Phoebus C accident during turbulent approach at Montricher airfield
On June 29, 1971, a Bölkow Phoebus C glider encountered difficulties during its final approach to Montricher Airfield in Switzerland. The pilot, having released from tow near Orbe, aimed to glide to Montricher but faced strong turbulence and downdrafts. During the approach to runway 03, the glider stalled and crashed, coming to rest inverted in a field. The pilot sustained serious injuries, and the glider was significantly damaged. The official investigation confirmed that the accident resulted from a loss of speed in turbulent crosswind conditions.
- Aerotow cross-country: The pilot was aerotowed from Neuchâtel and released near Orbe at about 1700 m MSL to glide toward Montricher airfield.
- Turbulent crosswind joran: At Montricher a W–NW joran wind of 10–15 knots produced moderate turbulence and downdrafts near the terrain, creating challenging approach conditions.
- Low, close downwind: During the left-hand downwind for runway 03, the pilot ended up too low and too close to the runway axis, likely underestimating the strength of the crosswind.
- Strong turbulence encountered: While flying the left-hand downwind leg for runway 03, the glider encountered strong turbulence and downdrafts that caused a rapid loss of altitude.
- Circuit shortened: As altitude decreased quickly, the pilot shortened the landing circuit and initiated a final 180° turn about 150 m before the runway threshold.
- Stall in final turn: In the turbulent air during the 180° turn toward runway 03, the glider’s airspeed became insufficient, it stalled on the left wing, and the pilot lost control.
- Crash - serious injury: The glider descended to the ground and came to rest inverted in a field near Montricher at 19:15, seriously injuring the pilot and causing severe damage to the aircraft.