What happened
On August 6, 1987, a student pilot accompanied by an instructor departed from Grenchen in a Piper PA-38-112 (HB-PGI) for a training flight in Ticino. After landing at Locarno and later Lugano, the pair proceeded to Ascona. Following a touch-and-go, the instructor disembarked after the second landing and instructed the student to perform three solo circuit patterns.
The takeoff occurred at 15:43 local time. During the first approach, the instructor noted via radio that the aircraft was slightly high. The student corrected the glide path by reducing power but crossed the runway threshold at a good height yet excessive speed. Anticipating a long landing roll, the student applied full throttle at approximately one meter above the ground to initiate a go-around.
Immediately upon increasing power, the Piper PA-38 yawed sharply to the left toward two parked aircraft. The instructor radioed an instruction to apply right rudder. The student complied, causing the aircraft to turn right in a highly nose-up attitude. The plane then rolled over its right wing and pitched forward, striking the hard-surface runway from a height of 5 to 6 meters. It skidded diagonally across the runway before coming to rest upright on the opposite side. The pilot, wearing shoulder harnesses, exited the heavily damaged aircraft uninjured.
The investigation
The SUST examined the flight history, weather conditions, and mechanical status of the HB-PGI. The student held a valid learner permit with roughly 35 hours total time, including recent solo experience. The aircraft was airworthy with flaps fully extended and weight within limits. Weather was VFR with weak, variable winds and good visibility.
The investigation focused on the pilot's actions during the go-around. It was determined that the decision to go around was correct given the approach parameters. However, the sudden application of full power without adequate rudder correction caused an uncontrolled yaw. The subsequent corrective action involved pulling back on the elevator while applying rudder, which likely kept the nose high.
Findings
The accident was caused by improper control input during the initiation of a go-around. Specifically:
- The pilot failed to counteract the torque effect of increased power with sufficient left rudder initially, causing a dangerous left yaw.
- Upon correcting the yaw with right rudder, the pilot likely maintained excessive back pressure on the elevator, leading to an aerodynamic stall and loss of control.
- Fatigue was identified as a contributing factor. The student had flown extensively that day, including multiple circuits and previous landings, which may have impaired reaction times and judgment.
Safety action
The SUST highlighted the importance of managing power changes during go-arounds, particularly in high-performance or torque-sensitive aircraft like the Piper PA-38. Emphasis was placed on coordinated control inputs to prevent yaw-induced stalls during critical low-altitude phases of flight.