F-35 jet plane
A F-35 is pictured at Luke Air Force base in Glendale, Arizona - where the accident occurred in March 2023
A $14 million fighter jet engine was irreparably damaged after an engineer left a flashlight inside the engine, sealed it up and turned it on, a military investigation has revealed.

The accident happened at Luke Air Force base in Glendale, Arizona, in March 2023, on a plane with the 56th Fighter Wing.

The F-35 jet was undergoing a routine check of its propulsion system, and a metering plug was inserted into an engine fuel line.

Aircraft Maintenance Unit
The accident happened at this base, with the 62d Aircraft Maintenance Unit, 56th Aircraft Maintenance Squadron
The addition of the plug was mandated across the Air Force's F-35 fleet to fix an issue discovered after a mishap with the fuel system in December 2022. The F-35 was 'one of the last aircraft that needed to be completed,' according to the report.

The three-person engineering team from the 62d Aircraft Maintenance Unit, 56th Aircraft Maintenance Squadron then sealed up the plane, having inserted the metering plug, and tested the engine.

They fired the engines in the hangar, and let the plane run for 13 minutes.

None of the warning sirens sounded, and the test appeared to be carried out as normal.

But when they shut the engine off, the engineers heard a clanging sound.

'Following the shutdown,' the report reads, one of the maintainers 'completed the post operations servicing inspection and identified damage to the blades of the engine.

'He reported the engine damage to the maintenance expeditor and stated: 'I believe I just ingested a flashlight.''

The damage to the engine was calculated at $4 million, meaning the entire $14 million engine needed to be scrapped.

The Air Force Aircraft Accident Investigation Board found that the engineers failed to follow correct procedures and do a tool check, to make sure that all their tools were accounted for before starting the engine.

They also failed to use the standard procedure of attaching to themselves all the items they may need.

No one was injured in the incident.

Luke officials would not say if any of the maintainers involved had faced punishment for the mishap.

'Any administrative actions taken regarding the F-35 incident on 15 March are not releasable,' said Capt. Scarlett Trujillo, spokesperson for the Air Education and Training Command, when asked by military news website Task & Purpose.

The Air Force says each member of the maintenance team was current and qualified to accomplish all the tasks.