K-8B Zwischenfall am Flughafen Grenchen während des zweiten Alleinfluges eines Flugschülers

Am 26. Juni 1978 ereignete sich ein tödlicher Unfall mit einem Flugschüler, der ein Alexander Schleicher K-8B Segelflugzeug flog, kurz nach dem Start vom Flughafen Grenchen. Während des Schleppstarts begann das Segelflugzeug zu schwingen und löste sich schließlich in einer Höhe von etwa 100 Metern vom Schleppflugzeug. Das Segelflugzeug ging in einen steilen Steigflug über, gefolgt von einem Strömungsabriss, und stürzte senkrecht ab, was zur Zerstörung des Flugzeugs und dem Tod des Piloten führte. Die Untersuchung konnte die genaue Ursache des Kontrollverlustes nicht ermitteln.

1. Aerotow takeoff: On his second solo flight in the K-8, the student pilot began an aerotow takeoff from runway 25 in strong, gusty crosswind and turbulent conditions.
2. Tow oscillations develop: Shortly after liftoff, the glider began increasingly pronounced wave-like pitch oscillations behind the towplane during the initial climb.
3. Challenging wind and turbulence: The flight took place in strong, gusty winds with significant turbulence, conditions under which the student had already shown difficulty on the previous landing.
4. Low experience on type: The student pilot had limited solo experience overall and had completed only one prior flight on the K-8 that day, during which he had control difficulties in the crosswind landing.
5. High tow position and release: While in a steep climb attitude and about 10 meters above the towplane, the student released the tow rope from the glider.
6. Steep turn and stall: Immediately after release, the glider entered a very steep, nose-high right turn, then transitioned into an almost vertical, apparently uncontrolled dive from about 100 meters above ground.
7. Crash - fatal: The glider impacted the ground at high speed near the end of the airfield, destroying the aircraft and killing the student pilot on impact.