According to a newly released report issued by the United States Air Force Aircraft Accident Investigation Board, maintenance personnel caused severe damage to the $14,000,000 engine of an F-35A plane by neglecting to follow established protocol.
The incident occurred on March 15, 2023, at Luke Air Force Base in Arizona while the plane was under service by the 62d Aircraft Maintenance Unit, 56th Aircraft Maintenance Squadron.
The maintenance unit was installing metering plugs into the augmenter throttle valve pressure tube assembly following a December 2022 incident in which the CP12 tube assembly ruptured on an F-35B. This incident caused significant damage to the plane. As a precaution, the entire F-35 fleet was undergoing preventative maintenance.
Following the installation of the metering plug, the engine of the plane was run to allow the maintenance team to monitor the system for leaks. According to the report, prior to engaging the engine, one member of the maintenance unit conducted the required tool inventory check, noting a missing flashlight.
Another maintenance squadron member inspected the engine with a flashlight. Following this inspection, this squadron member placed the flashlight on the edge of the engine intake. This member did not conduct a routine inventory check, which resulted in the flashlight being left on the intake.
While the engine was in operation, no warning signs were noted from the cockpit that the engine had encountered foreign material. However, at the end of the test run, maintenance personnel became aware of abnormal sounds from the engine compartment. The engine of the F-35A is estimated to have suffered $3,933,106 in damage.
According to the report, each member assigned to conduct the modifications was fully qualified for the duties they were to perform. USAF Colonel Sean S. Brammer-Hogan, President of the Accident Investigation Board, noted the failure of all squadron members to follow inventory protocol resulted in the costly accident.
“I find, by a preponderance of evidence, that the mishap was caused by MM1 not executing a complete inlet inspection and failing to conduct a tool kit inventory prior to engine run operations. MM1 failed to clear the inlet of foreign objects after completing the required inspections for an engine run after they exited the aircraft inlet,” the report stated. “Failure to complete checklist tasks resulted in a flashlight being left inside the inlet. The flashlight was ingested into the engine during the engine run and caused the damage to the engine.”
According to Task and Purpose, it’s unclear whether the team will face any military discipline over the incident. Captain Scarlett Trujillo, Air Education and Training Command Spokesperson, declined to release information.
“Any administrative actions taken regarding the F-35 incident on 15 March are not releasable,” Trujillo said.