What happened
On July 19, 2008, a Schempp Hirth Janus A glider, registration F-CEPC, departed from Valence aerodrome for a local flight. The aircraft was being towed by a tug plane with a pilot and one passenger on board. Shortly after exiting the Valence control zone, the pilot attempted to contact the tug aircraft on the glider frequency but received no response. Suspecting a radio tuning error by the passenger, the pilot attempted to signal the tug pilot using rudder pedal movements, but these signals went unnoticed.
Believing it was too low to safely return to the aerodrome, the pilot proceeded to the planned release point. The release occurred as scheduled, and the tug aircraft departed for Valence. Shortly after the release, the glider struck the treetops on the western slope of a ridge at an altitude of approximately 1,300 meters. The impact caused the aircraft to slide through the trees until it reached the ground. The accident resulted in one fatality (the passenger) and one serious injury (the pilot).
The investigation
The investigation focused on the sequence of events following the release and the state of the aircraft's systems. Investigators examined photographs taken by the passenger during the flight, which provided critical evidence regarding the aircraft's electrical state. The wreckage was recovered the day after the accident in a wooded area near the ridge summit. The investigation also included testimonies from both the glider pilot and the tug aircraft pilot.
Findings
- The investigation established that the glider experienced an electrical power failure starting from the initial taxiing phase. This was evidenced by the fact that the FLARM device failed to record the flight and the electric variometer showed a zero reading, identical to its appearance when powered off.
- The electrical failure was limited to non-essential equipment and did not affect the primary flight controls.
- A breakdown in communication occurred because the glider pilot was unable to establish radio contact with the tug pilot and failed to successfully signal the issue via visual maneuvers.
- The exact cause of the impact could not be definitively determined due to the lack of direct witnesses and the pilot's loss of memory regarding the final moments of the flight.