What happened
On May 4, 2019, a privately owned Piper PA-4SB-350P, registered JA121C, was conducting a VFR leisure flight from Yao Airport to Oshima Airport. Upon arrival, the pilot encountered low clouds that obscured the runway from view at lower altitudes. Although the active runway was Runway 03, the pilot elected to land on Runway 21, despite being informed by the Information Officer that a tailwind of approximately 7 knots was present.
During the approach, the pilot initiated an early base turn, which resulted in a shorter final leg and a flight path closer to the runway than usual. This maneuver left the pilot with insufficient time to complete standard landing configurations; the landing gear was not extended until the aircraft was already lined up with the runway, and the flaps were only set to 20° instead of the full 36°. Additionally, the aircraft's approach speed was approximately 110 KIAS, significantly higher than the 80 to 85 KIAS recommended in the flight manual.
The aircraft touched down beyond the halfway marking of Runway 21. While the pilot initially applied normal braking to avoid tire bursts, the aircraft could not be stopped within the remaining runway length. After applying maximum braking near the threshold of Runway 03, the aircraft overran the pavement and came to a halt on uneven ground, sustaining damage to the nose gear, propellers, and wing leading edge.
The investigation
The Japan Transport Safety Board (JTSB) examined the flight history, weather conditions, and aircraft performance data. Investigators reviewed communications between the pilot and the Information Officer, as well as statements from airport administration staff who witnessed the landing. The investigation focused on the aircraft's approach stability, the impact of the tailwind on braking distance, and the pilot's decision-making regarding the landing runway and configuration.