What happened
On July 15, 2007, a Robin DR 315 aircraft, registered F-BPRC, was conducting a local flight departing from Châlons Ecury-sur-Coole. During the cruise phase of the flight, the pilot observed significant fluctuations in engine RPM, with the engine speed varying between 1,400 and 1,8 to 1,800 RPM.
In an attempt to reach the nearby Épernay aerodrome, the pilot made several adjustments to the power controls. However, unable to maintain level flight, the pilot decided to perform an emergency landing in a nearby field. Although the engine performance briefly appeared to improve during the final approach, a subsequent drop in power forced the pilot to land in a recently harvested field on a downward slope. Following the touchdown, the aircraft traveled approximately 200 meters before the nose gear collapsed, resulting in damage to the forward section of the aircraft. There were no fatalities among the two occupants.
The investigation
The investigation focused on the mechanical failure of the engine and the maintenance practices of the aero club. Technical examination of the engine revealed a leak in the mechanical fuel pump. Investigators also reviewed the club's internal reporting procedures and maintenance logs.
It was discovered that a club member had experienced a similar power loss while flying the same aircraft the previous day. This pilot had noted the anomaly on a piece of paper kept with the aircraft logbook and in a club notebook. However, the club's mechanic was never informed of this issue. Furthermore, a club official conducting a check flight on the day of the accident did not detect any irregularities and dismissed the previous day's report as a simple misuse of the carburetor heat system.
Findings
- The primary cause of the engine instability was a leak in the mechanical fuel pump.
- During the power fluctuations, the pilot did not activate the electric fuel pump to compensate.
- A significant breakdown in safety culture existed within the aero club, characterized by a lack of attention to technical anomalies.
- The club's management had discouraged members from recording incidents in the official aircraft logbook, instead using an unofficial notebook that was rarely consulted by pilots or mechanics.
- There was no evidence of repairs being performed for any of the eleven technical observations recorded in the club notebook since October 2006.