What happened
On February 17, 1974, a private flight involving a Stinson 10-8-2 "Voyager", registration HB-TUR, was conducting a flight from La Côte to Sion. The aircraft was carrying the pilot and three passengers. During the final approach to Sion Airport's runway 08, the pilot received information regarding a 15-knot wind. To extend the approach trajectory, the pilot applied additional power as the aircraft crossed the runway threshold with flaps extended.
Upon touchdown, the aircraft initially made a three-point landing but subsequently bounced slightly. During this maneuver, the right wing lifted, causing the nose to yaw to the left. Although the pilot attempted corrective actions, the aircraft could not be fully stabilized. The plane settled on its left wheel and began a ground loop to the right. During the excursion, the left wingtip struck the ground and the left landing gear collapsed under the fuselage. The aircraft came to a stop approximately 450 meters from the runway threshold, 7 meters right of the centerline. All four occupants were unharmed and evacuated the wreckage independently.
The investigation
The investigation examined the pilot's credentials, the aircraft's maintenance status, and the environmental conditions at the time of the accident. The pilot held a valid private pilot license and showed no signs of impairment. While the pilot had significant experience in tricycle gear aircraft, his experience with tailwheel aircraft was more limited, specifically regarding landings on paved surfaces; he had performed only two landings on paved runways in the Stinson 108-2.
The aircraft was found to be in a valid state of airworthiness, with the weight and center of gravity within prescribed limits. Technical inspections revealed no mechanical deficiencies. Weather conditions at the time were sunny with visibility exceeding 10 km and a 15-knot wind from the east-northeast.
Findings
- The primary cause of the accident was the inadequate use of flight controls or brakes during the landing phase.
- The pilot's limited experience with tailwheel landings on paved runways contributed to the loss of control.
- There was a potential failure to adequately compensate for wind conditions during the landing maneuver.