Atterrissage dur de l'ASK 21 pendant l'entraînement à l'aérodrome de Schänis
Le 11 octobre 1990, un élève-pilote volant un Alexander Schleicher ASK 21 à l'aérodrome de Schänis en Suisse a subi un atterrissage dur. C'était le troisième vol solo du pilote dans le planeur. Lors de l'approche, le planeur était trop haut et hors trajectoire, ce qui a conduit à une série de corrections de trajectoire. L'instructeur a conseillé au pilote de redresser, mais la manœuvre a été exécutée trop brusquement, provoquant une montée puis une descente rapide du planeur. L'élève-pilote a subi des blessures graves, tandis que le planeur a été légèrement endommagé.
- Aerotow landing pattern: During the third solo flight after an aerotow in an ASK 21, the student entered the landing circuit for runway 34 with the CG 10 mm behind the aft limit.
- Aft CG beyond limit: The glider was flown with two trim weights missing, placing the centre of gravity 10 mm aft of the allowable rear limit, making pitch control more sensitive.
- High, offset final: The student flew a high base and final, turning into final too late and ending up about 120 m left of the runway 34 centreline.
- Aggressive course corrections: On final at about 120 km/h, the student first corrected slightly right, then made strong right and left corrections to regain the runway centreline, remaining high and under stress.
- Nose-down then over-pull: Shortly before the threshold the student pushed the nose down, increasing speed, then after the instructor’s radio call to 'pull' she pulled back too strongly on the stick.
- Balloon then sink: The glider ballooned to about 7 m above ground and then sank through in a nearly level attitude with half airbrakes extended and the nose slightly down.
- Crash - serious injury: The glider impacted near the right edge of the paved runway, causing serious injury to the student pilot and minor damage to the aircraft.