On September 24, 1969, an AG FÜR DORNIER-FLUGZEUGE BÜ 131 (registration HB-USL) was involved in an aviation accident near Speck-Fehraltorf Flugplatz (LSZK), ZH, CH. Investigators recorded the probable cause as: The aircraft veered off the runway edge into a field, leading to a sudden deceleration and a subsequent rollover. This summary draws on records from the Swiss Transportation Safety Investigation Board (STSB / SUST).
A Bücker Jungmann aircraft overturned after veering off the runway into a beet field during a landing attempt in September 1969.
What happened
On September 24, 1969, a Bücker Jungmann, registration HB-USL, was attempting to land at the Speck-Fehraltdorf airfield. As the sun was setting, the pilot initiated the landing approach approximately 5.3 meters outside of the runway perimeter. During the landing roll, the aircraft drifted off the paved surface and entered a beet field. The impact with the terrain caused a sudden deceleration, which resulted in the aircraft flipping over.
The investigation
The investigation focused on the flight path during the final approach and the subsequent excursion from the runway. Investigators established that the aircraft's departure from the runway was the immediate precursor to the rollover event. The investigation confirmed that despite the significant force of the deceleration and the aircraft's inversion, there were no injuries to the occupants.
Findings
The aircraft drifted approximately 5.3 meters beyond the runway edge during the landing phase.
The primary cause of the accident was the aircraft's excursion into a beet field, which provided enough resistance to trigger a rollover.
The aircraft sustained substantial damage as a result of the accident.
Probable cause
The aircraft veered off the runway edge into a field, leading to a sudden deceleration and a subsequent rollover.