What happened
On April 29, 2016, a Centrair 101 glider, registration F-CHEF, departed from the Mont-Dauphin Saint-Crépin airfield via winch launch. After releasing the cable at an altitude of 370 meters, the pilot attempted to gain altitude in the eastern sector of the airfield. Unable to climb, the pilot decided to terminate the flight and began a left-hand circuit for runway 16.
During the final approach, the glider began to gain altitude, shifting the intended touchdown point toward the end of the runway. In an attempt to lose altitude, the pilot performed a 360-degree turn, which resulted in a loss of approximately 50 meters of height. Seeking to regain the desired descent profile, the pilot increased the descent rate and fully extended the airbrakes. However, as the aircraft reached short final, the pilot retracted the airbrakes to arrest the descent. This maneuver was performed just as the pilot began the flare, only two meters above the ground. Consequently, the aircraft struck the ground heavily while still in a nose-down attitude.
The investigation
The investigation examined the pilot's flight experience, the aircraft's performance, and the flight data recorded by the FLARM system. The pilot, who had approximately 400 total flight hours with 40 hours on this specific type, noted that he had limited recent experience with the Centrair 101. He observed that the aircraft's handling characteristics regarding speed stability differed from his previous experience with the LS4 model.
Flight data analysis revealed that the aircraft's average indicated airspeed during the airfield circuit was approximately 130 km/h. This speed increased during the final approach, exceeding 150 km/h following the 360-degree turn. This was significantly higher than the manual's recommended approach speed of 90 km/h (or 102 km/h considering the day's wind conditions).
Findings
- The primary cause of the accident was inappropriate approach management, characterized by excessive airspeed from the start of the approach, which prevented a stabilized trajectory during short final.
- The pilot's decision to retract the airbrakes prior to the flare prevented the necessary reduction in speed.
- The pilot likely focused too heavily on the touchdown point, leading to a late flare.
- The pilot's limited recent experience with this specific glider type may have contributed to the error.