What happened
On September 11, 2014, a Mudry Cap 10C, registration F-GNDL, was performing aerobatic instruction near the Dijon-Darois aerodrome. The flight, conducted by the Aéroclub de la côte d’Or, involved an instructor and a student pilot. During the maneuvers, the aircraft entered a spin. Witnesses observed the aircraft performing several rotations before it disappeared from view and subsequently crashed into a wooded area approximately one kilometer from the airfield.
The aircraft struck the vegetation with high energy while in a descent. The impact resulted in the death of the instructor and injuries to the student pilot. The aircraft was destroyed.
The investigation
The BEA examined the wreckage and the flight environment. Technical inspections of the F-G/GNDL revealed no mechanical anomalies; the flaps were retracted, the canopy was locked, and the transponder was in standby mode. The aircraft's weight and center of gravity were within manufacturer limits.
Investigators analyzed the dynamics of the spin. Witnesses described the spin as stable and "flat" (a shallow pitch attitude). The investigation also noted that on Cap 10 aircraft, the control stick is offset, which can lead a pilot to unintentionally apply aileron input when attempting to center the stick.
Furthermore, the investigation reviewed the instructor's training and the club's practices. While the instructor was highly experienced, the club had not practiced stabilized or flat spins since 2010 due to the perceived risks of the maneuver. The investigation also noted that the student had limited experience with the specific recovery procedures for flat spins in this aircraft type.
Findings
- The aircraft entered a flat spin, a highly dynamic and disorienting maneuver.
- The recovery was likely delayed because the instructor was using a recovery technique (nose-down input) optimized for standard spins rather than the specific procedure required for a flat spin (full aileron input).
- The available altitude was insufficient to complete a recovery once the flat spin had stabilized.
- The offset control stick design in the Mudry Cap 10C may have caused unintended aileron input during the maneuver.