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F-35 Joint Strike Fighter: Action Needed to Improve Reliability and Prepare for Modernization Efforts

GAO-19-341 Published: Apr 29, 2019. Publicly Released: Apr 29, 2019.
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Fast Facts

DOD plans to spend over $270 billion to buy more than 2,000 F-35 aircraft over the next 26 years.

In this year's review, among other things, we found the F-35 program:

Made slow, consistent progress on reliability and maintainability. But, it has not met 4 of 8 targets, which suggests the aircraft will be less reliable and more costly to maintain.

Will start a modernization effort—now estimated at $10.5 billion—without a complete business case and while still developing key technologies. This increases the risk of cost increases and delays.

We made 5 recommendations, including that the program clarify and improve its reliability plans.

F-35 Aircraft

Photo of 4 F-35s flying over snow-covered mountains

Photo of 4 F-35s flying over snow-covered mountains

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Highlights

What GAO Found

The F-35 program has made slow, sustained progress in improving the aircraft's reliability and maintainability (R&M). The F-35 aircraft (see figure) are assessed against eight R&M metrics, which indicate how much time the aircraft will be in maintenance rather than operations. Half of these metrics are not meeting targets. While the Department of Defense (DOD) has a plan for improving R&M, its guidance is not in line with GAO's acquisition best practices or federal internal control standards as it does not include specific, measurable objectives, align improvement projects to meet those objectives, and prioritize funding. If the R&M requirements are not met, the warfighter may have to settle for a less reliable and more costly aircraft than originally envisioned.

Image of F-35 Aircraft

Image of F-35 Aircraft

In 2019, the F-35 program will start modernization efforts—estimated to cost $10.5 billion—for new capabilities to address evolving threats, without a complete business case, or a baseline cost and schedule estimate. Key documents for establishing the business case, such as an independent cost estimate and an independent technology assessment, will not be complete until after the program plans to award development contracts (see figure).

Key F-35 Modernization Business Case Documents to Be Completed After Contract Awards

Image of F-35 Aircraft

Without a business case—consistent with acquisition best practices—program officials will not have a high level of confidence that the risk of committing to development has been reduced adequately prior to contract awards. Moving ahead without a business case puts F-35 modernization at risk of experiencing cost and schedule overruns similar to those experienced by the original F-35 program during its development.

Why GAO Did This Study

In 2018, DOD sent an F-35 aircraft to its first combat mission and started initial operational testing. DOD now plans to spend over $270 billion to buy more than 2,000 F-35 aircraft over the next 26 years. Since 2011, GAO has found the need for more attention to the F-35's R&M performance to achieve an operationally suitable system.

The National Defense Authorization Act for Fiscal Year 2015 included a provision for GAO to review the F-35 acquisition program until it reaches full-rate production. This is GAO's fourth report under this provision. This report assesses, among other objectives, (1) the program's progress in meeting R&M requirements (such as mission reliability) and (2) its plans for spending on new capabilities. GAO reviewed and analyzed management reports and historical test data; discussed key aspects of F-35 development with program management and contractor officials; and compared acquisition plans to DOD policies and GAO acquisition best practices.

Recommendations

GAO is making five recommendations to DOD, including that it identify specific and measurable R&M improvement objectives, align improvement projects, and prioritize resources to meet them. In addition, DOD should complete its business case for modernization before beginning additional development efforts. DOD did not concur with this recommendation, but did concur with the R&M recommendations and plans to take action to address them.

Recommendations for Executive Action

Agency Affected Recommendation Status
Department of Defense The Secretary of Defense should ensure that the F-35 program office assesses whether the Operational Requirements Document (ORD) R&M targets are still feasible and revise the ORD accordingly. (Recommendation 1)
Closed – Implemented
DOD concurred with our recommendation and stated that it would review its Reliability & Maintainability (R&M) requirements and possibly revise them. In late 2019, the F-35 Program Executive Officer (PEO) developed an initiative to clearly identify what, if any, revisions DOD should make to the ORD. In July 2021, the joint program office reported they developed a "180 day sprint initiative" to more clearly identify what, if any, requirements exist which require an ORD revision. In March 2024, upon assessing the R&M requirements for F-35, DOD determined the original requirements were valid and that the F-35 program is expected to achieve them in 2027. This action meets the intent of our recommendation.
Department of Defense The Secretary of Defense should ensure that the F-35 program office, as it revises its Reliability and Maintainability Improvement Program (RMIP), identifies specific and measurable R&M objectives in its RMIP guidance. (Recommendation 2)
Closed – Implemented
DOD concurred with our recommendation and stated that it would update its RMIP guidance. In late 2019, DOD reported that a revised RMIP will be delivered to program leadership for approval. In September 2020, the program revised the F-35 RMIP Instruction, which noted specific and measurable reliability and maintainability objectives. In a subsequent report to Congress, the program office noted that the revised RMIP goals are to meet reliability and maintainability performance metrics, meet sustainment performance metrics outlined the F-35 Life Cycle Sustainment Plan, increase F-35 availability and mission capability, and decrease F-35 life cycle costs. The RMIP also implements projects for design change, retrofit/ modification, and process improvements to increase reliability and maintainability of all components of the F-35 enterprise.
Department of Defense The Secretary of Defense should ensure that the F-35 program office, as it revises its RMIP, identifies and documents which RMIP projects will achieve the identified objectives of the RMIP guidance. (Recommendation 3)
Closed – Implemented
DOD concurred with our recommendation and stated that it would update its RMIP guidance. In late 2019, DOD reported that a revised RMIP will be delivered to program leadership for approval. In September 2020, the program revised the F-35 RMIP Instruction, which notes specific and measurable reliability and maintainability (R&M) objectives. In a subsequent report to Congress, the F-35 program office confirmed that the revised RMIP plan identifies and documents which RMIP projects will achieve R&M objectives.
Department of Defense The Secretary of Defense should ensure that the F-35 program office prioritizes funding for the RMIP. (Recommendation 4)
Closed – Implemented
DOD concurred with our recommendation and stated that it would plan for reliability and maintainability funding going forward. For example, the program dedicated $40 million for RMIP projects in fiscal year 2020. This was an increase over the fiscal year 2019 funding of $7 million for RMIP projects and shows a prioritization for RMIP funding. In August 2021, the program reported they requested an additional $36.8 million for FY 22 RMIP projects. Furthermore, a new funding structure for RMIP projects was implemented in fiscal year 2020. This new approach ensures that RMIP projects are funded through completion, rather than on an annual basis until funding ran out as it was under the prior RMIP funding mechanism.
Department of Defense The Secretary of Defense should ensure that the F-35 program office completes its business case, at least for the initial Block 4 capabilities under development, before initiating additional development work, to include: an independent cost estimate; an approved test and evaluation master plan which addresses resources, aircraft shortfalls, and funding; and an independent technology readiness assessment. (Recommendation 5)
Closed – Implemented
DOD did not concur with this recommendation, citing that the F-35 program office has adequate cost, schedule, and technical maturity knowledge to begin the development of initial Block 4 capabilities. Though these items were completed after DOD conducted additional development work, as of July 2020, the F-35 program office has completed an independent cost estimate, an approved test and evaluation master plan, and an independent technology readiness assessment.

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Topics

Aircraft acquisition programsAircraft maintenanceBest practicesCost and scheduleCost estimatesCost overrunsDefense acquisition programsDefense capabilitiesInternal controlsJoint strike fighterMilitary readinessNational defenseOperational testingSchedule slippages