mission systems capabilities in  software blocks. Figure 4 illustrates the mission systems software blocks  being developed for the program, the percent of test points completed by  block, and the build-up to full warfighting capability with Block 3F the final  software block in the current development program.
While the program completed all of the mission systems software testing  planned in 2015, much of its Block 3F testing remains and it could be  challenging given the complexity of the missions and the stressing  environments that are required. The program completed 3,381 mission  systems test points, 218 more than the 3,163 test points planned in 2015.  As of December 2015, the program had about 20 percent of mission  systems testing remaining. Block 3F flight testing started later than  planned and program officials believe that the completion of 3F  developmental testing could be delayed by about 2 to 3 months. As of  December 2015, our analysis of program data indicated that Block 3F  testing could be delayed by as much as 6 months if the program performs  at the same rate it has in the past and is executed according to the  current plan with no additional test point growth. A recent report by the  Director of Operational Test and Evaluation Office noted completion of  mission systems testing would likely be delayed until January 2018, or 8  months later than planned.
Although early software blocks (Blocks 1 through 3i) have completed  testing, the program continues to experience problems with some mission  system software functions shutting down and restarting during flight  testing. Officials believed they had identified a fix at the end of 2015, but  recent tests indicate problems still exist. Program officials plan to continue  addressing the issue during 2016 in order to meet the Air Force initial  operational capability in August 2016. Program officials are also  concerned about the tight timeframes to conduct the 55 weapons  accuracy events that remain—30 of which are related to a gun. As of  December 2015, the program had completed 17 weapons events many of  which were delayed by months due to software deficiencies and fleet  groundings. Program officials are analyzing the remaining test schedule  to identify potential efficiencies in their weapons test plan. Any delays in  developmental testing could pose risk to the timely start of initial  operational test and evaluation, currently planned for December 2017.
Delays in mission systems software testing could also increase costs. As  the program conducts developmental testing it also continues to procure  more and more aircraft per year, increasing program concurrency and  cost risk. Through 2016 the program will have spent $56.1 billion to  procure 285 aircraft. Fixes to problems identified during testing have  required retrofits and rework to aircraft that had already been delivered.  To date, program officials have identified a total of $1.4 billion to fix  known issues and have forecasted an additional $369 million for retrofits  and rework related to issues that have yet to be discovered in testing  through 2016. Beyond 2016, the program will no longer track concurrency  costs in the same way because developmental testing is expected to be  complete and the program does not believe that much, if any,  concurrency risk will remain. However, developmental and initial  operational testing will continue beyond this period. By the time initial  operational testing is complete, currently planned for 2019, the program  will have procured 498 aircraft at a cost of $85.7 billion. DOD has taken  steps over the past few years to decrease the costs of concurrency. For  example, officials have tried to incorporate fixes into production earlier in  order to limit the number of fielded aircraft that require retrofits. However,  any delays in testing will likely result in delays in the incorporation of  known fixes, which would increase the number of aircraft that will require  retrofits and rework and increase concurrency costs.
section_title: Program Identifying and Addressing Technical Risks
paragraphs: As developmental testing nears completion, the F-35 program continues  to address technical risks. The program has incorporated design changes  that appear to have mitigated several of the technical risks that we have  highlighted in prior reports, including problems with the arresting hook  system and bulkhead cracks on the F-35B. However, over the past year,  the program continued to address risks with the Helmet Mounted Display,  Autonomic Logistics Information System (ALIS), and engine seal that we  have identified in the past. The program also identified new risks with the  ejection seat and cracking in the F-35C wing structure. The status of  DOD’s effort to address these issues as of December 2015 is as follows:
Helmet Mounted Display—A new helmet intended to address  shortfalls in night vision capability, among other things, was  developed and delivered to the program in 2015. Developmental  testing of the new helmet is mostly complete, with final verification  testing planned in 2016.
ALIS—ALIS continues to face risks. For example, the system may not  be deployable and does not have a back-up, should the hardware  system fail. These and other ALIS risks, identified in a report issued in  April 2016 may result in further schedule delays and cost increases.  In addition, ALIS continues to lack required capabilities; for instance,  equipment management data is inaccurate or incomplete, and engine  health information is not included in the current version of ALIS. The  program office is taking steps to address these issues including  procuring alternate hardware in case of a failure and working with the  contractor to improve data quality processes.
Engine Seal— Program officials have identified a design change to  address the technical problem that resulted in an engine fire in June  2014. This design change has been validated and incorporated into  production. Program and engine contractor officials have identified  180 total engines that will need to be retrofitted, and as of September  2015, 69 of those retrofits had been completed, including all of the  test aircraft. The engine contractor, Pratt & Whitney, is paying for the  retrofits.
