F-35 engine upgrade program to run out of money in June without FY-24 budget

By Vanessa Montalbano  / February 9, 2024

An ongoing engine modernization program for the F-35 Joint Strike Fighter will have to halt at the end of June if Congress isn't able to rectify a monthslong partisan divide over the fiscal year 2024 budget, Inside Defense has learned.

“The program continues to mitigate preliminary design risks,” Russell Goemaere, a spokesman for the F-35 Joint Program Office, said. “We believe, if there is no appropriation, we can use funding for existing work to cover contract costs through June 2024.”

Congress has been operating under three consecutive stopgap continuing resolutions for the first five months of the fiscal year as lawmakers haggle over a full budget. The back and forth is hamstringing the Air Force’s ability to kickstart new programs or put fresh money into modernizing weapon systems.

Under the current CR, which for the Defense Department will expire on March 8, the F135 Engine Core Upgrade is stuck with last year’s appropriation of $75 million, despite DOD asking for more than $400 million in 2024 to ensure its rapid progress.

Without an approved appropriations bill “all engine modernization efforts, to include the Engine Core Upgrade (ECU) and Power and Thermal Management Upgrade (PTMU), will be delayed,” Goemaere said.

It would ultimately “lead to a pause in engine modernization efforts. This would cause a significant delay in ECU and PTMU development and impact future warfighter capabilities,” he added.

The updated financial timeline comes after Pratt and Whitney, the maker of the engine, told reporters Tuesday that the F-35 ECU program remains on track for deliveries starting in 2029 and is “hitting all of our schedule milestones.”

Asked about how the lack of an FY-24 defense appropriations bill might impact the program’s progress or development, Pratt Vice President for the F135 program Jennifer Latka said, “We absolutely need the FY-24 budget approved . . . but I don’t think that our production cut-in date of 2029 is dependent on the CR right now.”

If Congress is unable to pass a budget by April 30, the Air Force alone stands to lose “$4.4 billion per quarter [from] things that we thought we were going to be able to do that we can’t” due to sequestration cuts, Lt. Gen. Richard Moore, deputy chief of staff for plans and programs, said during a Center for Strategic and International Studies event last month.

Under that scenario, the Defense Department’s overall budget would be reduced to 2023 spending levels minus 1%.

“Like all programs, the continuing resolution has the potential to have an impact. We have not worked through all the details if we had a sequestration scenario,” Latka said. “What I know now is that our schedule is on track, that we have identified funding to continue, and that’s not to say that that situation cannot change.”

In December testimony before the House Armed Services Committee, Program Executive Officer and Director for the F-35 Lightning II Program Air Force Lt. Gen. Michael Schmidt said funding for the ECU program would be stable through “February-ish,” but contended that after that point it risked running out of money.

Latka on Tuesday declined to offer an exact timeline of when ECU funds might run dry, saying “there’s a lot of different pieces of design that are progressing at different rates right now. So, we don’t have an exact date when the money runs out and the timer goes off.”

Still, the JPO is projecting June as the latest point in which work on the program can proceed without a final budget.

The ECU program was born out of a need for improved energy efficiency and higher performance as the stealth aircraft undergoes massive software and hardware modernizations, known as Block 4 and Technology Refresh 3.

The new electronic warfare capabilities brought on by those changes are already taxing the fighter’s current engine, causing it to run significantly hotter and for fewer hours.

Latka said the company will wrap up its preliminary design review in May and expects to complete the critical design review “in roughly the middle of 2025.” Pratt will then test the first upgraded engine by 2026 to kick off fielding in 2029, she said.

But even those dates are later than originally anticipated. Last year, Latka said the preliminary design review was planned for January 2024.

For its part, the JPO said: “The Preliminary Design Review (PDR) has not been delayed; it is event driven. We have added a senior level engineering and technical review to the schedule which will take place in the February/March timeframe. The JPO, in conjunction with our industry partner, continues to mitigate risk as we work toward the PDR.”