What happened
On March 21, 2015, a Schleicher ASK13 glider, registration D-5620, was performing a local flight at the Épinal Dogneville aerodrome. The flight began at 15:35 when the glider was towed into the air. Approximately five minutes later, the glider was released at an altitude of roughly 700 meters, about four kilometers north of the airfield. At the time of release, the pilot estimated the wind to be 20 km/h from 290 degrees.
After failing to find sufficient thermal lift, the pilot decided to return to the airfield at approximately 15:50. The pilot entered a left-hand traffic pattern for runway 02 at the optimal approach speed. During the base leg of the pattern, the pilot realized the aircraft was low on the glide path. Believing that the wind effects had not been sufficiently compensated for, the pilot deployed the air brakes. During the final approach, the glider struck treetops approximately 400 meters before the offset runway threshold. The aircraft came to a stop in the trees, and the pilot was able to evacuate the aircraft without assistance.
The investigation
The investigation utilized a flight recorder installed in the glider to establish the precise flight path. Data from the recorder showed that the pilot began searching for lift at 15:42 at an altitude of about 700 meters. Meteorological data from the Épinal Dogneville station indicated a wind of 350 degrees at approximately 32 km/h at the time of the accident. However, the recorder indicated that during the traffic pattern, the wind was actually between 340 and 350 degrees at 20 km/h.
Investigators also reviewed the pilot's flying experience. The pilot, a flight instructor with various licenses, had a total of approximately 190 flight hours. However, the pilot had not flown a glider since October 2014, having only completed 50 minutes of flight time in the preceding three months during a supervised check flight.
Findings
- The pilot's insufficient recent experience on this specific aircraft type.
- An inadequate assessment of the glide path due to failing to properly account for the effects of the wind during the approach.