Ejection Seat—In 2015, program officials discovered that pilots under  136 pounds could possibly suffer neck injuries during ejection.  Officials stated the risk of injury is due to the rotation of the ejection  seat in combination with the thrust from the parachute deployment  during ejection. Officials noted that although the problem was  discovered during testing of the new helmet mounted display, the  helmet’s weight was not the root cause. The program is exploring a  number of solutions to ensure pilot safety including installing a switch  for pilots that would slow the release of the parachute, installing a  head rest that would reduce head movement, and reduce the weight  of the helmet. The cost of these changes has not yet been  determined.
Wing Structure Cracks—In 2015, at around 13,700 hours of durability  testing—about 85 percent of the total hours required—program  officials recognized cracking in the wing structure of the F-35C  structural test aircraft. Testing was halted for about 3 months while the  test aircraft was repaired with internal and external straps to  strengthen the structure. Lockheed Martin officials we spoke with  stated that a long-term fix had not been identified. However, the  impact on current fielded aircraft will likely be minimal because few F- 35C aircraft have been delivered and the discovery occurred beyond  the aircraft’s expected lifecycle.
section_title: Manufacturing and Reliability Progress Continue
paragraphs: The F-35 airframe and engine contractors continue to report improved  efficiency and supply chain performance, and program data indicates that  reliability and maintainability are also improving. The number of U.S.  aircraft produced and delivered by the F-35 prime contractor, Lockheed  Martin has remained relatively stable in each of the last four years. As  more aircraft are produced, Lockheed Martin’s manufacturing efficiency  and quality metrics have also improved. In contrast, manufacturing  efficiency and quality metrics have remained relatively stable for Pratt &  Whitney, the engine contractor. At the same time, aircraft reliability and  maintainability have continued to improve, although at slower rates than  program officials expected.
subsections: section_title: Airframe Manufacturing Efficiency and Quality Continue to Improve
paragraphs: Over the last four years, the number of U.S. aircraft produced and  delivered by the F-35 prime contractor, Lockheed Martin, has remained  relatively stable. Since 2011, a total of 154 aircraft have been delivered to  DOD and international partners, 45 of which were delivered in 2015.  Figure 5 shows the number of U.S. and international partner aircraft  delivered, as well as the number of F-35 aircraft in production at  Lockheed Martin and its suppliers as of December 2015.
Although prior to 2015 Lockheed Martin had only delivered one aircraft on  or ahead of their contracted delivery date, the contractor has been  making progress, and in 2015, was able to deliver 15 of the 45 aircraft on  time or early. As Lockheed Martin delivers more aircraft, the number of  average labor hours needed to manufacture each aircraft continues to  decline. Since 2011 average labor hours per aircraft have declined 60  percent on average since the first F-35 aircraft was delivered. Lockheed  Martin officials stated that their goal is to reduce the average labor hours  to around 30,000 hours by 2019. Based on the labor hour trends depicted  in figure 6, Lockheed Martin appears to be on track to achieve its goal.
Other manufacturing data also indicate that manufacturing efficiency and  product quality continue to improve.
The amount of time spent on out-of-station work averaged 5 hours per  aircraft in 2015. This is a reduction of 88 percent since 2014.
The time spent on scrap, rework, and repair in the sixth production lot  averaged around 8,800 hours per aircraft. This is a reduction of 19  percent from the prior lot.
Non-conformances averaged around 3,900 per aircraft in the sixth  production lot. This is consistent with the prior lot.
Engineering design changes remained the same. In 2015, changes  averaged 23 per month, the same as in 2014.
Although it has improved, Lockheed Martin’s supply chain continues to  deliver parts late to production, resulting in inefficiencies and requiring  workarounds. Since 2014, there has been a 53 percent reduction in part  shortage occurrences. In 2015, there were a total of 269 less severe  shortages, and 89 most severe shortages on average per month (see  figure 7). The severity of part shortages is measured in four categories,  category 1 being the least severe, and category 4 and above being the  most severe with those shortages requiring a major workaround or work  stoppage.
According to Lockheed Martin and F-35 program officials, parts continue  to be delivered late largely because of late contract awards and because  the supply base is not yet capable of handling large quantities. We found  in April 2015 that inefficiencies related to limited supply base capabilities  could be exacerbated if this trend continues as production increases.
