Undisclosed F-22 engine trouble prompted ongoing fleetwide hardware fix

By Michael Marrow / September 12, 2022

The Air Force has been quietly carrying out a fleetwide hardware fix for the F-22 Raptor after the aircraft logged several incidents due to a significant problem with the fighter’s dual F119 engines, Inside Defense has learned.

The issue has racked up nearly $23 million in damages for the service stemming from seven Class A engine mishaps -- the Defense Department’s most serious accident classification -- that spanned nearly a decade and prompted a retrofit effort beginning in 2019 that is slated to finish next year.

Officials won’t say what caused the problem, which hasn’t previously been reported by media outlets. Inside Defense first inquired about the issue in August after reviewing public Class A mishap data released by the Air Force Safety Center, which showed the seven engine mishaps occurred between 2012 and 2020, with the final one logged in the second quarter of 2020.

Air Combat Command spokeswoman Capt. Erica Feehan told Inside Defense that the mishaps caused no injuries and resulted in $22.9 million in damages. Citing a DOD policy that exempts certain safety information from disclosure, Feehan declined to elaborate on the cause, but said all seven mishaps stemmed from the same problem.

“The cause of the incidents was identified and Safety Risk Assessments were completed which determined operations could continue within acceptable safety standards while the Air Force worked through solutions,” Feehan said. “The Air Force is nearly finished incorporating the latest configuration hardware, which addresses the issue. The fleet has not experienced a similar Class A incident since May 2020.”

Integration of the new hardware into the entire fleet is now 92% complete, Feehan said, and is scheduled to conclude by May 31, 2023.

To be classified as such, a Class A incident must involve a fatality, permanent disability, more than $2.5 million in damages to government property, destruction of an aircraft or all the above, according to an overview of the mishap investigation process published by AFSEC.

The nearly $23 million in cumulative damages is a notable but relatively small sum for the Raptor’s estimated annual $2.3 billion in sustainment costs reported by the Government Accountability Office in June, which found the aircraft’s mission-capable rates have declined in recent years.

In a statement to Inside Defense, a spokesman for F119 engine manufacturer Pratt & Whitney said that during the summer of 2017, the company and the Air Force discovered an “engine-related issue” and “identified the root cause of the issue that same summer.” Pratt then began “ramping up production of a replacement component,” according to the spokesman, whose integration into the entire F119 fleet commenced in 2019.

Pratt also identified several aircraft “whose engine components were at higher risk due to environmental factors,” the spokesman said, though the adverse conditions were not specified. Those aircraft were then prioritized for the retrofit, which the spokesman said was achieved within approximately a year.

The spokesman added that the solution would have normally been reserved for regularly scheduled depot maintenance, but the fix was able to be implemented both in the field and in depot. Pratt provides F119 sustainment services at Tinker Air Force Base, OK.

ACC spokeswoman Alexi Worley told Inside Defense that “the cause of all seven mishaps was attributed to a failure of the same component,” but “it was determined during the Safety Risk Assessments that the root cause of this component failure was different between the initial event in 2012 and a later event in 2017. The configuration hardware currently being incorporated into all U.S. Air Force F-22 aircraft engines addresses all previous hardware failure modes and root causes.”

All pilots are briefed on the findings of Safety Investigation Boards, Worley added, and are trained to handle engine emergencies with procedures outlined in flight manuals.

The Air Force currently has 183 F-22s, the smallest fleet of fighters in the service’s inventory, with squadrons stationed at ACC’s headquarters at Joint Base Langley-Eustis, VA, along with others at bases in Alaska, Hawaii and Florida. In its fiscal year 2023 budget request, the service sought to scrap 33 block 20 F-22s to shift funds to the Next Generation Air Dominance program, but the request has encountered congressional opposition.

A government analyst familiar with DOD sustainment issues, who requested anonymity since they were not authorized to publicly discuss the matter, said in an interview with Inside Defense the problem was not particularly unusual given that complex weapon systems can have thousands of parts that are at risk of malfunctioning, but noted that any engine issues can pose a safety concern.

“This was not a red light blinking, like ‘planes are going to fall out of the sky’ sort of problem,” the analyst said, adding that “it looks like it was a yellow light bordering on red light.”

J.J. Gertler, who formerly served as the military aviation analyst with the Congressional Research Service, said in an interview with Inside Defense that changes to an entire fleet are “not unusual,” whether for worn-out components or upgrades, but remarked that the speed of the fix was atypical.

“Normally, if the Air Force is replacing a part across a fleet, it’s not a safety-of-flight issue, so it can be done whenever those aircraft were going to come in for depot service anyway,” Gertler said. “In this case, it was an accelerated process, because you didn’t want those parts staying on the airplane one minute longer than they had to.

“When you are scheduling a specific maintenance availability just to do one thing, that’s very unusual,” he added. “That’s what happened in this case, regardless of where it was done.”

For a fleetwide fix like this, congressional oversight is typically involved as well, either because a staffer on a relevant committee requested a briefing or the Air Force proactively provided one, Gertler said.

Raptor mishaps can appear more pronounced than other aircraft due to the fleet’s small size, which is greatly outnumbered by other platforms like the F-16. However, the limited number of F-22s is likely also a reason the engine problem had to be quickly addressed, according to Gertler.

“The F-22 fleet is so small, it’s even more important to the Air Force and the nation to resolve something like this quickly,” he said. “You can’t afford to have a significant number of airplanes down at any given moment. It doesn’t leave you with enough to do anything useful.”