Pilatus B4-Absturz während Trainingsflug in der Nähe von Ulrichen, Schweiz
Am 29. Juli 1987 war ein Pilatus B4-PC11AF in einen Absturz nahe Ulrichen, Schweiz, während eines Trainingsflugs verwickelt. Der Pilot, der im Rahmen eines alpinen Segelfluglagers solo flog, klinkte das Schleppseil in einer unzureichenden Höhe von 2100 Metern aus. Trotz der Erkennung des Fehlers setzte der Pilot den Flug fort, um eine Rückkehr nach Münster aufgrund von Zeitplanbeschränkungen zu vermeiden. Das Segelflugzeug geriet in einem Kurvenflug in einen Strömungsabriss und kollidierte mit einem steilen Hang. Der Pilot erlitt schwere Verletzungen, und das Flugzeug wurde zerstört.
- Aerotow to ridge: During an alpine gliding camp, the pilot departed Münster in aerotow in a Pilatus B4 for a solo training flight along the Goms valley.
- Premature tow release: After a 180° turn near the Oberwaldergrimsel/Chietal area, the pilot released from tow at about 2100 m MSL, already below local ridge height contrary to prior instruction.
- Desire to avoid landing: Realizing she had released too low, the pilot nevertheless decided to continue the flight to avoid an early landing at Münster that would prevent another launch due to reservations.
- Low, slow ridge flying: In pure thermal conditions and with shallow local slopes, the pilot flew slow figure‑eight patterns close to the hillside, reducing height margin for corrections.
- Poor speed monitoring: The pilot flew mainly by feel and paid little attention to the airspeed indicator while maneuvering near the slope.
- Stall and loss of control: During a turn toward the valley at low height, the glider dropped below minimum flying speed, stopped responding properly to control inputs, and departed controlled flight.
- Crash - serious injury: The glider impacted a steep slope near Flieli, 1.5 km northwest of Ulrichen, seriously injuring the pilot and destroying the aircraft.