This continues to be a risk to the program. Lockheed Martin officials  stated they have a number of initiatives aimed at improving supplier  performance, including conducting additional oversight of some suppliers  and assisting some suppliers with developing corrective action plans. As  a result, Lockheed Martin officials believe the performance of some key  suppliers has improved over the last year.
section_title: Engine Deliveries Ahead of Contract but Efficiency Challenges Remain
paragraphs: Overall, the delivery rate of the engine manufacturer, Pratt & Whitney,  increased from 27 in 2011 to 42 in 2015. A total of 218 engines have  been delivered to date. In 2015, Pratt & Whitney delivered nearly half of  the engines to DOD ahead of contract requirements. The labor hours  required to assemble an F-35 engine decreased quickly and has  remained relatively steady since engine number 70 was delivered. Pratt &  Whitney officials largely attribute this improvement to lessons learned by  the contractor on previous fighter aircraft engine programs, such as the F- 22. Figure 8 illustrates the trend in labor hours required to build the F-35  engine, also known as the F-135. According to Pratt & Whitney data, few  additional labor hour reductions are expected; therefore, the contractor is  looking for other ways to gain more manufacturing efficiency.
Other Pratt & Whitney manufacturing metrics indicate that production  efficiency and quality have remained relatively steady.
Scrap, rework, and repair costs have remained steady at around 1.8  percent per engine. Difficulty manufacturing one of the engine rotor  blades—a hollow blade design—has driven much of the scrap and  rework costs in the engine program over the last year. However, Pratt  & Whitney officials have changed the blade design to a solid design  that is easier to produce. The solid blade is expected to decrease  scrap and rework costs.
Engineering design changes are relatively low and continue to  decrease. Only 31 of 175 major design changes remain to complete  the engine development program. A majority of these are scheduled  to be implemented in 2016.
According to Pratt & Whitney officials, their supply base does not  currently have the capacity to support maximum production rates. This  poses risk as the F-35 program plans to significantly increase production  rates over the next five years. To mitigate this risk, Pratt & Whitney is  pursuing the potential to have multiple suppliers for some engine parts,  known as dual-sourcing, which they believe will help increase  manufacturing capacity within the supply chain. According to Pratt &  Whitney officials, this approach may also lead to competitive pricing,  provide production stability, and mitigate the risks posed by  underperforming suppliers. In addition, Pratt & Whitney is conducting  production reviews of its supply chain and is managing supplier quality  initiatives to address shortfalls, according to officials.
section_title: Reliability and Maintainability Progress Continue but Not at Expected Rates
paragraphs: Although the program has made progress in improving system-level  reliability and maintainability, some metrics continue to fall short of  program expectations in several key areas. For example, as shown in  figure 9, while the metrics in most areas were trending in the right  direction, the F-35 program office’s own assessment indicated that as of  August 2015 the F-35 fleet was falling short of reliability and  maintainability expectations in nine of 19 areas. As of August 2015, the F- 35 fleet had only flown a cumulative total of 35,940 hours. The program  has time for improvement as the ultimate goals for these reliability and  maintainability metrics are to be achieved by full system maturity, or  200,000 cumulative flight hours across the fleet. The program currently  has a number of projects planned to further increase reliability.
Similarly, although engine reliability improved significantly in 2015, the  engine was still not performing at expected levels. In 2014, Pratt &  Whitney data indicated that engine reliability—measured as mean flight  hours between failure (design controllable)—was very poor and we  reported in April 2015 that the engine would likely require additional  design changes and retrofits. While Pratt & Whitney has implemented a  number of design changes that have resulted in significant reliability  improvements, the F-35A and F-35B engines are still at about 55 percent  and 63 percent, respectively, of where the program expected them to be  at this point. Program and contractor officials continue to identify ways  to further improve engine reliability.
In addition, average aircraft availability—the percentage of F-35 aircraft  capable of performing missions at a given time—was around 50 percent  when DOD had expected it to be 60 percent as of December 2015.  According to the office of the Director of Operational Test and Evaluation  (DOT&E) aircraft availability must improve significantly before initial  operational testing can begin. In a December 2015 memorandum,  DOT&E also noted that extensive modifications to operational test aircraft  are required and will not be completed in time to start initial operational  testing in 2017 as currently planned. Program officials stated they are  working to accelerate aircraft upgrades to support initial operational test  and evaluation.
section_title: DOD’s Approach to Managing Follow-on Modernization and Plans for Purchasing Future Lots of Aircraft Have Oversight Implications
paragraphs: The program is facing key decisions that have transparency and oversight  implications. DOD plans to manage F-35 follow-on modernization,  formerly known as follow-on development, as part of the existing program  baseline and not as a separate program which we have seen before. This  approach does not align with best practices and will likely hinder  transparency and oversight. In addition, the F-35 program is exploring the  potential for using a single contract to purchase multiple lots of future  aircraft—known as a block buy approach—which has potential benefits  and risks.
subsections: section_title: F-35 Follow-on Modernization Approach Will Likely Hinder Transparency and Oversight
paragraphs: Due to evolving threats and changing warfighting environments, DOD has  begun planning and funding the development of new F-35 capabilities,  known as follow-on modernization, but DOD’s current plan for managing  the development of these new capabilities may limit transparency and  oversight. The current F-35 development program is projected to end in  2017, when Block 3F developmental flight testing is complete, at a total  development cost of $55.1 billion. The first increment of follow-on  modernization, known as Block 4, is expected to add new capabilities and  correct deficiencies of nine capabilities carried over from the current  development program such as the prognostics health management  system down-link and communication capabilities. Although the  requirements are not yet final and no official cost estimate has been  developed for Block 4, DOD’s fiscal year 2017 budget request indicates  that the department expects to spend nearly $3 billion on these  development efforts over the next 6 years (see figure 10).
