What happened
On June 22, 2024, a JONKER JS-MD 3 RES glider, registration D-KPWZ, was returning to the La Motte-du-Caire aerodrome following a local flight. The pilot, estimating a north-northwest surface wind of 30 km/h, initiated a landing pattern for a north-facing approach. During the transition to the base leg, the aircraft's airspeed increased from 120 km/h to 155 km/h, and the glider gained approximately 30 meters in altitude.
Recognizing that the aircraft was too high and too fast, the pilot fully extended the airbrakes and flaps. While flying over the runway, the pilot attempted a 180-degree turn to land on the reciprocal runway but subsequently abandoned this maneuver to execute an emergency procedure. This procedure involved using a parking area at the end of the runway as a clearway. However, as the pilot attempted to land in a field beyond the parking area, the glider struck vegetation and collided with the ground.
The investigation
The investigation, supported by data from the aircraft's FLARM flight computer, established that the actual meteorological conditions differed from the pilot's assessment. While the pilot anticipated a strong Mistral wind, the actual surface wind was a light to moderate northerly valley breeze with gusts up to 37 km/h, and no significant turbulence or curl-overs were present.
Investigators examined the pilot's flight path and the aircraft's configuration. The data showed an average descent slope of 17% during the approach, consistent with the use of full airbrakes. The investigation also reviewed the pilot's experience and the specific landing instructions provided by the La Motte-du-Caire flying club, which require non-standard approach patterns due to the local terrain.
Findings
Several factors contributed to the non-stabilized approach and subsequent collision:
- An incorrect assessment of the wind conditions, which led the pilot to fly a deliberately high approach to avoid perceived turbulence.
- An unexpected gain in altitude at the start of the base leg, potentially caused by pilot control inputs or localized downdrafts.
- A lack of a prepared strategy to manage the approach once the aircraft became unstable.
- The pilot's concentration on reducing excess airspeed, which may have led to a failure to monitor the descent slope effectively.