What happened
On July 23, 2012, a Schleicher ASH 25 M glider departed from the Füssen glider airfield for a local sightseeing flight. The pilot intended to introduce a passenger, a new club member, to the local alpine environment.
Following takeoff, witnesses observed the aircraft performing turns near the Kienberg mountain, approximately 12 km west of the airfield. The aircraft was flying at an altitude of less than 100 m above the ridge with varying degrees of bank angle. A witness observed the glider enter a steep dive into the forest. The wreckage was located on the southern slope of the Kienberg at approximately 1,200 m AMSL. Both occupants were killed in the accident.
The investigation
The BFU examined the wreckage, which had sustained extreme structural damage, including a shattered cockpit and broken wings. No technical defects were found in the aircraft, though the takeoff mass was slightly above the maximum allowable limit. The investigation also reviewed the pilot's medical history and flight experience.
While the pilot held a valid license and significant flight experience, post-mortem findings revealed severe coronary artery disease. The investigation noted that the pilot's medical condition, specifically the presence of significant arterial narrowing and the use of blood-thinning medication, might have been grounds for disqualification had it been known during his medical examinations. Although no acute medical event could be proven during the flight, the condition could not be ruled out.
Findings
- The primary cause of the accident was an aerodynamic stall resulting from flying at an excessive attitude with insufficient airspeed during a turn.
- The low altitude prevented the pilot from recovering from the resulting spin.
- Challenging wind conditions, characterized by moderate to strong turbulence and gusts exceeding 20 knots, contributed to the difficulty of the flight.
- The pilot's infrequent flight practice was a contributing factor.