With development costs of this magnitude, the Block 4 program would  exceed the statutory and regulatory thresholds for what constitutes a  major defense acquisition program (MDAP), and it would be larger than  many of the MDAPs in DOD’s current portfolio. However, in August 2015,  the Under Secretary of Defense for Acquisition, Technology, and  Logistics issued an Acquisition Decision Memorandum directing the F-35  program office to manage Block 4 development under the existing F-35  acquisition program baseline and not as a separate incremental  acquisition program. As a result, DOD will not hold a Milestone B review  and will not establish a new baseline or business case. Therefore, DOD  will not be required to separately account for cost, schedule and  performance progress to Congress with regular, formal reports.
In preparation for F-35 Block 4 modernization, DOD is currently  conducting activities typical of a program preparing to begin system  development—including requirements definition and preliminary design— and is planning to award a new development contract for Block 4 in the  third quarter of fiscal year 2018. DOD policy indicates that the timing of  this contract award would usually initiate a Milestone B review for typical  programs of such magnitude. A Milestone B review would set in motion  oversight mechanisms including an acquisition program baseline; Nunn- McCurdy unit cost growth thresholds; and periodic reporting of the  program’s cost, schedule, and performance progress. These mechanisms  form the basic business case and oversight framework to ensure that a  program is executable and that Congress and DOD decision makers are  informed about the program’s progress. Best practices recommend an  incremental approach in which new development efforts are structured  and managed as separate acquisition programs and that a business case  should match requirements with resources—proven technologies,  sufficient engineering capabilities, time, and funding—before undertaking  a new product development. Because DOD does not yet have approved  requirements and is not planning to hold a Milestone B review, its  approach for Block 4 modernization will not require the program to have  such important reporting and oversight mechanisms in place.
We are concerned with DOD’s approach largely because of a similar case  we reported on in March 2005. In that report we found that the Air Force  was managing its multi-billion dollar F-22 modernization efforts as part of  the program’s existing acquisition baseline and had not established a  knowledge-based business case. We recommended that the Air Force  structure and manage F-22 modernization as a separate acquisition  program with its own business case—matching requirements with  resources—and acquisition program baseline. However, the F-22  baseline and schedule were not immediately adjusted to reflect the new  timeframes and additional costs and funding of the baseline development  and modernization effort were comingled. As a result, the content, scope,  and phasing of capabilities changed over time and it appeared that the F- 22 program was fraught with schedule delays and cost overruns. The  comingling of cost and schedule information reduced transparency and  Congress could not distinguish between increased costs associated with  the original baseline funding and increased costs associated with  modernization funding. As shown in table 2, the F-22 modernization  program was less complex than the proposed F-35 Block 4 development  but the F-22 program’s approach still resulted in poor acquisition  outcomes. Eventually, the department separated the F-22 modernization  program from the baseline program with a Milestone B review, in line with  our recommendation, which increased transparency and better facilitated  oversight. The department has the opportunity to apply similar lessons  learned to the F-35 Block 4 program.
section_title: Proposed Future Procurement Plan Has Benefits and Risks
paragraphs: In an effort to reduce procurement costs, the F-35 program office has  begun exploring the potential benefits and risks of using what the  program has called a block buy contracting approach. Currently, the  program purchases aircraft under separate annual contracts that are  negotiated on an annual basis. Program officials stated they are  considering seeking specific legal authority from Congress that would  enable them to enter into a 3 year contract to purchase three lots of  aircraft, although funding would still be authorized and appropriated by  Congress annually.
The F-35 block buy contracting approach under consideration does have  a number of potential benefits. For example, block buy contracting would  allow the program to purchase parts for all three lots of aircraft at the  same time, which could result in cost savings. By purchasing supplies in  economic quantities, Lockheed Martin and Pratt & Whitney estimate that  8 percent and 2.3 percent cost savings, respectively, could be achievable.  Program officials believe that block buy contracting can also enhance  program and supply chain stability by providing assurance that quantities  and the program’s ramp-up is nearing and steady work will continue. This  stability could help address the supply base’s delivery issues.
