What happened
On October 18, 2022, a Cessna 172S, registration JA80AP, operated by Asahi Airlines Co., Ltd., was conducting continuous touch-and-go training at Yao Airport. The flight involved an instructor and a trainee working toward a commercial pilot certificate. The training session was designed to practice crosswind landings and power-off approaches.
During the final planned landing of the session, the aircraft approached the runway with an unstable path angle. As the aircraft passed the runway threshold, the Precision Approach Path Indicator (PAPI) showed four red lights, signaling a dangerously low approach. Despite the unstable condition, the approach continued. During the flare, the aircraft entered a floating state. When the instructor eventually initiated a go-around, the aircraft's sink rate increased rapidly, causing the underside of the aft fuselage and the rudder to strike the runway surface.
The impact caused the aircraft's tie-down ring to fracture and detach, which was later found on the runway. The aircraft also sustained skin abrasions on the rudder and aft fuselage. No injuries were reported for the crew.
The investigation
The Japan Transport Safety Board (JTSB) examined the flight history, meteorological data, and the aircraft's physical condition. Investigators analyzed the training procedures, specifically the "Assist" protocol where an instructor provides manual corrections to a trainee. The investigation also reviewed the company's Standard Training Procedures (STP) regarding go-around criteria and crosswind limits.
Investigators found that the aircraft was flying with a residual crab angle and was positioned approximately 8 meters to the left of the runway centerline at the time of contact. The investigation also noted that while the aircraft's integrated flight deck had the capability to record flight data, no data was recorded for this specific incident.
Findings
- The primary cause of the incident was the failure to execute a go-around once the aircraft met established safety criteria, specifically when it entered a floating state.
- A significant contributing factor was the instructor's decision to continue the approach to allow the trainee to experience a landing, despite the unstable flight path.
- The "Assist" procedure was found to be ambiguous; the lack of clear callouts meant the trainee relied on the instructor's inputs, effectively shifting the primary control responsibility without formal communication.
- The rapid increase in sink rate during the go-around was likely due to a stall-like condition caused by high pitch and reduced airspeed during the transition from floating to climbing.