Incident du Grunau Baby à l'aérodrome de Birrfeld : collision avec une berge lors de l'atterrissage
Le 11 avril 1967, un Edmund Schneider Grunau Baby II a subi un incident d'atterrissage à l'aérodrome de Birrfeld, en Suisse. Le pilote a tenté d'atterrir après un court vol mais a mal jugé l'altitude. L'aile gauche du planeur a heurté une berge de 2,5 mètres de haut, provoquant une rotation de 180 degrés de l'appareil et des dommages importants au contact du sol. Le pilote a subi une blessure par compression d'une vertèbre lombaire. L'enquête a souligné l'inexpérience du pilote et la difficulté à estimer l'altitude comme facteurs contributifs.
- Aerotow local flight: The pilot aerotowed from Birrfeld to the Holderbank/Schinznach-Bad area for a local soaring flight of about 10 minutes.
- Altimeter malfunction: Shortly after takeoff the pilot noticed the altimeter was not indicating correctly, forcing him to estimate his altitude for the remainder of the flight.
- Low experience and recency: The pilot had only about 21 hours total gliding experience, roughly 3 hours since his license, and had not flown for more than three months prior to this flight.
- Misjudged height for circuit: On returning to Birrfeld, the pilot incorrectly assessed that his height was sufficient to fly a half circuit and integrate into the landing pattern for runway 26 instead of planning an immediate outlanding.
- Flies low base-to-final: He flew the downwind leg along the 600 m runway and then, about 100 m east of it, initiated a 180° left turn toward final approach at an insufficient height above ground.
- Left wing strikes earth bank: During the low-altitude left turn, the glider’s left wingtip struck a 2.5 m high earth bank located along the extension of the southern runway boundary, causing the aircraft to yaw almost 180° and touch down in a strong sideslip.
- Crash - minor injury: The glider landed hard outside the airfield boundary, sustaining substantial damage, and the pilot suffered a lumbar vertebral compression injury.