While the F-35 block buy contracting approach could result in cost  savings and other benefits, it can present oversight challenges. Our  analysis of the Navy’s block buy contract for the Littoral Combat Ship  (LCS) indicates that the contract could affect Congress’s funding  flexibility. For example, the LCS contract states that a failure to fully fund  the purchase in a given year would mean that the contract is subject to  renegotiation. This could result in the government paying more for the  remaining ships. The F-35 block buy plan is still under consideration and  the specific terms and conditions of the contract are not yet defined, nor  has the specific statutory authority the program might seek been enacted.  However, if the F-35 block buy contract contains similar provisions to  those in the LCS contract, Congress’s ability to make funding changes  could be similarly affected. Program officials noted that they are  examining prior block buys, like the LCS, to identify lessons learned and  looking for ways to reduce risk to the government.
Reducing costs for a program of the F-35’s size is clearly desirable.  However, adding an F-35 block buy to DOD’s portfolio of contracts with  explicit or potential long-term commitments could further affect  Congress’s funding flexibility. As can be seen in figure 11, long-term  contracts, such as block buys and multiyear contracts, will consume 30  percent of DOD’s fiscal year 2016 budget and if the F-35 block buy  contract was included as a long-term agreement, such agreements would  comprise nearly half of DOD’s budget.
section_title: Conclusions
paragraphs: The F-35 development program is nearing completion and aircraft  manufacturing continues to improve. While much of the remaining  developmental flight testing will be challenging, and some additional  discoveries are likely, the program has mitigated many of the technical  risks that we have reported on over the past several years. However, the  program is not without risks. Performance issues with ALIS and new  issues with the ejection seat and F-35C wing structures pose ongoing  risks. Going forward, the program will continue to experience affordability  and oversight challenges. DOD still expects that beginning in 2022 it will  need more than $14 billion a year on average for a decade to procure  aircraft. It is unlikely that the program will be able to receive and sustain  such a high level of funding over this extended period, especially given  DOD’s competing resources such as the long range strike bomber and  KC-46A tanker. While a block buy can offer savings and stability, how the  contract terms are developed will be an important consideration so as not  to affect congressional funding flexibility, especially when considering that  nearly a third of DOD’s acquisition budget is already covered by multiyear  commitments. Further congressional oversight challenges are presented  because of DOD’s plan to manage Block 4 under the current acquisition  program baseline and because key reporting requirements and oversight  mechanisms will not be initiated. Best practices recommend an  incremental approach in which new development efforts are structured  and managed as separate acquisition programs with their own  requirements and acquisition program baselines. Without an acquisition  program baseline and regular reporting on progress, it will be difficult for  Congress to hold DOD accountable for achieving F-35 Block 4 cost,  schedule, and performance goals.
section_title: Matter for Congressional Consideration
paragraphs: To enhance program oversight and accountability given that DOD does  not plan to modify its acquisition strategy and hold a Milestone B decision  review for the F-35 follow-on modernization program, Congress should  consider directing the Secretary of Defense to hold a Milestone B review  and manage F-35 Block 4 as its own separate and distinct major defense  acquisition program with its own acquisition baseline and regular cost,  schedule, and performance report to Congress.
section_title: Recommendations for Executive Action
paragraphs: In order to ensure that proper statutory and regulatory oversight  mechanisms are in place and to increase transparency into a major new  investment in the F-35 program, we recommend that the Secretary of  Defense hold a Milestone B review and manage F-35 Block 4 as a  separate and distinct Major Defense Acquisition Program with its own  acquisition program baseline and regular cost, schedule, and  performance reports to the Congress.
section_title: Agency Comments and Our Evaluation
paragraphs: DOD provided us with written comments on a draft of this report. DOD’s  comments are reprinted in appendix II. DOD also provided technical  comments, which were incorporated as appropriate.
DOD did not concur with our recommendation to hold a Milestone B  review and manage F-35 Block 4 follow-on modernization as a separate  and distinct major defense acquisition program. DOD stated that it views  Block 4 as a continuation of the existing F-35 acquisition program, which  it believes is the department’s most closely managed system. DOD went  on to explain that it plans to use existing F-35 oversight mechanisms like  regularly scheduled high-level acquisition reviews to manage its Block 4  efforts. In addition, the department noted that it is exploring ways to  provide further transparency into the cost, schedule, and performance  progress of Block 4, like establishing separate Block 4 budget lines,  instituting contract cost performance reporting, and developing an  independent cost estimate.
