The U.S. Air Force says it was a flight control system malfunction, which caused an F/A 22 Raptor to crash at Nellis Air Force Base, Nevada late last year.
The Air Force is releasing the official findings of the accident investigation this week.
The aircraft’s three rate sensor assemblies which measure acceleration in the jets, pitch, roll and yaw, failed.
Without the sensor information Raptor is unable to fly. Apparently, the investigation says, the pilot shot down the F/A 22’s engines for maintenance servicing.
He left an auxiliary power source turned on believing that would be enough to keep the rate sensors operating, but the one-second-power interruption was enough to cause the sensors to malfunction.
The Air Force grounded its entire F/A 22 Raptor fleet following the crash. That grounding included the 13 Raptors assigned to Tyndall Air Force Base.
Tyndall is the training home for Raptor pilots.