What happened
On 16 June 2019, a Robin DR400-140B, registration F-GBIA, was conducting a cross-country flight from Deauville Normandy aerodrome toward Saint Cyr l’École. The aircraft, operated by Aéroclub de Boulogne Billancourt, was carrying a pilot and one passenger.
While flying on the downwind leg of the traffic pattern at approximately 700 feet, the pilot reported engine problems to the tower. The engine experienced several misfires before stopping completely. Due to the low altitude, the pilot opted not to attempt a restart and instead performed a forced landing in a nearby wheat field. During the landing roll, the aircraft struck a green wire fence that was obscured by vegetation, causing the nose gear to fail and resulting in the destruction of the aircraft. Both occupants evacuated the aircraft safely without injury.
The investigation
The BEA examined the engine, the fuel system, and the flight logs to determine the cause of the power loss. The investigation included a test of the engine on a test bench, which showed nominal operation. The mechanical and electric fuel pumps, as well as the carburetor, were also inspected and found to be functional with no identifiable faults.
Regarding the fuel system, investigators found that the main tank contained approximately 50 liters of fuel, while the range extension tank was empty. The transfer valve was operational, and the distribution of fuel confirmed that the transfer process from the extension tank to the main tank had been activated during the flight. However, the investigators noted that there was no fuel present in the hose between the mechanical pump and the carburetor.
Findings
- The engine and all fuel system components, including pumps and the carburetor, showed no mechanical or structural defects.
- The fuel analysis revealed no contamination or anomalies.
- Based on estimated fuel consumption, the amount of fuel remaining in the main tank may have reached the critical 10-liter threshold, where engine power is no longer guaranteed unless in level flight.
- The engine shutdown is consistent with the unpriming of the fuel system.
- The pilot's inability to see the fence during the landing roll was due to the fence being obscured by the height of the wheat and its green color.