Air Force will launch the Engine Core Upgrade for the F-35

The Air Force has decided not to pursue a new engine for the F-35A in its fiscal 2024 budget request because the new engine was simply too expensive to develop, Air Force Secretary Frank Kendall said at the March 10 budget briefing. As a result, the service’s FY24 budget request seeks $245 million to fund an engine upgrade offered by Pratt.

The problem largely came down to the fact that while there was “some discussion” about fitting the new engine with the Navy’s carrier-launched F-35C variant, getting it to work with the Marine’s short take-off and vertical landing (STOVL) F-35B variant was “going to be very, very difficult, if not impossible.” The lack of commonality risked disrupting the engine’s shared international supply chain, a hallmark for the program and a strong selling point for international customers of the aircraft. 

The Department of Defense had been considering re-powering the fighter with thrusters known as “adaptive engines,” (AETP= Adaptive Engine Transition Program) which use a third-party airflow to enable more fuel-efficient flight during cruise and greater thrust during cruising. combat, to provide greater power and thermal management to the F -35 also in view of the program to upgrade the aircraft with the suite of capabilities known as Block 4.

The Air Force’s verdict rests on “the combination of affordability and the fact that the Air Force, with the F-35A variant, was the only service that was really seriously interested in AETP,” Kendall said.

Kendall said ECU (Engine Core Upgrade) would “provide acceptable levels of increased performance for all three services,” adding that although AETP will be discontinued, the program “has set the basis” for the service’s Next Generation Adaptive Propulsion (NGAP) engine that will power the secretive Next Generation Air Dominance system.