Background
The pilot and two passengers were forced to spend the night at Schwarzsee (Lac-Noir) after experiencing engine troubles. The following day, they decided to depart for Thun Aerodrome, located approximately 26 kilometers northeast of their position.
Accident
Shortly after takeoff, during the initial climb, the airplane stalled and crashed in a near-vertical attitude in a field about 500 meters northeast of the lake.
Casualties
One passenger was seriously injured in the crash, while both the pilot and the other passenger were killed. A few hours later, the seriously injured passenger died from his injuries, bringing the total number of fatalities to three.