While we recognize that DOD policy provides flexibility to manage  programs in different ways, and we would encourage DOD to manage  Block 4 efficiently, the management approach should not sacrifice  transparency or oversight. As noted in this report, DOD is currently  conducting activities typical of a program preparing to begin system  development including requirements definition and preliminary design,  and expects to award a new development contract for Block 4 in fiscal  year 2018. DOD expects Block 4 modernization to develop and deliver 80  new capabilities and 17 weapons that were not part of the program’s  original acquisition baseline. In its fiscal year 2017 budget request, DOD  has identified the need for nearly $3 billion over the next 6 years for  development of these new capabilities. We continue to believe that a  development effort of this magnitude should be established as a major  defense acquisition program—as defined in statute and DOD policy—with  a Milestone B review and a separate and distinct business case and  acquisition program baseline. This would make the new program subject  to key statutory oversight mechanisms—including Nunn-McCurdy unit  cost growth thresholds—and DOD would be required to provide regular  cost, schedule, and performance reports to Congress. If Block 4 is  managed as a distinct program with a separate baseline, it would be  easier for Congress and DOD decision makers to track program-specific  cost and schedule progress. A hypothetical $1 billion cost increase in  Block 4 illustrates the difference in cost reporting and oversight. While a  $1 billion cost increase is significant, it would represent growth of less  than 1 percent if tracked against the current F-35 program baseline,  which is currently about $400 billion. That same cost increase, if tracked  against the $3 billion funding estimate reflected in DOD’s budget request  for Block 4, would be more visible, representing a 33 percent cost  increase. This is not the first time DOD has been faced with a decision  like this. As noted in this report, the Air Force’s F-22 modernization  program began in a similar situation. However, the Air Force eventually  chose to hold a Milestone B review for F-22 modernization and manage it  as a separate and distinct acquisition program, which increased  transparency and better facilitated oversight. Therefore, we continue to  believe that our recommendation is valid and as such are making a  matter for congressional consideration.
We are sending copies of this report to the appropriate congressional  committees, the Secretary of Defense, and Under Secretary of Defense  for Acquisition, Technology, and Logistics.  In addition, the report is  available at no charge on the GAO website at http://www.gao.gov.
If you or your staff have any questions about this report, please contact  me at (202) 512-4841 or sullivanm@gao.gov. Contact points for our  Offices of Congressional Relations and Public Affairs may be found on  the last page of this report.  GAO staff who made key contributions to this  report are listed in appendix IV.
section_title: Appendix I: Prior GAO Reports on F-35 Joint Strike Fighter and Department of Defense (DOD) Responses and Subsequent Actions
subsections: section_title: Estimated Development Costs Development Length Aircraft unit cost Key program event $34.4 Billion 10 years $69 Million
paragraphs: Start of system  development and  demonstration approved.
Primary GAO  Conclusions/Recommendation  Critical technologies needed for  key aircraft performance elements  are not mature. Program should  delay start of system  development until critical  technologies are mature to  acceptable levels.
DOD response and  actions   DOD did not delay start of  system development and  demonstration stating  technologies were at  acceptable maturity levels  and stated it will manage  risks in development.
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  was balanced between  cost, schedule and  technical risk.
Program sets in motion  plan to enter production in  2007 shortly after first flight  of the non-production  representative aircraft.
The program was entering  production with less than 1  percent of testing complete. We  recommended the program delay  investing in production until flight  testing shows that the Joint Strike  Fighter performs as expected.
DOD partially concurred  but did not delay start of  production because it  believed the risk level was  appropriate.
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 were  demonstrated.
DOD did not concur and  stated that the program  had an acceptable level of  concurrency and an  appropriate acquisition  strategy.
DOD implemented a Mid- course Risk Reduction Plan  to replenish management  reserves from about $400  million to about $1 billion by  reducing test resources.
We found the new plan increased  risks and DOD should revise it to  address concerns about testing,  management reserves, and  manufacturing. We determined  that the cost estimate was not  reliable and recommended the  need for a new cost estimate and  schedule risk assessment.
DOD did not revise the risk  plan or restore testing  resources, stating that they  will monitor the new plan  and adjust it if necessary.  Consistent with a report  recommendation, a new  cost estimate was  prepared, but DOD did not  conduct a risk and  uncertainty analysis.
The program increased the  cost estimate and added a  year to development but  accelerated the production  ramp-up. An independent  DOD cost estimate (JET I)  projected even higher costs  and further delays.
We concluded that moving  forward with an accelerated  procurement plan and use of cost  reimbursement contracts was 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 and  conduct a schedule risk  analysis. The program  reported completing the  first schedule risk  assessment with plans to  update semi-annually. The  Department announced a  major program reducing  procurement and moving  to fixed-price contracts.
The program was  restructured to reflect  findings from a 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.
Costs and schedule delays  inhibited the program’s ability to  meet needs on time. We  recommended the program  complete a full comprehensive  cost estimate and assess  warfighter and IOC requirements.  We suggested that Congress  require DOD to tie annual  procurement requests to  demonstrated progress.
