What happened
On September 30, 2004, a Robin ATL aircraft, registration F-GFRA, was engaged in a flight from Péronne to Beauvais. After a brief stop in Péronne, the pilot departed alone at 18:15. Due to reduced visibility in the area, the pilot adjusted the flight path westward and descended to an altitude of 500 feet.
At approximately 18:35, while near Moreuil, the pilot attempted to climb but noticed the engine was not producing sufficient power, with the airspeed failing to exceed 110 km/h despite full throttle. The pilot subsequently diverted toward Amiens-Glisy aerodrome. While monitoring the airspeed indicator, the pilot failed to notice that the aircraft was losing altitude. At 18:55, realizing the aircraft could not clear a line of poplar trees, the pilot performed an emergency landing in a field in Hamelet. During the landing roll, the nose gear collapsed, resulting in heavy damage to the aircraft.
The investigation
The investigation focused on the engine's performance degradation and the pilot's decision-making process. Although the pilot suspected a faulty spark plug, no mechanical anomalies were found in the engine or its accessories following the accident. Investigators also examined the possibility of carburetor icing, noting that the pilot had not considered this cause because he believed icing only occurred when visible frost was present on the wings. The investigation also reviewed the pilot's flight preparation, noting that he had only reviewed ATIS information during his initial departure from Beauvais.
Findings
- The primary cause of the accident was the pilot's failure to detect a continuous loss of altitude while focused on monitoring airspeed.
- The pilot's flight preparation was insufficient for the changing weather conditions.
- An incorrect diagnostic was made regarding the engine issue, as the pilot misidentified the cause of the power loss.
- The pilot demonstrated persistence in continuing the flight despite the engine'related performance issues.