What aircraft was involved and where did it happen?

The accident on 1968-04-16 involved a BEECH AIRCRAFT CORPORATION B35, registration HB-ECM, at Bellerive, VD, CH.

What was the probable cause of the accident?

The aircraft ran out of fuel during the flight, leading to engine power loss and a subsequent stall during a low-altitude turn.

Fatal engine failure leads to lake crash near Bellerive

A Beech Bonanza 35 crashed into Lake Geneva after running out of fuel during a low-altitude maneuver, resulting in four fatalities.

What happened

On April 16, 1968, a Beech Bonanza 35, registration HB-ECM, was performing a flight from Sion to Geneva. The aircraft, carrying the pilot and three passengers, was flying along the Savoie coast. At approximately 18:05 local time, while flying near the Anières-Chevrens road, the aircraft's landing gear was extended, and the pilot passed extremely close to the ground.

As the aircraft continued to follow the shoreline toward the southwest, the engine began to sputter near the Port of Corsier. Shortly after passing the Pointe de Bellerive, the pilot attempted a left turn. During this maneuver, the aircraft lost airspeed and plunged into Lake Geneva from an altitude of approximately 50 meters. All four occupants were killed, and the aircraft was destroyed upon impact.

The investigation

The investigation examined the aircraft's maintenance history, the pilot's flight records, and the fuel consumption requirements. The Beech Bonante 35 had been regularly maintained, and its engine had completed 720 hours of flight since its last overhaul. Investigators also reviewed the pilot's flight plan filed in Sion, which had estimated a flight duration of 20 minutes but failed to specify the aircraft's remaining endurance.

Physical examination of the wreckage revealed that the engine had been torn from the airframe, indicating a heavy frontal impact with the water. While the fuel selector was in the correct position, investigators noted a near-total absence of fuel on the water's surface at the crash site. The investigation also noted that the pilot's last refueling had occurred in Ajaccio on April 15, and no further refueling had taken place in Geneva.

Findings

The primary cause of the accident was a loss of airspeed resulting from fuel exhaustion.
The aircraft had been in flight for approximately 4 hours and 16 minutes since its last refueling, exceeding the available fuel supply.
The engine sputtering observed near Corsier was consistent with intermittent fuel starvation.
The fatal loss of lift occurred during a turn at a very low altitude, which left the pilot with insufficient margin to execute an emergency landing on the nearby available terrain.