What happened
On September 17, 2023, a privately owned Cessna 172P, registration JA4059, was performing a familiarization flight at Bibai City Farm Road Airfield in Hokkaido, Japan. The flight, which included the pilot in command and three passengers, was traveling from Sapporo Airfield to Bibai Airfield. During the final approach to Runway 20, the aircraft entered an unstable state.
An eyewitness observed the aircraft descending in a staircase-like pattern before making a hard touchdown and bouncing. The impact was significant enough that the aft lower fuselage made contact with the runway surface. While the pilot and passengers escaped without injury, the aircraft sustained damage, including scratches to the fuselage skin, damage to the rudder trim tab, and the breakage of the tail tie-on ring, which was later found on the runway.
The investigation
The Japan Transport Safety Board (JTSB) examined flight data from an aviation GPS device and interviewed witnesses to reconstruct the approach. The investigation compared the flight parameters of the incident to subsequent touch-and-go training maneuvers performed by the same pilot on the same day.
Investigators analyzed the aircraft's weight and balance, noting that the aircraft was carrying four occupants, which increased the gross weight to approximately 2,338 lb. The investigation also reviewed the pilot's recent flight history, noting that the pilot had returned to flying activities in August 2023 after an 11-year hiatus and had recently passed a competency assessment that suggested a need for improved proficiency in short-field landings.
Findings
Data from the GPS device revealed that the aircraft's ground speed during the incident was 10 to 15 knots lower than during the pilot's later training flights. This lower speed, combined with a headwind, placed the aircraft in a regime where the airspeed was likely below the minimums specified in the Flight Manual.
As the aircraft's speed decreased, it likely entered the "region of reversed command," where a higher power setting is required to maintain altitude. The investigation found that the pilot likely attempted to manage a high sink rate by increasing the nose-up attitude without adding sufficient power. This resulted in a high nose-up attitude at touchdown, causing the tail to strike the runway. The increased weight of the four-person occupancy further necessitated higher approach speeds to maintain stability and control.