The U.S. Department of Defense plans to award a major follow-on development contract for the F-35 Joint Strike Fighter in June 2019, about 10 months later than previously planned, according to a new report by the Government Accountability Office (GAO).

The slippage will give the F-35 program more time to finish its original, often-delayed development effort and “lay a more solid, knowledge-based foundation for modernization,” the GAO wrote in its report, released June 5. 

Maintenance staff inspect one of the 10 Luke AFB F-35s sent to Nellis AFB for a training deployment, April 15, 2015. Photo: U.S. Air Force.
Maintenance staff inspect one of the 10 Luke AFB F-35s sent to Nellis AFB for a training deployment, April 15, 2015. Photo: U.S. Air Force.

DoD is still refining many details for Block 4, the GAO noted. This month, the department intends to update the acquisition strategy and convene a high-level Defense Acquisition Board to determine when a request for proposals will be issued. In March 2019, DoD is scheduled to give Congress a report that makes a “full business case” for the follow-on work.

The GAO urged lawmakers to freeze Block 4 funding until they receive that business-case report, saying that caution is warranted to avoid repeating the mistakes of the initial, 17-year development phase. DoD’s fiscal year 2019 budget request includes $278 million for Block 4 development, whose total cost is expected to be billions of dollars.

“DOD requested funding for modernization over a year before the program has a business case for Block 4,” the GAO wrote. “This means that the program is asking Congress to authorize and appropriate funds for Block 4 without insight into its complete cost, schedule and technical baselines.”

The GAO said the Block 4 report should include an independent cost estimate, technology readiness assessments, a test and evaluation master plan, a system engineering plan, a preliminary design review and an approved acquisition strategy.