Incident Overview
Description
Mohawk Flight 40 took off from Elmira at 14:39 EDT for a flight to Washington, DC. At 14:44 the aircraft was cleared to climb to FL160. Eyewitnesses observed the aircraft a little later near Blossburg when large sections of the tail separated from the aircraft in flight, after which fire and smoke emitted from the tail as the aircraft dove into the ground. PROBABLE CAUSE: “The loss of integrity of empennage pitch control systems due to a destructive in-flight fire which originated in the airframe plenum chamber, fueled by hydraulic fluid, progressed up into the vertical tail fin. The fire resulted from engine bleed air flowing back through the malfunctioning nonreturn valve and an open air delivery valve, through the auxiliary power unit in a reverse direction, and exiting into the plenum chamber at temperatures sufficiently high to cause the acoustics linings to ignite.”
Primary Cause
Destructive in-flight fire originating from hydraulic fluid, engine bleed air, and reverse flow from an auxiliary power unit within the airframe plenum chamber, resulting in ignition of the airframe acoustics linings.Destructive in-flight fire originating from hydraulic fluid, engine bleed air, and reverse flow from an auxiliary power unit within the airframe plenum chamber, resulting in ignition of the airframe acoustics linings.Share on:
