What happened
On March 30, 1970, a Piper J3C, registration HB-OXR, was engaged in a ferry flight from Bad Ragaz to Buttwil. During the approach to the Buttwil airfield, the pilot observed that the runway conditions were poor due to recent snowmelt, which had rendered the southern half of the grass strip unusable. Consequently, the pilot decided to land on the northern half of the runway, approaching from a direction contrary to the standard traffic pattern.
As the aircraft approached the landing zone, the pilot realized the aircraft had drifted too far to the left of the runway centerline. The aircraft initially touched down on the left side of the northern strip. In an attempt to recover, the pilot applied full power and initiated a go-around. During this maneuver, the pilot entered a left turn toward descending terrain, which led to a loss of airspeed and a subsequent wing stall. The aircraft slid across the ground, resulting in heavy damage to the airframe.
The investigation
The investigation examined the pilot's experience, the aircraft's weight and balance, and the environmental conditions at the time of the accident. It was noted that the pilot was operating under a student pilot certificate and was performing a ferry flight authorized by an instructor. The investigation also reviewed the aircraft's loading, finding that the Piper J3C was overweight at both the initial departure and during the accident.
Findings
- The primary cause of the accident was a failed go-around following an improper approach.
- The pilot's decision to land on the northern half of the runway, deviating from the standard pattern, contributed to the error.
- The pilot's flight experience was insufficient to manage the complexities of the non-standard approach and the subsequent recovery attempt.
- The pilot's visibility was further obstructed because they were seated in the rear seat, with a passenger in the front seat.
- The aircraft was operating above its maximum allowable takeoff weight, though this was not determined to be the decisive factor in the crash.
- The pilot failed to execute a go-around at the moment the lateral deviation from the runway centerline was first identified.