Event Description
Shortly after takeoff, during retraction of the landing gear and flaps, the number 1 engine low fuel pressure warning light illuminated. At approximately 400 feet above ground level (AGL), the flight crew heard a loud bang, followed by a number 1 engine fire warning indication. The crew shut down the affected engine and discharged both fire extinguishing bottles. They extended the landing gear using the alternate system and performed a no-flap emergency landing. Emergency brakes were used, but directional control was lost, causing the aircraft to veer off the side of the runway and come to a stop. The fire was extinguished by the time the aircraft stopped.
Examination Findings
Inspection of the number 1 engine area revealed a failed low fuel pressure warning switch snubber and fire damage to the engine, nacelle, and wheel well. Evidence indicated that during installation, the low fuel pressure warning switch snubber was torsionally deformed. This deformation led to fatigue cracking and subsequent failure of the snubber. Additionally, gaps in the firewall allowed leaking fuel (in the form of spray) to enter the hot section of the engine, where it ignited. This resulted in an explosion and fire. The fire propagation caused burning of wires leading to the number 1 standby hydraulic pump and ruptured a number 2 system hydraulic line.
Probable Cause
The low fuel pressure warning switch snubber failed due to torsional deformation during installation, leading to fatigue and failure. Gaps in the firewall allowed leaking fuel to enter the hot section and ignite, resulting in the explosion and fire.