What happened
On August 13, 1967, a Piper J3C, registration HB-OSM, was performing a private flight from La Blécherette to La Côte. The pilot was attempting to complete the necessary flight time to renew a private pilot license before its upcoming expiration. During the landing sequence at La Côte airfield, the pilot performed a maneuver to observe the landing direction but failed to check the windsock.
Approaching runway 22 in turbulent conditions, the aircraft maintained a high and fast approach, resulting in a long touchdown. The aircraft initially contacted the ground with the main gear, bounced, and briefly leveled off approximately one meter above the surface while maintaining a high pitch attitude. Upon a second contact with the runway, the aircraft suddenly entered a ground loop. There were no injuries to the pilot or the passenger, though the aircraft sustained significant damage.
The investigation
Investigators examined the aircraft's mechanical condition and the pilot's actions. The aircraft had recently undergone a 100-hour inspection, and subsequent checks confirmed that the brakes were fully functional, albeit with a progressive application. The investigation also reviewed the pilot's credentials, noting that while he held a special permit for training flights, he was flying with a passenger, which was not authorized under his specific permit terms. The aircraft's weight and balance were found to be within prescribed limits, and the slight overload present at the time of the accident was determined to have no influence on the event.
Findings
The investigation established that the ground loop was caused by the abrupt application of the brakes by the pilot. Following the long touchdown and the subsequent bounce, the pilot, fearing the aircraft would run out of runway, applied the brakes forcefully. This action, combined with the aircraft's high pitch attitude and the pilot's potential tension, triggered the overturn. The pilot failed to realize that approximately 220 meters of runway and an additional 150 meters of usable terrain remained available for a controlled stop.