DOD continued  restructuring, increasing  test resources and  lowering the production  rate. Independent review  teams evaluated aircraft  and engine manufacturing  processes. Cost increases  later resulted in a Nunn- McCurdy breach. Military  services are currently  reviewing capability  requirements as we  recommended.
Restructuring continued  with additional development  cost increases, schedule  growth, further reduction in  near-term procurement  quantities, and decreased  the rate for future  production. The Secretary  of Defense placed the  Short-takeoff Vertical  Landing variant on a two- year probation; decoupled  STOVL from the other  variants; and reduced  STOVL production plans for  fiscal years 2011 to 2013.
We concluded that the  restructuring actions were positive  and if implemented properly,  should lead to more achievable  and predictable outcomes.  Concurrency of development, test,  and production was substantial  and provided risk to the program.  We recommended DOD maintain  funding levels as budgeted;  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. DOD  lifted STOVL probation  citing improved  performance.  Subsequently, DOD further  reduced procurement  quantities, decreasing  funding requirements  through 2016. The initial  independent software  assessment began and  ongoing reviews were  planned to continue  through 2012.
The program established a  new acquisition program  baseline and approved the  continuation of system  development, increasing  costs for development and  procurements and  extending the period of  planned procurements by 2  years.
Extensive restructuring placed the  program on a more achievable  course. Most of the program’s  instability continued to be  concurrency of development, test,  and production. We  recommended that the Cost  Assessment Program Evaluation  office conduct an analysis on the  impact of lower annual funding  levels; and the program office  conduct an assessment of the  supply chain and transportation  network.
DOD partially concurred  with conducting an  analysis on the impact of  lower annual funding levels  and concurred with  assessing the supply chain  and transportation network.
The program continued to  move forward following a  new acquisition program  baseline in 2012. In doing  so, the program  incorporated positive and  more realistic restructuring  actions taken since 2010  including more time and  funding for development  and deferred procurement  of more than 400 aircraft to  future years.
The program was moving in the  right direction but must fully  validate design and operational  performance and at the same time  make the system affordable. We  did not make recommendations to  DOD in this report.
DOD agreed with GAO’s  observations.
The services established  initial operational  capabilities dates in 2013.  The Marine Corps and Air  Force are planning to field  initial operational  capabilities in 2015 and  2016, respectively, and the  Navy plans to field its initial  capability in 2018.
Delays in developmental flight  testing of the F-35’s critical  software may hinder delivery of  the warfighting capabilities to the  military services. We  recommended DOD conduct an  assessment of the specific  capabilities that can be delivered  and those that will not likely be  delivered to each of the services  by their established initial  operational capability dates.
DOD concurred with our  recommendation and  officials stated they are in  the process of conducting  the assessment.
DOD was developing  several plans and analyses  that will make up its overall  F-35 sustainment strategy,  which was expected to be  complete in fiscal year  2019.
The annual F-35 operating and  support costs were estimated to  be considerably higher than the  combined annual costs of several  legacy aircraft. DOD had not fully  addressed several issues that  have an effect on affordability and  operational readiness. Operating  and support cost estimates may  not be fully reliable. GAO  recommended that DOD develop  better informed affordability  constraints; address three risks  that could affect sustainment,  affordability, and operational  readiness; and take steps to  improve the reliability of its cost  estimates.
DOD concurred with all but  one recommendation and  partially concurred with the  recommendation to  conduct uncertainty  analysis on one of its cost  estimates, stating it already  conducts a form of  uncertainty analysis.
Since the 2012 re- baselining, DOD has made  changes to its F-35  procurement plans on an  annual basis. The program  also competed with other  high priority DOD programs  for funding. In 2013 and  2014 DOD deferred a  number of aircraft,  extending the length of the  program, and increasing  funding liability in the  future.
The consistent changes in F-35  procurement plans indicate that  the analysis done to support the  program’s 2012 baseline did not  accurately account for future  technical risks or funding realities.  We recommended DOD conduct  an affordability analysis of the  current procurement plan that  reflects various assumptions  about technical progress and  funding availability.
DOD concurred with the  recommendation and  stated that it accomplishes  an analysis of the  program’s current  procurement plans with  various assumptions about  technical progress and  funding availability every  year as it conducts reviews  for the budget process.
section_title: Appendix II: Scope and Methodology
paragraphs: To assess the program’s cost and affordability, we reviewed total program  funding requirements using the December 2015 Selected Acquisition  Report. We used these data to project annual funding requirements  through the expected end of the F-35 acquisition in 2038. We also  compared the December 2015 Selected Acquisition Report to prior  Selected Acquisition Reports to identify changes in cost and quantity. We  obtained life-cycle operating and support cost through the program’s 2015  Selected Acquisition Report and projections made by the Cost Analysis  and Program Evaluation office.
