Incident Sequence
Shortly after takeoff from Seattle-Tacoma International Airport, the flight crew observed a loss of power from the right engine and decided to return for a precautionary landing. During the approach, after the landing gear was extended, a large fire was discovered in the right engine nacelle. Following touchdown, the crew lost directional control and all braking capability. The aircraft departed the left side of runway 16L after the left power lever was moved to flight idle. The first officer advised the tower that the aircraft was out of control. The aircraft then rolled onto the ramp area, where it struck a runway designator sign, ground equipment, and jetways B7 and B9. The aircraft was subsequently destroyed by fire.
Investigation Findings
Investigation revealed that during an overhaul of the right engine, the high-pressure fuel filter cover was improperly installed. This improper installation was not detected during the company's subsequent installation of the engine on the aircraft. The improperly installed cover allowed a massive fuel leak, which resulted in a fire within the right engine nacelle. The fire and associated explosion caused the loss of engine center access panels, which reduced the effectiveness of the fire suppression system and allowed damage to other systems.
Probable Cause
The National Transportation Safety Board determined the probable cause of this accident was the improper installation of the high-pressure fuel filter cover, which permitted a massive fuel leak and subsequent fire in the right engine nacelle. The improper installation likely occurred at the engine manufacturer; however, the failure of airline maintenance personnel to detect and correct the improper installation contributed to the accident. Also contributing was the loss of the right engine center access panels from a fuel explosion, which negated the fire suppression system and allowed a hydraulic line burn-through that resulted in a total loss of airplane control on the ground.