What happened
On the afternoon of May 28, 1970, a student pilot was conducting solo training flights at Grenchen Airport. After completing several dual-control flights and two successful solo flights earlier that morning, the pilot attempted a fourth solo flight at 17:32 local time.
During the takeoff roll, the Piper J3/C began to drift slightly to the right. In an attempt to stabilize the aircraft, the pilot applied heavy left rudder correction. This maneuver caused the aircraft to lift off prematurely while in a left-wing-low attitude. The aircraft drifted 45 degrees to the left, crossing the edge of the runway. As the left wingtip struck the ground, the aircraft's momentum caused it to skid, eventually resulting in the propeller striking the earth and the aircraft coming to rest upside down.
The investigation
Investigators examined the flight sequence and interviewed the flight instructor, who was present on the runway during the incident. The investigation focused on the pilot's control inputs and the physical conditions of the runway. The aircraft, registration HB-OFV, was a Piper J3C powered by a Continental A65 engine. The investigation noted that the runway in use was 530 meters long and 30 meters wide, featuring some surface irregularities.
Findings
- The primary cause of the accident was an inappropriate rudder correction used to counteract the initial rightward drift.
- The pilot's aggressive left-foot input led to an unintended lift-off in an unstable flight attitude.
- The pilot's lack of experience contributed to the accident, as they failed to take corrective action to maintain a normal flight attitude once the aircraft left the runway surface.
- Surface irregularities on the runway may have contributed to the aircraft's unexpected lift-off during the correction attempt.
There were no injuries to the pilot, and the aircraft sustained damage estimated at approximately 40 percent of its value.