What happened
On April 6, 2014, a Robin R3000-160, registration F-GKRB, was participating in a multi-leg general aviation flight. After completing the first two legs of the itinerary, the aircraft arrived at Bourg Ceyzériat aerodrome for refueling and a short break.
During the third leg of the flight, the second pilot attempted to start the engine. Following standard pre-start procedures, the pilot performed three or four fuel injections. When the engine failed to start, the pilot implemented the procedure for a flooded engine. While the engine briefly ran before stalling during the adjustment of the mixture control from full lean to full rich, a second start attempt triggered a fire. Witnesses on the apron observed flames emerging from the engine exhaust area and alerted the pilot. The crew immediately switched the magneto and battery contacts to the OFF position and evacuated the aircraft. A bystander used a portable powder extinguisher from the fueling station to suppress the flames.
The investigation
The investigation focused on the damage sustained by the aircraft and the pilot's actions during the startup sequence. The fire caused damage to the lower engine cowling near the exhaust, the magneto block, the electrical wiring, the air intake manifold, the air box, and the air filter.
Investigators also reviewed the pilot's experience and the procedures used. The pilot, who held a PPL(A) since 2010 with 145 total flight hours, noted that they had followed cold start procedures without first checking the engine oil temperature indicator.
Findings
- The primary cause of the fire was the ignition of fuel that had accumulated due to multiple fuel injections during the repeated startup attempts; this fuel likely ignited upon contact with hot engine or exhaust components.
- The failure to verify the engine temperature contributed to the pilot selecting the incorrect startup procedure for the engine's thermal state.