Pentagon: F-35 engine upgrade to be funded by all jet customers, will be ready by FY30

Pentagon: F-35 engine upgrade to be funded by all jet customers, will be ready by FY30
F-35A at Reno Air Races Sept 2021

Maj. Kristin Wolfe, F-35A Lightning II Demonstration Team commander, performs an aerial maneuver during the Reno Air Races in Reno, Nev., Sept. 19, 2021. The demonstration team is based out of Hill Air Force Base, Utah. (U.S. Air Force)

WASHINGTON — The Pentagon expects that an engine upgrade offered by Pratt & Whitney for the F-35 Joint Strike Fighter will be ready to field in fiscal 2030 and that all customers — foreign and domestic — who fly the jet will pitch in to fund its development, according to a spokesperson for the F-35 Joint Program Office.

The projection to complete the engineering and manufacturing development phase and required testing is seven years from the start of the pre-Preliminary Design Review activities, which began in fiscal year 2022. Fielding is expected to begin soon thereafter, tentatively late in the first quarter or early in the second quarter of fiscal year 2030,” JPO spokesperson Chief Petty Officer Matthew Olay told Breaking Defense.

Olay explained that Pratt’s Engine Core Upgrade (ECU) will be available for the tri-variant F-35 fleet as soon as it’s ready, which will all be retrofitted once they come into depot. Future engines will also have the ECU applied when in production before being shipped to airframe manufacturer Lockheed Martin for integration, Olay said, adding that the JPO’s “intent is to execute per the cost share agreement across the partnership,” meaning that all members of the Joint Strike Fighter enterprise would contribute funding.

A detailed acquisition strategy is being formulated, Olay said, that when finalized will determine exact aspects like milestones and associated costs. However, he emphasized that “[f]unding and an implementation plan for fiscal year 2024 is contingent upon what is authorized and appropriated in the president’s budget for FY24.” (The recently unveiled budget, which is still likely to be changed by lawmakers, requests some $245 million in FY24 for the Air Force to fund the effort.)

Pratt executives have described the ECU as a modular enhancement to the company’s existing F135 powerplant. Jen Latka, F135 engine program vice president at Pratt, previously said the company’s ECU solution would be ready to field in 2028 and that it would cost about $2.4 billion to develop. The company did not respond today to questions about the apparent discrepancy with JPO’s timeline.

Officials had been weighing whether to develop a new, adaptive engine for the F-35 to provide greater power and cooling as the program looks to field a suite of upgrades for the fighter known as Block 4. Both the Air Force and the JPO conducted separate business case analyses (BCAs) for the engine decision, though their findings have not been made public. According to an Air Force spokesperson, the ECU will not be funded as as a separate program of record in the service’s budget request.

On Monday, the Air Force revealed that it would not be pursuing the new engine through the service’s Adaptive Engine Transition Program, in which Pratt and General Electric each had been developing adaptive powerplant prototypes since 2016. During a budget briefing with reporters, Air Force Secretary Frank Kendall said the service’s decision was driven by a prohibitive cost to develop the engine, combined with a lack of interest in fielding it among the Marines and Navy, who also fly F-35 variants.

RELATED: General Electric finishes testing adaptive engine, but will it power the F-35? 

On Wednesday, however, during a speech at the McAleese Defense Programs conference, Kendall seemed to express some reservations about the service’s approach, stating that while it was the “right decision” not to pursue an adaptive engine given the service’s “constraints,” it’s a decision he “worr[ies] about a little bit.”

“That would probably be something I would — if we had the opportunity to reconsider that — I think that would be something I’d like to have another shot at. Right now it’s unaffordable,” he told conference attendees.

During a subsequent scrum with reporters, Kendall said he was concerned about fuel efficiency for the F-35 fleet, pointing to “attractive” improvements in range and fuel efficiency an adaptive engine could deliver, but returned to it being an “affordability question.” And, Kendall said, going with the ECU plan that would be solely delivered by Pratt means that the F-35 program is “not going to be able to introduce competition as effectively.”

Still, when asked directly whether the Air Force would be willing to give an adaptive engine another go if Congress provided extra funds for development, Kendall indicated the service’s decision is final. 

“No, we’ve made our decision. We’re on a path and as I said, it’s a multi-billion dollar program and it’s a multi-year program. So putting some money in for one year doesn’t get you that. It just keeps it going and doesn’t really solve the problem,” he said.

The Air Force’s decision still needs approval from lawmakers, who could take alternative steps like forcing a new engine competition or funding both AETP and the ECU. As the services prepare to testify before Congress ahead of the FY24 budget request, where lawmakers stand will soon become clear.