What happened
On September 2, 1961, a Norécrin II aircraft, registration HB-DUA, departed from Kägiswil airfield for a specialized photography mission. The flight's purpose was to capture images of mountaineers climbing the North Face of the Eiger. The crew consisted of the pilot and two passengers, including a photojournalist.
After performing several maneuvers around the Eiger peak and flying along the North Face in a descent, the aircraft entered a climb near the West Ridge. At an altitude of approximately 3,500 meters, the aircraft suddenly dropped a wing during the climb, entered a spin, and struck the E/Eiger Glacier roughly 350 meters below. The impact destroyed the aircraft and resulted in three fatalities.
The investigation
The investigation examined the flight profile, the pilot's experience, and the aircraft's technical condition. The aircraft, a single-engine, four-seat low-wing monoplane, was found to be in good technical condition with no mechanical failures identified. The investigation also reviewed the pilot's training, noting that while he was a reliable pilot, he had only undergone a brief 10-minute transition training on this specific model and lacked aerobatic experience.
Findings
Several contributing factors were identified during the investigation:
- The pilot failed to maintain sufficient altitude and airspeed margins while maneuvering in complex terrain.
- The aircraft's tendency to stall and wing-drop abruptly at low speeds was a critical factor.
- The pilot's lack of specific experience with the stall characteristics of the Norécrin II made recovering from the wing-drop difficult.
- The presence of an unbuckled passenger likely caused a significant distraction or physical obstruction to the pilot during the emergency.
- The high altitude and reduced air density contributed to a rapid loss of altitude following the initial wing-drop.
- The complex terrain and lack of a clear horizon made spatial disorientation more likely.