Since there are 272 F-35A jets in the Air Force’s inventory, nearly 15 percent are without an engine.
41 US Air Force (USAF) F-35A Lightning II stealth fighters are currently without engines according to the most recent data, top officials told Congress on Jul. 13, 2021, Air Force Magazine reports.
41 of the fifth-generation fighters don’t have an engine due to maintenance issues, while 56 F135 power modules are currently being repaired at Tinker Air Force Base, Okla, acting Assistant Secretary of the Air Force for Acquisition, Technology, and Logistics Darlene Costello said speaking before the House Armed Services subcommittee on tactical air and land forces.
Since there are 272 F-35A jets in the Air Force’s inventory, nearly 15 percent are without an engine.
Lt. Gen. Eric T. Fick, F-35 program executive officer, confirmed Costello’s numbers.
Rep. Donald Norcross (D-N.J.), however, expressed discomfort about providing funds to buy more F-35s while a significant number of jets are already in the service in need of engines.
“The idea of rolling [out] a new aircraft with an engine while others are sitting—and I’m hearing the numbers and we can argue over which ones they are—but [that is] certainly something that is a real concern,” Norcross said.
During the July 13 hearing, other representatives expressed concerns about the F-35 program hitting on familiar topics of high sustainment costs and delayed production while discussing the 2022 budget request for fixed-wing tactical and training aircraft programs.
Rep. Mike Turner (R-Ohio) asked if the military was looking at alternative engine options to keep sustainment and operation costs down since according to a Government Accountability Office finding fewer than four percent of F-35 engines have been delivered on time.
“Engine costs in sustainment are challenging,” Fick acknowledged, while also noting that no F-35 delivery has been delayed because of an engine. “And as we rapidly approach the 2,000-hour first scheduled engine removal, we will start to bear those costs in the sustainment of the air system. And we also know that we have begun to reach a flat or a flatter spot in the learning curve relative to the overall cost of production engines.
“When I couple that with the notion that post-the current Block 4 content, we will likely need increased power and increased thermal management capability from our propulsion system, I think that the need to look for options from a propulsion system perspective is present.”
In February, USAF Chief of Staff Gen. Charles Q. Brown Jr. said that the USAF has the largest and “most mature” F-35 fleet, and is seeing F135 engines “failing a little faster in certain areas,” due to their “high use rate” and heavy deployment pace, given their relative newness in the fleet.
Because of these issues, the USAF F-35 Demo Team, assigned to the 388th Fighter Wing at Hill Air Force Base (AFB), Utah, has been forced to reduce appearances this year: the Air Combat Command (ACC) that controls the team cut the number of 2021 shows by eight performances (about one-third) towards the end of January to ensure the flying doesn’t aggravate a worsening service-wide shortage of engines.
Brown explained that options are being looked at in maintenance and depot to mitigate the problem, noting he has three- and four-star generals studying the issue.
But he said that one big solution could simply be to use the F-35 less.
“I want to moderate how much we’re using those aircraft,” he said. “You don’t drive your Ferrari to work every day, you only drive it on Sundays. This is our ‘high end’ [fighter], we want to make sure we don’t use it all for the low-end fight … We don’t want to burn up capability now and wish we had it later.”
With more than 40,000 lbs. of thrust, the Pratt & Whitney F135 engine is the most powerful fighter engine ever produced and it is the heartbeat of the F-35. Evolved from the proven F119 engine that powers the F-22 Raptor, the F135 powers all three variants of the F-35 Lightning II.

Photo credit: Lockheed Martin