Incident Overview
On 23 May 1965, a Piper Cub J3C, registration HB-OUO, was involved in an accident on a military airfield. The aircraft was being used for a forced landing exercise, under the instruction of a flight instructor.
Sequence of Events
During the exercise, the flight instructor intended to apply power. However, the engine did not respond immediately, probably because it had become too cold. As the instructor attempted to turn the aircraft into line with the runway axis, the airplane stalled from a low altitude, tipping over the right wing.
Damage and Injuries
The aircraft sustained substantial damage, estimated at approximately 15 percent of its value. The occupants were uninjured.
Investigation Findings
The investigation concluded that the engine's delayed response was likely due to cooling. No other causal factors were identified.