What happened
On August 19, 1962, a Morane Rallye MS-880-B, registration HB-EDG, was conducting a private flight near the Dents Vertes region in Switzerland. The aircraft, operated by the Fribourg section of the Swiss Aero Club, departed from Ecuvillens carrying a pilot and two passengers.
During the flight, the pilot performed several low-altitude maneuvers near the Vounetse restaurant. Witnesses observed the aircraft flying at heights as low as 30 meters, performing turns around a nearby hill and waving its wings to greet tourists. During these maneuvers, the aircraft entered a tight turn and lost altitude. At approximately 11:40, the aircraft struck the awning of the restaurant before falling onto the ground. The impact destroyed the aircraft and caused three serious injuries to the occupants. A child present at the scene sustained minor injuries, and the restaurant building suffered light damage.
The investigation
The investigation examined the flight path, the pilot's experience, and the technical characteristics of the aircraft. While the pilot's account of the exact sequence of events differed slightly from witness testimonies, investigators focused on the flight conditions during the final maneuvers. The investigation also reviewed the operational characteristics of the aircraft's automatic leading-edge slats, which are designed to deploy at specific speeds to assist with low-speed flight.
Findings
- The aircraft was flying at an insufficient altitude and speed to recover from the maneuvers.
- The pilot performed high-risk, showy maneuvers at a very low height, significantly increasing the risk of an accident.
- It is highly probable that the aircraft experienced a stall or a sudden loss of lift during a turn.
- The deployment of the automatic leading-edge slats during a turn may have caused the aircraft to pitch down and tighten the turn, contributing to the loss of control.
- The pilot's recent transition to this specific aircraft type may have left him insufficiently aware of the specific handling characteristics of the automatic slats during maneuvers.