What happened
On May 6, 1972, a training flight initiated from Olten airfield ended in an accident near Niederbipp. The pilot was operating a K 6 E glider, registration HB-853, under aero-tow. After approximately 90 minutes of flight in moderate thermals, the pilot encountered a cumulus cloud and decided to terminate the flight. During the return leg toward Olten, the aircraft encountered severe gusty downdrafts, which caused the altitude to drop to approximately 300 meters.
Due to the deteriorating conditions, the pilot opted for an outlanding on a mown meadow northeast of the village. While executing the approach on a heading of 130 degrees, the aircraft crossed railway power lines. The pilot deployed the air brakes and initiated a side-slip to manage the descent. However, the aircraft's landing distance was longer than anticipated, and it touched down only 20 meters before the end of the available field. In an attempt to maneuver between a strip of tall grass and a wooden utility pole, the right wing of the K 6 E struck the pole. The impact caused the aircraft to veer right, coming to rest in an adjacent field.
The investigation
The investigation examined the pilot's experience, the airworthiness of the aircraft, and the meteorological conditions at the time of the accident. The pilot held a valid license with passenger endorsements and possessed significant experience on the specific aircraft type. There was no evidence of medical impairment or prior incidents in the pilot's record. The HB-853 was found to be airworthy and properly maintained, with no pre-existing mechanical defects identified. Weather observations indicated visibility of 12 to 20 km and variable winds of 5 to 10 knots, which increased in strength near localized showers.
Findings
- The pilot encountered unfavorable wind conditions, specifically gusty downdrafts and a possible tailwind component, which extended the landing roll.
- The chosen landing site contained obstacles, including a utility pole, which the pilot failed to sufficiently account for during the final approach.
- The aircraft sustained heavy damage, though the pilot remained uninjured.