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The F-35 Will Now Exceed $2 Trillion As the Military Plans to Fly It Less

Posted on May 16, 2024

The F-35 Lightning II Joint Strike Fighter is the Department of Defense’s most ambitious weapons program and plays a crucial role in DOD’s ability to meet current and future U.S. national security goals. At the same time, the F-35 has been plagued by mounting costs and delays resulting in what some have called a staggering price tag of more than $2 trillion over several decades.

In March, the fighter jet marked an important milestone — “full-rate production,” generally the point when development reaches an acceptable level of performance and reliability to start building more of them, faster. F-35s have already been in production at or near full rate for several years. At the same time, the military services that fly the F-35 (the Air Force, Marines, and Navy) plan to use it less.

What’s going on with the F-35? Today’s WatchBlog post looks at our two new reports about challenges with modernizing the F-35 and its rising costs and declining use.


Photo of the F-35 joint strike fighter landing.


F-35 faces production issues and modernization delays that increase costs 

Technology is always changing—even when it comes to the most advanced weapon systems.

DOD is pursuing a $16.5 billion modernization effort that will provide the F-35 with new capabilities through both hardware and software upgrades. These include radar enhancements, weapons, and technology to avoid aircraft collisions. Some of these capabilities depend on technology updates that were planned for delivery last July. But they are delayed because of software stability issues.

Around the same time (last May), the F-35 program was in the early stages of planning to modernize the fighter jets’ engine and thermal management system. This effort is needed to provide the F-35 with additional power and prevent systems, such as the radar, from overheating. But as these efforts were taking off, we reported concerns that the military hadn’t fully defined the power and cooling requirements that the engine and related systems will need to support future capabilities.  In addition, DOD had not assessed the costs and some of the technical risks of these new engine efforts. These are just two examples of modernization delays that have led to increased costs for the F-35.

What does this all mean? It means that while the F-35 has reached this important milestone—achieving full-rate production—the military continues to discover technical risks that cost it and the taxpayer more money. We previously made recommendations to help the F-35 program address these challenges, but DOD has only implemented some of them.

Operating and support costs continue to rise despite the military planning to use the F-35 less

Across the military there are about 630 F-35s—with plans to buy about 1,800 more. The Air Force, Marines, and Navy each have their own versions of the F-35.

Projected costs for sustaining the F-35s have continued to rise from $1.1 trillion in 2018 to $1.58 trillion 5 years later (a 44% increase). This increase is in part due to the extension of the service life of the aircraft from 2077 in 2018 to 2088 in 2023. This also has occurred despite DOD:

Reducing some costs associated with sustaining the F-35 aircraft. Over the past 10 years DOD has undertaken several cost savings efforts and continues to look for new ways to reduce costs. For example, DOD has taken actions to improve the reliability and maintainability of parts on the aircraft. The F-35 program estimates that its initiatives have reduced sustainment costs by about $84 billion over the lifetime of the program.

Planning to fly the F-35 less. Over the course of the last couple of years, the Air Force and Navy have also reduced their projected annual flying times by 19% and 45% respectively. In part because of this reduction in flying, the services are now projecting they will meet most of their affordability targets. Affordability targets are the amount of money they project they can afford to spend per aircraft per year for operating the aircraft.

Learn more about these changes and more in our podcast with GAO’s Diana Maurer:

Spending more now to cut costs later. Efforts like modernizing the F-35’s engine are intended to increase the longevity of parts and reduce costs associated with more frequent maintenance of the engine if it were not modernized. But, as discussed above, there are many ways these efforts could be improved to reduce costs now.

In addition to costs, we found that F-35 repair times have been slow, and there has been a growing backlog of components needing repair. This has reduced the jets’ availability for missions.

Big picture. The F-35 is meant to give U.S. military defense an advantage as well as be the future of these efforts. That’s why it is so important for the F-35 to be both affordable and available to the military when needed. 

Learn more about our work on F-35 modernization and sustainment by checking out our recent reports.

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