Lockheed Martin is running out of space to store undelivered F-35 Joint Strike Fighters as the jets’ upgrade effort remains behind schedule, the U.S. Government Accountability Office said in a report released Thursday.
Furthermore, the F-35 program’s testing capacity is stretched thin and will worsen once the Technology Refresh 3 software upgrade and the Block 4 update are ready, GAO found.
TR-3 involves a slate of improvements for the aircraft, such as improved cockpit displays, better computer memory and more processing power. TR-3 is needed before another group of more in-depth upgrades, known as Block 4, can be installed on the F-35. Block 4 will allow the jet to carry more weapons and provide upgrades to its electronic warfare capabilities.
But TR-3 is overdue due to problems with its software and delays in the production of key parts. Test officials told the government watchdog that TR-3′s software remains “unstable,” almost a year after deliveries were supposed to start.
Since July 2023, the Pentagon has refused to accept delivery of the newest F-35s that will be enabled with TR-3. Most F-35s are built at Lockheed’s factory in Fort Worth, Texas. When a new jet rolls off the company’s production lines, they are stored at that facility until the permanent hardware kits for TR-3 and its software is ready.
GAO did not publish the number of mostly finished F-35s awaiting delivery in its report, at the Pentagon’s request.
But on Wednesday, Rep. Rob Wittman, R-Va., chairman of the House Subcommittee on Tactical Air and Land Forces, told reporters that within months more than 100 jets could be “stacked up on the tarmac — unacceptable.”
GAO said storing so many critical, brand-new jets in one place is risky because some or all could be damaged. The parking space at Lockheed’s facilities is dwindling, the watchdog noted, and the company needs a backup plan if it runs out.
In a statement to Defense News, Lockheed said TR-3 is one of its top priorities and that it will work with the government’s F-35 Joint Program Office and industry partners to put GAO’s recommendations in place as appropriate.
Lockheed also said it has enough secure infrastructure and capacity to park all F-35s until delivery, but would not go into details, citing security concerns.
The F-35 Joint Program Office said in an email that the next iteration of TR-3′s software will start flight tests later this month, and that the military could start accepting aircraft as soon as late July.
“The JPO remains committed to working with our industry partners to deliver the F-35 to our warfighters to ensure they can fight and win when called to do so,” JPO spokesman Russell Goemaere said.
The Hill’s take
Earlier this week, the House Armed Services Committee released its proposed fiscal 2025 National Defense Authorization Act, which would cut 10 jets from the Pentagon’s proposed F-35 procurement next year, bringing its buy down to 58.
Lawmakers say that would save roughly $1 billion, funds that would then go toward ensuring TR-3 and the jets work properly.
The bill would also prevent the military from accepting 10 of those remaining jets until the Pentagon certifies to lawmakers that several problems are fixed.
Wittman on Wednesday said lawmakers are “deeply concerned” about the delays and called them “grossly delinquent.”
He also described the F-35 as “the critical linchpin in our tactical aircraft capability,” adding that the program and Lockheed have to get the jet and its upgrades right — especially with the Air Force’s planned drone wingmen, known as collaborative combat aircraft, on the way. TR-3 and Block 4 upgrades will be needed to take the most advantage of those unmanned capabilities, he said.
The F-35 Joint Program Office and Lockheed are now working on a partial version of the TR-3 software. This truncated TR-3 software is intended to allow the jets to work well enough so the military can conduct check flights and accept delivery.
Even then, TR-3 jets would only be able to conduct training flights, and would not be ready to fly combat missions until 2025.
Test jet shortages
The F-35′s testing capacity is also falling short and could hamper the program’s ability to get TR-3 and Block 4 upgrades right, GAO said.
The program now has four test F-35s, all of which are more than a decade old, GAO found. Those jets frequently break and are short on spare parts needed to get them back in the air, the report said. The test jets’ troubles are so severe that there have been times when three were down for maintenance simultaneously, GAO added.
The only thing saving the F-35′s testing fleet from falling completely behind is that TR-3 and other software development is behind schedule, GAO said. But once TR-3 and Block 4 software get back on track, the report added, the current testing fleet could be severely strained, as more flights will be necessary.
Four more test F-35s are in the works, with an expected completion date of 2026, GAO said. But those will be regular F-35s, modified after production with instruments that allow them to conduct basic developmental weapons tests.
These modified jets would have to use some workarounds, and would be unable to test external weapons stations under their wings due to a lack of instruments, the report said. This will likely present a particular problem for the F-35B, which has a greater need to test wing-mounted weapons.
Nine more test jets — intended to be developmental test aircraft from the start — are also planned to replace the current fleet, GAO said. The Pentagon is so far moving forward with procuring six of those jets, the report noted, but they won’t be ready for test flights until between 2029 and 2034. And the current replacement plan will now leave the F-35 program without any test aircraft in 2028 and 2029, GAO said.
While speaking to reporters Wednesday, Wittman said the billion dollars saved by cutting F-35 purchases would help fund an integrated software laboratory, digital twin testing, and more test aircraft to try to get improvements such as TR-3 ready. Expanding the F-35′s test capacity is long overdue, he added, and is coming back to bite the program now.
“All those things are [capabilities] that should have been done years ago and haven’t been done,” Wittman said. “That’s why we’re so far behind where we are today.”
Megan Eckstein contributed to this report.
Stephen Losey is the air warfare reporter for Defense News. He previously covered leadership and personnel issues at Air Force Times, and the Pentagon, special operations and air warfare at Military.com. He has traveled to the Middle East to cover U.S. Air Force operations.
