History of the Flight
On December 20, 2015, a Piper PA-18-150, registration JA4048, operated by the General Incorporated Association Shizuoka Prefecture Aeronautical Association, was conducting a glider towing flight at Fujikawa Gliding Field. After towing a glider and releasing it northwest of the field, the aircraft flew south over the sea at about 1,500 ft, then passed over the field at about 1,000 ft and turned northeast. The pilot observed the windsock, which was hanging limp. The aircraft then turned north and began a landing approach to runway 18.
During the final approach, the pilot noted a higher-than-normal approach path angle, attributing it to a tailwind. After lowering the flaps to the full position and dropping the towrope, the pilot entered the landing attitude but felt the aircraft yawing to the right. The pilot applied left wing-low and right rudder instinctively. The main wheels touched down on the right side of the runway centerline, beyond the halfway mark. The pilot pulled the control column fully aft to lower the tailwheel, but the aircraft veered right, departing the runway onto the grass. Despite rudder inputs, the aircraft continued toward a bush. The pilot then applied full brakes, causing the aircraft to nose over onto the bush.
Damage to Aircraft
The aircraft was substantially damaged. Observed damage included a bent main wing strut, wrinkles in the fabric of the bottom main wing, and a bent propeller.
Meteorological Information
The pilot reported the weather as roughly clear with a light wind from the north-northeast and visibility of 10 km. The windsock was hanging limp, indicating calm or very light wind conditions at the time of the accident.
Accident Site
The accident occurred on a bush area approximately 133 m north of the terminal end of runway 18 and about 15 m west of the runway edge. The bush was about 2 m high. Tire marks from the tailwheel were found on the grass, initially curving right and then proceeding almost straight.
Pilot Information
The captain, a 61-year-old male, held a Commercial Pilot Competence Certificate and a Class 1 Aviation Medical Certificate. His total flight time was 532 hours and 20 minutes, with 6 hours and 50 minutes on the accident aircraft type.
Aircraft Information
The aircraft was a Piper PA-18-150, serial number 3076, manufactured on January 31, 1989. It had a total flight time of 3,214 hours and 40 minutes at the time of the accident.
Additional Information
The operating association had standard procedures for towing flights. The pilot had prepared a document titled "The Points of Towing by Aircraft" based on these procedures. The procedures specified approach speeds, altitudes, and landing roll techniques. During taxiing, direction control is mainly by braking on the main wheels, while during landing and takeoff rolls, control is via rudder and a linked tailwheel.
Analysis
The Japan Transport Safety Board analyzed the weather conditions and found it highly probable that weather was not a factor, given the calm winds. The aircraft's damage occurred when it rolled forward and overturned after the pilot applied strong braking to avoid the bush. The pilot's actions during the approach and landing, including the application of left wing-low and right rudder, were noted as probable factors in the aircraft's yaw and subsequent veer-off.