What happened
On March 12, 2022, a Beechcraft A3 36, registration JA4577, was conducting a familiarization flight at Iejima Airport in Okinawa, Japan. The flight was operated by a non-profit organization (NPO) for the purpose of evaluating a potential new captain. The aircraft was occupied by the captain and a passenger acting as a supervisor.
During the approach to Runway 04, the aircraft descended below the intended flight path. The aircraft struck the airport's perimeter fence and the sloping terrain located short of the runway. The impact caused the aircraft to bounce and crash into a grassy area, where it was destroyed by a subsequent intense fire. The impact resulted in two fatal injuries for the occupants.
The investigation
The Japan Transport Safety Board (JTSB) examined radar track records, witness statements, and the wreckage of the aircraft. Investigators noted that the aircraft was not equipped with a flight data recorder, which limited the ability to reconstruct the exact sequence of control inputs.
Physical evidence at the site showed that the aircraft's wings had struck the fence posts, and the nose landing gear had detached upon impact with the slope. The investigation also reviewed the pilot's recent history, noting that while the captain was a highly experienced pilot, he had not operated an aircraft for approximately seven years and was on only his second flight with this specific aircraft type. Furthermore, the investigation looked into the NPO's training and management protocols for pilots using aircraft for which they lacked recent type-specific experience.
Findings
Several factors contributed to the aircraft's failure to maintain a safe approach path:
- An optical illusion likely caused by the uphill gradient of Runway 04, which can lead pilots to believe they are at a higher altitude than they actually are.
- The pilot's lack of familiarity with the Beechcraft A36 maneuvers and unstable engine power control.
- A potential failure to execute a timely or sufficiently powered go-around after the descent was detected.
Additionally, the JTSB found that the NPO lacked documented training records and a formal system to manage the competency of pilots performing familiarization flights.
Safety action
Following the accident, the NPO implemented new protocols for pilot training. These include entrusting initial and recurrent training to individuals with specific experience in the aircraft type, ensuring all training is managed by designated staff, and maintaining formal records of all training activities.