What happened
On the afternoon of January 9, 1999, a Robin DR 315 aircraft, registration F-BRFH, was conducting a solo flight near Cucq, France. The flight was being operated by a flying club. During the approach phase, while flying at an altitude between 800 and 1000 feet, the pilot experienced engine vibrations. In response, the pilot activated the carburetor heat for several seconds while requesting priority from the Le Touquet tower to proceed to runway 32.
However, the engine instability intensified, resulting in a loss of power that was insufficient to maintain level flight. Faced with the deteriorating engine performance, the pilot elected to perform an emergency landing in a field located before the runway threshold. Upon touchdown, the saturated ground caused the nose gear to collapse, forcing the aircraft into a sudden upward pitch. This movement caused the leading edge of the right wing to strike the ground before the aircraft settled on its main landing gear, resulting in substantial damage to the airframe.
The investigation
The investigation focused on the engine's performance and the environmental conditions at the time of the accident. Meteorological data indicated a temperature of 4°C with a dew point of 3°C, accompanied by light rain showers. Following the accident, the engine, a Lycoming O-235, was examined for mechanical failures. Investigators found blackened spark plugs, which are indicative of an excessively rich fuel mixture, a condition often associated with carburetor icing. No other mechanical anomalies were identified in the engine during the inspection.