Incident Ka-2b lors d'un remorquage à l'aérodrome de Spreitenbach entraîne un atterrissage dur

Le 1er juin 1963, un Alexander Schleicher Ka-2b a rencontré des difficultés lors d'un lancement en remorquage depuis l'aérodrome de Spreitenbach en Suisse. Le planeur a subi des déviations d'altitude importantes, l'empêchant de maintenir un remorquage stable avec l'avion remorqueur De Havilland Chipmunk. Le pilote a largué le remorquage à environ 30 mètres d'altitude et a effectué un atterrissage dur sur un champ ouvert, endommageant le fuselage. Le pilote a subi des blessures légères, tandis que le passager est resté indemne. L'enquête n'a révélé aucun défaut technique dans le planeur.

1. Aerotow initial climb: The Ka-2b glider with a passenger began a normal aerotow takeoff and initial climb behind a Chipmunk tug from Spreitenbach airfield with nose-heavy trim set.
2. Uncontrolled height deviations: Shortly after liftoff at about 10 m AGL the glider began to make strong altitude deviations relative to the tug, including pronounced over- and under-height positions that the pilot could not stabilize with elevator inputs.
3. Low tow energy: The glider’s large height excursions in turbulent conditions caused excessive drag and energy loss, preventing the tow combination from gaining normal speed and climb performance.
4. Tow release at low height: Recognizing the situation as critical and believing there might be an elevator fault, the glider pilot released from tow at about 30 m AGL during a right turn in front of Dietikon.
5. Insufficient speed and height: After release the pilot rolled wings level and aimed for a nearby field but did not have enough altitude and airspeed to establish a proper glide, leading to an increasingly steep, stalled descent.
6. Crash - minor injury: The glider struck the field hard in an over‑stalled attitude beside a power line, damaging the fuselage and control system and causing minor back injuries to the pilot while the passenger remained unhurt.