Flight History
On Sunday, June 2, 1985, at 1500 local time, a pilot accompanied by his 17-year-old daughter departed from Sitterdorf airfield in a Piper J3C aircraft, registration HB-OCK, for a private flight. The weather was characterized by a bise wind condition. Approximately 30 minutes later, the pilot landed on a field owned by his brother near Mosnang, Switzerland, approaching from the southeast.
Accident Circumstances
At 1720 local time, the pilot and his daughter began the return flight. The takeoff was conducted in the opposite direction of the landing. After rolling approximately 200 meters, with the first 70–80 meters in the lee of a forest, the aircraft lifted off where the terrain began to slope downward. Without gaining altitude, the aircraft drifted increasingly to the right toward a small wooded area. The pilot was unable to avoid the obstacle, and the aircraft struck trees at an estimated height of 10 meters above the ground. The right wing was torn off, and the aircraft fell nose-first onto the forest floor.
Findings
- The pilot held a valid private pilot license but did not have permission for off-airport landings.
- The aircraft (Piper J3C with Rolls-Royce O-200-A engine and McCauley metal propeller) was certified for flight. No pre-existing technical defects were found, and weight and balance were within limits.
- Weather in the region was dominated by a high-pressure system with a moderate, dry bise wind. At the accident site, the sky was lightly clouded with a base around 2000 meters, visibility over 20 kilometers, wind from the north-northeast at 3–10 knots with gusts up to 20 knots, temperature 22°C, dew point 8°C, and pressure 1018 mbar.
- The field used for takeoff was dry with short grass.
Cause
The official investigation determined the cause as a misjudgment of wind influence before takeoff.
Injuries and Damage
The pilot's daughter, who occupied the front seat, suffered severe head injuries. The aircraft was destroyed.