Nimbus 2C collision with railway line during approach at Montricher, Switzerland

On May 12, 1990, a Schempp-Hirth Nimbus 2C was involved in a collision with a railway line during its approach to Montricher airfield in Switzerland. The pilot, returning from a training flight, encountered descending air currents and was unable to maintain sufficient altitude. Despite attempts to clear the obstacle, the glider struck the railway's overhead line, causing significant damage to both the aircraft and railway infrastructure. The pilot sustained minor injuries. The investigation confirmed the accident resulted from insufficient altitude to clear the obstacle.

1. Cross-country return: After a training cross-country flight from Montricher toward the Jura, the pilot turned back near La Chaux-de-Fonds due to deteriorating weather and flew toward Montricher with sufficient altitude to arrive but with little reserve.
2. Prolonged sink encountered: While following the eastern slopes of the Jura on the return leg, the glider flew through a large area of descending air, reducing altitude to about 1200 m AMSL near Romainmôtier, 7.5 km from the airfield.
3. Low height margin: At L'Isle, about 3 km from Montricher, the pilot judged he had just enough altitude to reach runway 21 directly but without any height reserve to follow a normal circuit and standard approach.
4. Continued direct low approach: Despite recognizing the minimal height margin and the presence of suitable fields below, the pilot elected to continue a straight-in, downwind approach to runway 21 instead of committing to an outlanding.
5. Attempt to clear railway: Approaching the Biére–Apples–Morges railway line and realizing he could not overfly it with his remaining height, the pilot dived to gain speed and then pulled up in an attempt to 'jump' over the overhead wires.
6. Impact with catenary: During the pull-up maneuver the glider’s left wing struck the railway catenary, causing the aircraft to pivot about a quarter turn to the left and lose control.
7. Crash - minor injury: The glider crashed onto the road alongside the railway, sustaining severe damage and causing major damage to the railway installations, while the pilot received only minor injuries.