Accident Summary
On July 14, 2024, at approximately 11:31 Japan Standard Time, an Alexander Schleicher ASK13 glider (registration JA2469) operated by a corporation was involved in an accident during a solo flight training session at the Kitami District Temporary Operation Site in Kitami City, Hokkaido Prefecture. The glider, a two-seater, was occupied solely by a 21-year-old trainee pilot. After performing a landing approach to Runway 10, the glider touched down at the target point but bounced, floated about 1 meter, and then made a hard landing. The trainee pilot sustained a fractured spine and was transported to a hospital.
Flight History
The glider took off from the 800 m x 25 m paved runway strip (Runway 10) at 11:14 via aero tow for solo flight training required for a private pilot license. After releasing the tow rope at about 2,100 ft altitude, the glider passed a checkpoint on the south traffic pattern at approximately 1,400 ft and began its approach to Runway 10. At about 11:31, as the glider flew at an airspeed of approximately 100 km/h and touched down at the touchdown target point (about 150 m from the runway threshold), it bounced, floated, and then hit the ground hard. The glider rolled to a stop about 310 m from the threshold. The trainee pilot could not exit unaided due to lower back pain but was assisted by the flight instructor and other trainees. An ambulance took the pilot to the hospital, where a fractured spine was diagnosed.
Pilot and Training Details
The trainee pilot held a valid flight training certificate and had accumulated 31 hours 51 minutes of flight time (83 launches), with 20 hours 48 minutes on the same glider type. On the day of the accident, the trainee had completed two onboard training sessions with a flight instructor and received a proficiency certificate for solo flight based on safety criteria from the Japan Civil Aviation Bureau. The accident flight was the trainee's fourth solo session. The flight instructor, aged 32, held a private pilot certificate (glider) and a flight instructor rating, with 388 hours 41 minutes total flight time (1,579 launches). According to statements, during the onboard training earlier that day, the instructor noted that the trainee's approach speed was sometimes 95 to 100 km/h instead of the recommended 90 to 95 km/h. The instructor felt the trainee's skills had generally improved and approved solo flight. Witnesses at the command post observed the glider touch down on the runway centerline but noted the approach angle appeared large and the flare operation insufficient.
Analysis and Probable Cause
The Japan Transport Safety Board analyzed that when the glider bounced and floated at touchdown, the proper recovery maneuver would have been to close the dive brakes and hold the stick until the glider began to sink, then flare again. However, the trainee pilot likely kept the nose up, causing the angle of attack to increase gradually, leading to a hard landing from about 1 meter height. The board found it highly probable that the bounce resulted from the glider approaching without proper speed control, combined with insufficient flare and inadequate sink rate management. The trainee pilot's inexperience and unstable skills, due to training conditions, were considered contributing factors. The probable cause was stated as: when the glider bounced and floated at the time of the touchdown, the trainee pilot most likely kept the nose of the glider up without performing the recovery maneuver, causing the angle of attack to gradually increase and the glider to make a hard landing from a height of about 1 meter, resulting in the injury to the trainee pilot.