On September 27, 1993, a Beech A36 (registration N80010) was involved in an aviation accident near Houston, TX. Investigators recorded the probable cause as: A cross-threaded output line on the engine-driven fuel pump, which allowed fuel to leak into the engine compartment. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
During engine start with high boost pump, flames emerged from the engine compartment. Pilot and passenger evacuated before aircraft engulfed. Investigation found cross-threaded output line on engine-driven fuel pump, which had been re-installed earlier that day.
Accident Overview
During engine start, the pilot engaged the high boost pump and observed flames rising from the engine compartment toward the door. The pilot and passenger were able to exit the aircraft before it became fully engulfed in flames.
Investigation Findings
Post-accident examination revealed that the output line on the engine-driven fuel pump was cross-threaded. This condition allowed fuel to leak into the engine compartment, where it ignited during the start sequence.
Maintenance History
The engine-driven fuel pump had been removed and re-installed earlier on the same day. The mechanic who performed the post-maintenance run-up noted that the engine ran roughly unless the boost pump was set to low. The mechanic did not inform anyone of this difficulty until after releasing the aircraft for flight and following the accident.
Probable cause
A cross-threaded output line on the engine-driven fuel pump, which allowed fuel to leak into the engine compartment.