What happened
On May 27, 1972, a Piper J3C, registration HB-ODW, was participating in a formation flight as part of a public aviation event at Bern-Belp Airport. Due to the presence of extremely strong winds, the flight formation was forced to abort the demonstration prematurely.
As the pilot attempted to land on grass runway 32, the aircraft encountered significant crosswind gusts. After completing the landing roll, the pilot in the front seat attempted to turn the aircraft to the left. During this maneuver, a powerful gust of wind struck the aircraft, causing it to flip onto its back at approximately 14:07 local time. The pilot escaped the incident without injury, though the aircraft sustained heavy damage. No third-party property was affected.
The investigation
The investigation examined the pilot's credentials, the aircraft's airworthiness, and the prevailing meteorological conditions. The pilot held valid commercial and flight instructor licenses, with a total of 1,990 flight hours, including 645 hours on this specific aircraft type. There was no evidence of health issues or prior incidents in the pilot's record.
Technical inspections confirmed that the Piper J3C was airworthy and properly registered, with no pre-existing mechanical defects found. Meteorological data indicated visibility of 1,200 meters and winds of 20–30 km/h, with gusts reaching up to 30 knots.
Findings
Investigators determined that the aircraft's center of gravity was positioned toward the forward limit of the allowable range because the pilot was seated in the front seat. This weight distribution made the aircraft more susceptible to overturning when hit by strong winds. The primary cause of the accident was the pilot's failure to sufficiently account for the impact of the wind conditions during the landing and taxiing phase.