What happened
On August 18, 2018, a Schleicher ASK13 glider, registration F-CECY, was performing a winch launch training exercise at Chambéry Challes-les-Eaux. The flight was part of an instructional session involving a student pilot and an instructor. The objective of the maneuver was to simulate a cable break at a very low altitude.
During the climb, the instructor released the winch cable at an altitude of approximately eight meters. Following the release, the student pilot immediately lowered the nose and deployed the airbrakes. Due to the extremely low altitude, the instructor was unable to prevent the aircraft from making a hard impact with the unpaved runway. The accident resulted in one serious injury to the student pilot and significant damage to the glider.
The investigation
The BEA analyzed video footage of the takeoff, which confirmed the low altitude of the maneuver and the student pilot's deployment of the airbrakes. The investigation also reviewed the backgrounds of the crew members. The instructor, a club employee with 643 flight hours, had recently completed instructor training at the CNVV, where winch-launch cable break simulations were not practiced. The student pilot, with 22 total flight hours, had previously performed similar exercises at much higher altitudes (above 100 meters).
Interviews revealed that the instructor decided to release the cable earlier than expected to save time for subsequent solo flight preparations, without notifying the student. The student pilot, expecting a release between 20 and 25 meters, was surprised by the sudden release at only eight meters, which prompted the immediate deployment of the airbrakes.
Findings
- The primary cause of the accident was the premature deployment of airbrakes by the student pilot before reaching the minimum appropriate approach speed.
- The instructor performed the cable release at an altitude significantly lower than recommended safety standards.
- The instructor's training at the CNVV had not included practice for winch-launch cable break simulations.
- The extreme low altitude of the maneuver left insufficient time for the instructor to intervene or correct the flight path once the airbrakes were extended.