Flight
On Saturday, 27 May 1972, at 1400 local time, the pilot of a Piper J3C, registration HB-ODW, departed from Bern-Belp airport to take part in a formation flight with two other aircraft during a public aviation event. Due to very strong wind, the pilots of all three aircraft terminated the demonstration early. The pilot of HB-ODW left the formation first and landed on grass runway 32 in strong gusty crosswind. After the landing roll, while turning left, the aircraft was hit by a strong gust and overturned onto its back at 1407.
Damage
The pilot remained uninjured. The aircraft sustained heavy damage. No third-party damage occurred.
Findings
The pilot, born in 1910, held a valid limited professional pilot license and a flight instructor license. Total flight experience was 1990 hours, with 645 hours on the accident type. During the previous 90 days, he flew 7 hours, including 1 hour and 32 minutes on type. No evidence indicated any health impairment at the time of the accident. No prior accidents or incidents were recorded in the Federal Air Office files.
The aircraft was airworthy and certified for operation. Investigation revealed no pre-existing defects.
Weather in the accident area, as provided by the Swiss Meteorological Center, was: 3/8 stratocumulus at 1200 meters above the airfield, visibility 20–30 km, surface wind 280° at 15 knots, gusting to 30 knots.
Assessment
During the accident flight, the pilot occupied the front seat. The center of gravity of the loaded aircraft was therefore in the forward part of the permissible range, which favored overturning by the strong wind.
Cause
The accident was caused by the pilot's insufficient consideration of the wind influence.