Collision du SZD-55-1 avec un avion stationné à l'aérodrome de Bad Ragaz lors d'un lancement par remorquage

Le 30 mars 1992, un PZL Bielsko SZD-55-1 a été impliqué dans un incident lors d'un lancement par remorquage à l'aérodrome de Bad Ragaz en Suisse. Peu après le début du remorquage, l'aile droite du planeur a touché le sol, le faisant dévier de la piste pavée. Le pilote a largué le câble de remorquage mais n'a pas pu arrêter le planeur, qui est entré en collision avec un avion Mooney stationné. Le planeur a subi des dommages mineurs, tandis que le Mooney a été gravement endommagé. Le pilote a subi des blessures légères. L'enquête a identifié une installation incorrecte du contrôle des ailerons comme un facteur contributif.

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 total ground roll of about 100 meters, the unbraked glider collided heavily with a parked Mooney M20J, causing major damage to the Mooney, minor damage to the glider, and minor injury to the pilot.