Accident Overview
On 9 March 1961, a Pilatus Porter PC-6 (registration HB-FAR) operated by Aérodrome régional de Montreux S.A. was involved in an accident on the Plateau du Breithorn, Switzerland. The aircraft had transported six skiers from Montreux-Rennaz to the glacier earlier that day. After the skiers disembarked, the pilot attempted a solo takeoff at approximately 1025 hours (HEC) with an empty aircraft.
Pilot and Aircraft Information
The pilot, born in 1923, held a private pilot license (issued 15 July 1953) with a flight instructor extension (28 February 1961) and a restricted professional pilot license (issued 25 June 1958). He had a special authorization for commercial glacier flights since 5 October 1960. He had 552 flight hours and 2,685 landings, including 362 glacier landings (none on the Plateau du Breithorn). On the Pilatus Porter PC-6, he had 75 hours and 274 landings (98 on glaciers). The aircraft was a single-engine, high-wing, eight-place utility plane (serial number 340) with a Lycoming GS0-480-B1A6 engine (340 hp) and a Hartzell three-blade propeller. It was equipped with skis at the time of the accident. The aircraft's maximum takeoff weight was 1,800 kg; at the accident, it weighed approximately 1,400 kg. The center of gravity was within limits. The aircraft had accumulated 114 flight hours and 385 landings.
Accident Sequence
The pilot had never landed on the Plateau du Breithorn before. After arriving and landing at 1012 hours, he chose a northward takeoff direction on a slightly sloping snow surface approximately 200 meters long, with small snowdrifts. There was a strong tailwind (estimated 15-20 knots from 160°, gusting to 35 knots near terrain). At 1018 hours, the pilot applied full power. After covering about 200 meters, he began to ease back on the controls; the aircraft briefly became airborne over a small depression, then lost altitude and struck the ground hard with the right ski. This caused the right landing gear leg to break. The aircraft then continued in a climb. In flight, the pilot noted abnormal control feel. He decided to make an emergency landing at Sion airfield and received radio clearance. He performed a power-on approach and switched off the ignition just before touchdown at 1052 hours. The aircraft landed on the left ski (the ski retraction system was inoperative) and then tipped to the right, striking the right wing and landing hard on the tail.
Damage and Injuries
The aircraft sustained substantial damage: the landing gear, fuselage (from the ski impact during flight), tail section, right wing, and propeller were all damaged. The pilot was uninjured.
Investigation Conclusions
The investigation determined that the aircraft's contact with uneven terrain after takeoff was likely due to insufficient runway length for the required takeoff speed, given the tailwind and snow surface conditions. The pilot misjudged the favorable effect of the slope and underestimated the combined effects of tailwind and surface quality. The flap setting at takeoff could not be confirmed (15° or 30°; manual recommends 30° for optimum performance). The pilot's actions after the accident were considered prudent.
Reporting and Context
The aircraft had departed Rennaz earlier with six passengers; the takeoff weight exceeded the maximum by about 100 kg, but this was not considered related to the accident. The pilot held the necessary certifications for glacier operations.