What happened
On July 3, 1972, a training flight involving a student pilot and an instructor was underway at the Montricher airfield. The flight began with a towed takeoff from runway 21 using a Rhönlerche II glider, registration HB-592. After being released at approximately 300 meters altitude, the student pilot performed two right-hand spirals.
Following the maneuvers, the student pilot attempted an approach to runway 03, despite the fact that runway 21 was the active runway due to moderate to strong southwesterly winds. Noticing the student's intention to land on the incorrect runway, the instructor took control of the aircraft to redirect it toward the circuit for runway 21. During this transition, the glider's altitude dropped to roughly 120 meters as it flew through a shortened base turn against a headwind. As the aircraft approached the final segment, the instructor initiated a dive to clear a 4-to-5-meter tall hedge located approximately 175 meters from the runway threshold. However, the glider failed to clear the obstacle, striking a branch with its left wing before being brought to a halt by bushes near the hedge.
The investigation
The investigation examined the flight profiles, the experience of the crew, and the mechanical state of the aircraft. The student pilot had 23 total flight hours, including 13.15 hours on the specific glider type. The instructor was highly experienced, with over 390 flight hours and extensive training in various disciplines.
Technical inspections of HB-592 revealed no mechanical defects contributing to the event, though the total weight was noted to be 6 kg above the maximum authorized limit of 400 kg. Meteorological conditions at the time included southwesterly winds of 10-20 knots, visibility of 10-15 km, and localized showers and turbulence.
Findings
- The student pilot's error regarding the active runway caused a loss of time and altitude.
- The approach altitude was insufficient due to the student's initial mistake and the subsequent shortened circuit.
- The instructor's late intervention and the decision to perform a dive to clear the obstacle were contributing factors.
Safety action
- The investigation concluded that the accident could have been avoided had the instructor intervened earlier in the approach sequence.