What happened
On May 31, 2003, at approximately 12:35 local time, an A. Schleicher ASH 26E motor glider, registration HB-2262, was performing a winch-assisted takeoff at Samedan Airport, Switzerland. The aircraft was being operated as part of a private training camp.
After a short takeoff roll of roughly 50 meters, the aircraft lifted off at a shallow angle. Witnesses observed that at an altitude between 10 and 20 meters, the left wing dipped slightly, followed by a sudden drop of the right wing. This caused the aircraft to roll rapidly into an inverted position. The glider struck the edge of the paved runway in an inverted state, slid approximately 70 meters along the surface, and came to rest at the edge of the runway. The pilot sustained fatal injuries at the scene.
The investigation
Investigators examined the aircraft's configuration and the environmental conditions at the time of the accident. The A. Schleicher ASH 26E was found to be correctly assembled, with the engine retracted and the flaps set to position 3. The aircraft's weight and balance were within prescribed limits, and the fuel levels were within operational parameters.
Meteorological data from the Samedan weather station revealed a significant shift in wind conditions. Shortly before the accident, the wind direction had changed by approximately 180 degrees, shifting from a headwind to a light tailwind, accompanied by increased gusts. The investigation also reviewed the pilot's recent flight history, noting that while experienced in mountain soaring, the pilot had performed relatively few winch launches in the preceding years.
Findings
- The primary cause of the accident was a loss of control during the winch launch, leading to a collision with the terrain.
- A sudden change in wind direction from a headwind to a tailwind, combined with gusts, likely contributed to the instability.
- The aircraft experienced a stall, which triggered the rapid roll and subsequent inversion.
- The pilot's recent experience with winch-assisted takeoffs was limited.
- An unexpected medical episode or malaise involving the pilot may have played a role in the loss of control.
Safety action
- The Federal Office of Civil Aviation (FOCA) should review whether periodic medical fitness assessments for glider pilots, similar to those required for powered aircraft pilots, should be reintroduced.