U.S. F-35s forward deploy to NATO’s eastern flank

Two U.S. Air Force F-35 Lightning II aircraft assigned to the 34th Fighter Squadron at Hill Air Force Base, Utah, arrive at Ämari AB, Estonia. (US Air Force)

WASHINGTON — Costs for the F-35 Joint Strike Fighter’s Block 4 modernization effort have grown 55 percent above the $10.6 billion baseline set five years ago, the Government Accountability Office reported this week — and the congressional watchdog says they lack information to determine exactly why.

“Since we last reported in April 2022, Block 4 estimated development costs increased by $1.4 billion, from $15.1 billion to a new total of $16.5 billion,” the GAO said in an expansive new report on the Joint Strike Fighter [PDF] published Tuesday. “The total increase to date is 55 percent more than what the program originally reported it would cost in 2018.”

A major driver of that cost growth, according to program officials interviewed by GAO, is the software suite’s burgeoning list of capabilities. A 2016 assessment estimated 66 capabilities for the fighter would be delivered by fiscal 2026, a number that has now risen to 80 to be delivered through FY29. Yet according to GAO, current records make it difficult to assess how much of that rising price tag stems from the addition of these capabilities compared to developmental woes for ones previously on the books.

“Program officials told us they attribute much of the Block 4 cost increases to its addition of new capabilities beyond the original Block 4 capabilities. We are unable to validate that view because the program’s cost reporting does not provide information on cost increases that occur during capability development for those original Block 4 capabilities or new capabilities added since 2018,” according to the report.

And even though the program has for years been required to submit reports to Congress on Block 4’s cost and schedule, that information is also lacking for full oversight, GAO found. If the Block 4 effort was managed as a separate program — a recommendation the GAO noted it had previously made, but was ignored on —  its 55 percent cost growth would have been enough to trigger a critical Nunn-McCurdy breach, where the defense secretary would have to submit a certification to stave off a termination by Congress.

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Many planned Block 4 capabilities are enabled by an upcoming hardware and software update known as Technology Refresh 3 (TR-3), which had its first flight test in January, about a year behind schedule due to delays caused by software instability, GAO said.

That test uncovered new issues, GAO found, though program officials determined the TR-3’s hardware was sufficient to support cutting it into production starting in February 2023. The first jet equipped with TR-3 is now scheduled for delivery in July, GAO said, leaving only six months between its first flight test and ensuring its software “is mature enough to be delivered to the military services.”

“An aircraft with TR-3 hardware is currently on the production line. TR-3 software is being tested and once validated will be installed on production aircraft,” F-35 Joint Program Office (JPO) spokesman Russ Goemaere said in a statement. “To help with the process, the JPO has added more aircraft to the testing pool. The goal is to deliver fully validated and approved TR-3 software to our warfighters.”

The Air Force has additionally chosen to defer production of 215 F-35As, GAO stated, stretching out planned deliveries by six years from 2046 to 2052 and increasing procurement costs by $13.4 billion. The JPO didn’t not immediately respond when asked why the deliveries were deferred.

“We are currently reviewing the report and will coordinate with the F-35 Joint Program Office and our F-35 industry partners to address the GAO recommendations,” F-35 prime contractor Lockheed Martin said in a statement. “The F-35 remains the cornerstone of the U.S. fighter fleet, currently deterring adversaries and providing a critical advantage for the nation and its global partners.”