ACC: Improperly Assembled Engine Control Caused April F-16 Crash

A Washington, D.C., Air National Guard F-16 crashed in April shortly after takeoff from JB Andrews, Md. An Air Combat Command investigation found the crash was caused by an improperly installed main engine control system. Air Force photo from Accident Investigation Board report.

An improperly assembled main engine control caused a Washington, D.C., National Guard F-16C to crash in April near JB Andrews, Md., the Air Force announced Thursday.

The pilot, assigned to the 121st Fighter Squadron at Andrews, was able to eject safely after steering the F-16C toward an unpopulated field.

The mishap occurred during a four-ship F-16 formation out of Andrews. The aircraft were flying a routine, basic surface attack training mission, according to an Air Combat Command release.

During takeoff, the aircraft experienced an “uncommanded engine acceleration,” followed by a loss of thrust. The pilot followed steps for a low altitude engine failure and jettisoned external wing fuel tanks and then extinguished an engine fire by placing the throttle to “cut-off,” according to ACC. The engine was already damaged to the point where it was unusable.

The aircraft was too far from a recovery airfield to be able to glide safely to land. The pilot directed the aircraft toward an open field and ejected. The aircraft crashed in a wooded area and was destroyed, at a loss of about $22 million. The two tanks crashed near houses in Clifton, Md.

The Accident Investigation Board found that the main engine control was missing a required 600-degree training ring and the anti-rotation pin. The misassembled differential pilot valve caused the F-16’s main engine control to incorrectly meter an abnormally high fuel flow to the engine. This in turn caused “severe” engine over speed, over temperature, an engine fire, and catastrophic engine failure, according to ACC.

Read the full AIB report.