What happened
On May 15, 2012, a Robin DR 400–120, registration F-BXRB, was conducting a dual instruction flight at Chavenay-Villepreux aerodrome. Due to approaching thunderstorm conditions, the instructor opted to cancel a planned solo navigation flight in favor of local circuits. During the flight, the crew performed several circuits and low-altitude exercises.
During the final circuit, the aircraft was cleared to land on runway 28 with winds from 320° at 15 knots. As the aircraft reached the flare, the right wing lifted, causing the left wingtip to strike the ground. The aircraft subsequently overturned and came to rest on its left side near a hangar, approximately 100 meters from the runway axis. The student and instructor sustained slight injuries, and the aircraft was destroyed. Shortly after the impact, heavy hail was observed at the aerodrome.
The investigation
The investigation focused on the meteorological conditions and the decision-making process of the crew. Investigators reviewed weather forecasts from the Toussus-le-Noble station and local observations at Chavenay, which indicated deteriorating conditions, including convective clouds (TCU/CB) and gusty winds. The student pilot noted seeing a thunderstorm cloud approximately 5 km west of the aerodrome during the flight.
Technical examinations of the wreckage revealed no mechanical anomalies or failures that could have contributed to the accident.
Findings
- The primary cause of the accident was the insufficient consideration of the effects of a nearby cumulonimbus cloud.
- The decision to terminate the flight was made too late, as the crew continued training despite known unfavorable weather.
- While the instructor attempted to intervene when the student's corrective actions failed to stabilize the aircraft, the loss of control was already irreversible.