A consequential decision about the F-35 Joint Strike Fighter program is expected this month, with the U.S Air Force expected to choose whether to replace the Pratt & Whitney F-135 engine in future models of the F-35A with the XA100 engine, developed by GE Aviation as part of the USAF’s Advanced Engine Transition Program (AETP.)
The F-35 is a single-engine aircraft designed for deployment for ground attack and combat missions by the U.S. Air Force, U.S. Marine Corps, and U.S. Navy. It is the largest U.S. defense program, but it is the focus of much scrutiny and criticism for production and maintenance costs.
Currently there is a considerable backlog in the F-135 supply chain, leaving dozens of USAF F-35s unavailable for service.
In the 2022 National Defense Authorization Act the U.S. Congress directed the three service branches that operate the F-35 to consider replacing the F-135 with either the GE XA-100 or Pratt & Whitney XA-101 engine (another product of the AETP) as soon as 2027.
If the USAF decides to replace the F-135 engine with one of the AETP products that choice may not be matched by the USMC or USN, or by the various foreign defense forces that also participate in the F-35 program. The program requires each participant to assume the costs for customization to the basic aircraft design.
Another complicating factor may be that the AETP engines as of now are not compatible with the F-35B aircraft – the short takeoff and vertical landing variant adopted by the USMC – because of that aircraft’s specific exhaust system.
USAF Secretary Frank Kendall, who spoke about his pending decision in recent public comments, admitted he preferred “the AETP solution” because it would provide the F-35A jets with greater range and more electrical power for several advanced weapons systems.
”“I am hopeful that we will have” an AETP decision in the fiscal 2024 budget, Kendall said. “I think we need to make some decision about the future of the F-35’s engine and get on with it.”
