What happened
Following a refueling stop at the Saint-Mathias aerodrome in Quebec, a Piper PA-23 was preparing for a flight to Beloeil. During the takeoff roll, the pilot performed a standard five-minute engine run-up. As the aircraft climbed to approximately three feet above the ground, the instructor noticed smoke emerging from the rear of the right engine.
Following the instructor's command to land immediately, the pilot brought the aircraft back to the gravel runway. Due to the limited 2,000-foot length of the runway, the aircraft could not be stopped on the pavement and ended up in a ditch at the end of the runway. The two occupants evacuated the aircraft safely, and while no injuries were reported, a fire broke out under the right nacelle. Local firefighters arrived to extinguish the flames, which had been fed by leaking fuel.
The investigation
Investigators examined the wreckage and identified the fire's origin within the right nacelle, specifically in the area containing the fuel selector, fuel filter, and auxiliary fuel pump. The fire caused extensive damage, destroying the wing spar and consuming the fuel filter entirely.
Technical inspections of the electrical and hydraulic systems ruled out electrical short circuits or hydraulic leaks as the cause. However, the investigation focused on the integrity of the fuel pump installation. It was discovered that the auxiliary fuel pump was secured by only one bolt, whereas two were required. Additionally, the fitting connecting the fuel supply to the pump was not sufficiently tightened.
Findings
- The fire originated from a fuel leak at the connection between the auxiliary fuel pump and the fuel filter.
- The auxiliary fuel pump was improperly secured to the aircraft structure, as one of its two required retaining bolts was missing.
- The fitting for the fuel filter was not tightened adequately, creating a potential leak path.
- The instructor's presence and observation allowed for the immediate termination of the takeoff, preventing a more serious accident.