To assess the program’s remaining development and testing we  interviewed officials from the program office, contractors, Lockheed  Martin and Pratt & Whitney. We obtained and analyzed data on flights  and test points, both planned and accomplished during 2015. We  compared test progress against the total program plans to complete. In  addition, we interviewed officials from the F-35 program office, Lockheed  Martin, Pratt & Whitney, and the Director, Operational Test and  Evaluation office to discuss development test plans, achievements, and  test discoveries. We also collected relevant information from the program  office, Lockheed Martin, Pratt & Whitney, and Department of Defense test  pilots regarding the program’s technical risks including the helmet  mounted display, autonomic logistics information system, carrier arresting  hook, structural durability, ejection seat, and engine.
To assess ongoing manufacturing and supply chain performance we  obtained and analyzed data related to aircraft delivery rates and work  performance data through the end of calendar year 2015. These data  were compared to program objectives identified in these areas and used  to identify trends. We reviewed data and briefings provided by the  program office, Lockheed Martin, Pratt & Whitney, and the Defense  Contract Management Agency in order to identify issues in manufacturing  processes. We discussed reasons for delivery delays and plans for  improvement with Lockheed Martin and Pratt & Whitney. We also toured  Lockheed Martin’s manufacturing facility in Ft. Worth, Texas and Pratt &  Whitney’s manufacturing facility in Middletown, Connecticut. We collected  and analyzed data related to aircraft quality through December 2015. We  collected and analyzed supply chain performance data and discussed  steps taken to improve quality and deliveries with Lockheed Martin and  Pratt & Whitney. We also analyzed reliability and maintainability data and  discussed these issues with program and contractor officials.
To assess future modernization and procurement plans, we discussed  cost and manufacturing efficiency initiatives, such as the block buy  approach, with contractor and program office officials to understand  potential cost savings and plans. To assess the program’s follow-on  modernization plans we discussed the program’s plans and with program  office officials. We reviewed the fiscal year 2016 and fiscal year 2017  budget requests to identify costs associated with the effort. We collected  and analyzed information regarding capability and oversight plans for the  development effort. We also reviewed and analyzed best practices  identified by GAO and reviewed relevant DOD policies and statutes.
We assessed the reliability of DOD and contractor data by reviewing  existing information about the data, and interviewing 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 2015 to April 2016 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.
section_title: Appendix III: Comments from the Department of Defense
section_title: Appendix IV: GAO Contact and Staff Acknowledgments
subsections: section_title: GAO Contact
section_title: Staff Acknowledgments
paragraphs: In addition to the contact name above, the following staff members made  key contributions to this report: Travis Masters, Assistant Director; Peter  Anderson, Kurt Gurka, Kristine Hassinger, Jillena Roberts, Megan Setser,  and Roxanna Sun.
section_title: Related GAO Products
paragraphs: F-35 Sustainment: DOD Needs a Plan to Address Risks Related to its  Central Logistics System. GAO-16-439. Washington, D.C.: April 14, 2016.
F-35 Joint Strike Fighter: Preliminary Observations on Program Progress.  GAO-16-489T. Washington, D.C.: March 23, 2016.
F-35 Joint Strike Fighter: Assessment Needed to Address Affordability  Challenges. GAO-15-364. Washington, D.C.: April 14, 2015.
F-35 Sustainment: Need for Affordable Strategy, Greater Attention to  Risks, and Improved Cost Estimates. GAO-14-778. Washington, D.C.:  September 23, 2014.
F-35 Joint Strike Fighter: Slower Than Expected Progress in Software  Testing May Limit Initial Warfighting Capabilities. GAO-14-468T.  Washington, D.C.: March 26 2014.
F-35 Joint Strike Fighter: Problems Completing Software Testing May  Hinder Delivery of Expected Warfighting Capabilities. GAO-14-322.  Washington, D.C.: March 24, 2014.
F-35 Joint Strike Fighter: Restructuring Has Improved the Program, but  Affordability Challenges and Other Risks Remain. GAO-13-690T.  Washington, D.C.: June 19, 2013.
F-35 Joint Strike Fighter: Program Has Improved in Some Areas, but  Affordability Challenges and Other Risks Remain. GAO-13-500T.  Washington, D.C.: April 17, 2013.
F-35 Joint Strike Fighter: Current Outlook Is Improved, but Long-Term  Affordability Is a Major Concern. GAO-13-309. Washington, D.C.: March  11, 2013.
Fighter Aircraft: Better Cost Estimates Needed for Extending the Service  Life of Selected F-16s and F/A-18s. GAO-13-51. Washington, D.C.:  November 15, 2012  Joint Strike Fighter: DOD Actions Needed to Further Enhance  Restructuring and Address Affordability Risks. GAO-12-437. Washington,  D.C.: June 14, 2012.
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.
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.
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.