Flight Sequence
On the morning of 23 June 2002, the pilot arrived at Bex airfield with three passengers for a flight over the Alps. After preparation and refuelling, the pilot noted that the takeoff weight limit was likely reached. The aircraft departed from runway 15 at approximately 09:20 local time and left the circuit via downwind towards Lake Geneva. The flight path was reconstructed from witness statements and the surviving passenger's account. The aircraft flew along the right bank of the lake to Blonay, crossed the lake towards Le Bouveret, then ascended the valley past the Chavallon power plant above Vouvry. Several witnesses observed the aircraft flying very low with frequent roll oscillations and alternating engine power. The surviving passenger stated that the pilot wanted to demonstrate the aircraft's capabilities. The pilot briefly gave controls to the front passenger, who felt uneasy. Over the lake near Blonay, he briefly activated the magnetos to show that the aircraft could fly without engine power. Near Le Bouveret, he made a low-altitude turn over a naturist camp. Intending to fly over Lake Tanay, the pilot turned west into the valley towards Col de Verne. While entering the valley, the aircraft was below the elevation of Miex. The pilot, holding the radio button, was heard at Bex airfield informing passengers they were overflying Miex. A witness in Miex observed the pilot, south of the village, extend the climb with a loop before continuing north towards the ridge near Prélagine. Reaching the ridge, he attempted a left turn towards Lake Tanay but apparently realised altitude was insufficient. Then north of the ridge, he initiated a right turn and overflew the ridge again from the north. Despite losing altitude, the pilot continued the right turn. Slightly below the ridge, the aircraft struck trees on the steep slope and crashed onto the rocky ground. A witness heard the impact noise and alerted police at 09:43. Initial search efforts were unsuccessful due to the wreckage being hidden in the forest. A REGA helicopter crew later picked up the signal from the emergency locator transmitter of HB-PMD and located the wreckage. The impact site was saturated with fuel but no fire occurred. The two front occupants were dead. Another passenger was in critical condition and died shortly after rescue. The fourth occupant was seriously injured but conscious.
Investigation Findings
The pilot held a valid Private Pilot License (PPL(A) CH) issued by the Federal Office of Civil Aviation, with a total flight time of 270:19 hours, including 30:56 hours on type. His last medical examination was on 24 May 2002, with a Class 2 medical certificate valid until May 2004 without restrictions. The pilot had started flight training on 6 April 1985, first solo on 3 July 1987 after 24:36 hours, and obtained his PPL on 7 September 1989 with 84:07 hours. Up to the accident flight, he had logged 857 landings, 150:25 hours as pilot-in-command. Two flight instructors described the pilot as conscientious and conservative; his training level was considered low but sufficient for safety. The previous evening, the pilot attended a wedding with his wife, leaving at 02:00. He bought pastries between 08:15 and 08:30 before the flight, resulting in a potential rest period of about five hours. Autopsy revealed no health issues that could have affected the accident; toxicology was negative, and blood alcohol was zero. The deaths were due to injuries from the crash. A simple flight list with the names of the three passengers was prepared. All occupants had fastened seatbelts, which withstood the impact. Weather at the accident site was cloudless, visibility about 20 km, wind 230° at 3–6 kt, temperature 20°C, dew point 11°C, QNH 1021 hPa. The sun elevation was 34.74°, azimuth 91.39°. The aircraft was refuelled with 80.5 litres of AVGAS before departure; total fuel on board was 147 litres (231 lbs). The takeoff weight was 2617 lbs, exceeding the maximum of 2550 lbs by 67 lbs (2.6%). The centre of gravity was within the aft limits. Examination of the wreckage found no malfunctions or deficiencies that could have contributed to the accident. All switches were in expected positions; the ignition key was missing. The engine had separated from the fuselage; the propeller was deformed, indicating engine power at impact. Detailed component inspections found no anomalies. The aircraft had a valid airworthiness certificate; last 100-hour check on 26 February 2002, last 50-hour check on 3 May 2002. The engine had been overhauled and reinstalled on 26 February 2002, accumulating 78:42 hours since.
Cause
The collision with terrain was due to inappropriate flight tactics in mountain flying. Possible contributing factors were the pilot's low training level and lack of flight experience, as well as fatigue after a short night's rest.