Introduction
On 6 August 1964, a Piper Cub J3C, registration HB-OEM, operated by Fliegerschule Birrfeld, was involved in an accident at Montreux airfield in Switzerland. The aircraft was performing a landing as part of a supervised 300 km cross-country flight. The accident resulted in no personal injuries but caused significant damage to the aircraft.
Aircraft and Pilot
The aircraft, a Piper Cub J3C, had a maximum weight of approximately 480 kg and held a valid airworthiness certificate issued on 30 March 1963, valid until 29 May 1965. The brakes were found to be in working order both before departure from Birrfeld and after the accident.
The pilot, born in 1926, held a student pilot license issued on 14 January 1963, valid until 8 January 1965, with an extension for cross-country flights granted on 10 June 1964. His total flight experience was 36 hours with 185 landings.
Accident Sequence
The student pilot departed from Birrfeld for the first leg of his cross-country flight, which was supervised by his flight instructor. He arrived at Montreux as planned and initiated a landing on runway 01 at 12:15. The landing direction was consistent with the landing-T indicator and the windsock, indicating a moderate north wind.
During a normal approach, the pilot experienced a gust of wind shortly before touchdown, which lifted the aircraft to about 3 meters. He added power and continued the landing. The aircraft touched down on its main landing gear in the first third of the 700-meter grass runway, but the tailwheel did not contact the ground. The aircraft, having little forward speed, began to pitch forward: instead of the tail settling, it gradually rose until the aircraft stood vertically on the propeller hub. It remained in this unstable equilibrium for a few moments before tipping completely onto its back.
Damage
The aircraft sustained the following damage: the wooden propeller was broken; the engine cowling was dented; the top edge of the rudder was dented; the right wing was damaged, with the upper strut attachment point dented and the wing twisted. Estimated repair costs were 3000 to 4000 Swiss francs, representing about 20% of the aircraft's value.
Investigation Findings
The investigation considered the possibility of a sudden wind change at touchdown, but noted that such a change would need to persist for some time to cause a nose-over. It was deemed more likely that the brakes were applied during or shortly after touchdown. The student pilot stated that he had no reason or intention to brake but did not rule out the possibility of inadvertent application.