An accident investigation board determined that a flight control system deficiency caused an F/A-22 Raptor aircraft mishap Sept. 28 near Edwards Air Force Base, Calif. The flight control system allowed the aircraft to exceed set angles of attack and G-force limits. The resulting aircraft damage is estimated at more than $3 million.

No fatalities, injuries or damage to private property resulted from the mishap, and the F/A-22 from the 411th Flight Test Squadron was able to land at Edwards.

The board found the primary cause of the mishap was a deficiency in the aircraft's flight control system, which provides aircraft stability, control and maneuvering agility.

The aircraft was flying a high-risk test mission with an F-16 Fighting Falcon. After encountering the F-16's jet wash, the Raptor experienced an unexpected and rapid pitch oscillation. The mission was to test air-to-air tracking scenarios to evaluate handling qualities with a configuration of two external fuel tanks.

The aircraft's load factor or G-force limits in this configuration were 7.33 and minus 0.5. During the test, the load factors ranged between 10.1 to minus 11.7.

The aircraft, one of the Air Force's first F/A-22s, is primarily a testing aircraft.

FMI: www.af.mil