What happened
On the morning of January 12, 2003, a Robin DR 400-180, registration F-GNNN, was being prepared for a flight at Lille Lesquin aerodrome. The weather conditions were notably cold, with a temperature of -7 °C and a dew point of -8 °C.
Approximately forty-five minutes before the scheduled departure, the pilot attempted to start the engine to allow for warm-up. The pilot followed a memorized startup procedure previously used for DR 4-120 and DR 400-180 aircraft, which involved manually turning the propeller 10 times, performing 3 fuel injections, and setting the throttle to a 1 to 1.5 cm position before engaging the starter.
After an initial failed attempt and a second failed attempt, the engine successfully started following a third fuel injection. Shortly after ignition, the pilot observed flames emerging from the lower section of the engine and noticed a burning smell inside the cabin. The pilot immediately shut down the engine, closed the fuel valve, and cut the electrical power. After evacuating the aircraft, the pilot contacted emergency services. Small flames were observed burning near the nose gear strut attachment, which extinguished before firefighters arrived.
The investigation
The investigation focused on the sequence of events leading to the fire and the specific procedures used during the startup. The investigators examined the pilot's reliance on a memorized procedure rather than the specific protocols outlined in the aircraft's flight manual. The investigation also reviewed the different startup checklists used by the flying club, noting that the pilot's method did not align with the manufacturer's requirements for cold weather operations.
Findings
- The engine fire was caused by the use of a standard startup procedure that was inappropriate for the cold weather conditions present on the day of the incident.
- The pilot relied on a memorized procedure from previous experience with different aircraft models rather than following the specific cold-weather startup instructions provided in the Robin DR 400-180 flight manual.
- The engine fire resulted in damage to the air intake duct.