Le SZD-55 percute un avion stationné après une prise d'aile au remorquage

Lors d'un décollage remorqué à Bad Ragaz, un SZD-55-1 a posé une aile, a quitté la piste et a percuté un Mooney stationné ; pilote légèrement blessé, planeur légèrement endommagé, Mooney fortement. Au septième vol du pilote sur le type, peu après la tension du câble, le bout d'aile droit a touché l'herbe ; un levier d'aileron mal monté en usine avait réduit l'efficacité au roulis, si bien que le manche à fond n'a pu relever l'aile et le planeur est sorti. Le pilote a largué tard sans freiner ; le planeur a roulé ~100 m contre le Mooney. Causes : touche d'aile et sortie de piste, largage tardif, aileron affaibli, frein non utilisé.

1. Aerotow takeoff roll: During an aerotow departure on runway 12, the SZD-55-1 began its takeoff roll in variable 5–10 kt wind for the pilot’s seventh conversion flight on type.
2. Misrigged aileron control: The right aileron drive lever had been incorrectly installed at the factory, giving both ailerons excessive positive setting and reducing roll control effectiveness.
3. Right wing contacts ground: Shortly after the towplane began to pull, the glider’s right wingtip touched the ground in the grass area beside the paved runway.
4. Veer off runway: The right wing was decelerated by the low grass and, despite full opposite aileron, the glider yawed and departed the hard-surface runway after about 30 meters.
5. Tow cable released late: After being unable to raise the wing, the pilot released the nose hook tow cable only after roughly 50 meters of ground run, by which time the glider was already off the runway.
6. Wheel brake not used: With only about three seconds remaining before impact, the pilot did not apply the wheel brake and the glider continued rolling unchecked toward a hangar.
7. Crash - minor injury: After a ground roll of about 100 meters, the unbraked glider collided heavily with a parked Mooney M20J, causing major damage to the Mooney, minor glider damage, and minor pilot injury.