Accident Overview
On 24 January 1965, a Piper L4 aircraft registered as HB-OXL was conducting a photographic flight in the Alps near Ollon, Switzerland. The aircraft crashed into a snow-covered slope at Roc d'Orsay, resulting in serious injuries to both occupants and substantial damage to the aircraft.
Flight History
The pilot and a photographer departed from Rennaz airfield at 1059 hours with the intention of taking aerial photographs over the Vaud Alps. After photographing the Leysin area, they flew to the Chamossaire region to capture the upper station of the Villars-Roc d'Orsay cable car.
The aircraft made two passes from east to west, using a right slip to descend to about 30 meters above the restaurant. After each pass, it climbed and turned over Combe d'Orsay. During a third pass from west to east, the pilot approached at reduced speed with engine at idle while maintaining a right slip. Expecting to hear the camera shutter, the pilot prolonged the slip until the restaurant was 100 meters ahead at his altitude. The passenger signaled readiness, and the pilot applied power, but fearing he might not clear the ridge and cable car wires, he turned sharply right to return over the combe. During the turn, the pilot felt the aircraft stall to the right. He pushed the stick forward to regain speed and descended into the combe, nearly parallel to the slope. As he came very close to the slope, he pulled up, but too late; the wheels struck the snow, and the aircraft sank vertically into the deep snowpack.
Investigation Findings
The investigation concluded that the accident was due to a loss of speed resulting from a prolonged slip. The pilot held a private pilot license with extensions for aerobatics, towing, and private pilot instruction, and had accumulated 2,817 flight hours. The aircraft, a Piper J3 C (certified as Piper L4 for its type), had a total authorized weight of 580 kg and was 13 kg under that limit at the time of the accident. Center of gravity was within limits.
Damage and Injuries
The aircraft was destroyed to 90% of its value. The pilot sustained a fracture of the right maxilla, a cut on the right cheek, and a contusion to the left knee, requiring one month of hospitalization and 7-8 weeks of incapacitation. The passenger suffered contusions and multiple cuts to the face. No third-party injuries or ground damage occurred.
Weather and Site
Weather conditions were calm with 2/8 cloud cover, visibility over 50 km, light north wind at 5 knots, and no turbulence. The accident site was at 1,940 meters elevation on a 45-degree slope with about 1.5 meters of snow.