Accident Overview
On 8 February 1987, at approximately 1635 local time, a Piper PA-32R-301T Lance, registered HB-PIW, struck the ground near the locality of Marmoud in La Sagne, canton Neuchâtel, Switzerland. The aircraft was destroyed and the pilot, a Swiss national born in 1941, sustained fatal injuries. The flight was a private cross-country from Avignon-Caumont, France, to La Chaux-de-Fonds, Switzerland.
Flight History
The pilot obtained a weather briefing via teleprinter for the route. He filed an international flight plan routing via Montélimar, La Tour-du-Pin, Chambéry, and Thonon. Departing Avignon at 1455, the pilot was the sole occupant. At 1506, he contacted Marseille Information, reporting flight level 75. He later switched to Geneva Information and then Geneva Terminal. Radar recordings show he followed the planned route until crossing Lake Geneva.
At 1521, the pilot requested descent to flight level 55 due to clouds at altitude, which was approved. At 1530, he contacted Les Eplatures airfield, inquiring about the cloud base; the operator reported 200 meters above ground. The pilot then stated he was in a dense fog area. Witnesses near La Sagne saw the aircraft emerge from clouds in a nose-low attitude with landing gear extended, flying north-south at very low altitude over the village, then re-enter clouds. They heard a turn within the clouds and then saw it exit in a steep dive, impacting a snow-covered field south of La Sagne.
Investigation Findings
The pilot held a valid private pilot license issued in 1975, with endorsements for radiotelephony and controlled visual flight (CVFR), and was authorized to fly aircraft with flaps, variable-pitch propeller, and retractable landing gear. Autopsy concluded death was solely due to impact trauma; no alcohol was detected. The aircraft had a valid airworthiness certificate and was maintained per regulations. Examination of the wreckage showed the landing gear was extended at impact; propeller deformation indicated high engine power. The destruction precluded further detailed examination.
The aircraft was equipped with an automatic landing gear extension system that deploys when speed drops below a certain threshold; the system could be locked. Investigation could not determine whether it was locked at impact.
Weather at La Chaux-de-Fonds (1200 and 1800 UTC) showed deteriorating conditions with low visibility and overcast clouds. At the accident time near La Sagne, wind was southwest 10 knots, visibility 2–5 km, light drizzle, overcast stratocumulus at 1200–1500 m above sea level, temperature 3°C, relative humidity 95%, and moderate turbulence near the ground.
Probable Cause
The accident was due to continuing visual flight into instrument meteorological conditions. Contributing was loss of orientation over snow-covered terrain.