Process and Progress of the Accident Investigation
On September 22, 2022, at about 13:57 JST, a Cessna 172P, registration JA3969, landed at Yao Airport and contacted an equipment storage box attached to the pole of an apron floodlighting while taxiing toward Spot H4. The left wing leading edge was damaged. The aircraft was privately owned and had two persons on board; no one was injured.
The Japan Transport Safety Board (JTSB) designated an investigator-in-charge and an investigator on October 14, 2022. An accredited representative from the United States, as the State of Design and Manufacture, participated.
Factual Information
Aircraft: Cessna 172P, serial number 17276563, manufactured February 12, 1986. Airworthiness certificate valid until April 27, 2023, in the normal category.
Personnel: The captain, aged 40, held a commercial pilot certificate and a Class 1 aviation medical certificate, with 379 hours total flight time (114 hours on type). The fellow pilot, aged 73, held a private pilot certificate and a Class 2 medical certificate, with 1,781 total flight hours (1,760 on type). Both had no flight time in the 30 days prior.
Meteorological conditions at 14:00: Wind 060° at 14 kt, visibility 10 km or more, temperature 27°C, dew point 20°C.
The flight departed Kumamoto Airport at 11:11, about an hour behind schedule, with the captain supervising the fellow pilot's instrument flight training. The fellow pilot landed on Runway 09 at 13:54 and taxied toward Spot H4. While taxiing on taxiway P1, the fellow pilot felt pressured about the reserved spot use time and radioed the controller for an extension. Seeing a "G" marking, the fellow pilot thought they might have passed the entrance to the Lead-in Lines for Spot H but continued, then saw an "F" marking and recognized they had passed the entrance. The fellow pilot then turned right at the entrance to the Lead-in Lines for Spot F to avoid stopping, entered the GSE Service Road, and the left wing contacted the equipment storage box.
Damage: A dent about 60 cm long, 16 cm wide, and 6 cm deep on the left wing leading edge, with upward bending of the outer skin on the upper surface. The equipment storage box had coating peeling.
The day before, the fellow pilot had checked the apron plan view but did not note the GSE Service Road, which is not for aircraft. While taxiing, the fellow pilot did not notice the change from yellow guide lines to white lines. The captain had also seen the plan view but did not recognize the GSE Service Road during taxi. The captain relied on the fellow pilot's familiarity with the airport and did not monitor the route.
Analysis
The JTSB concluded that the fellow pilot probably passed the entrance to the Lead-in Lines for Spot H due to pressure from the looming spot use time and while radioing the controller. The captain left it up to the fellow pilot and did not notice the missed entrance. After passing, the fellow pilot, concerned about other aircraft, turned right instead of stopping. The fellow pilot likely thought the GSE Service Road was passable and did not confirm with the captain or controllers. The captain was occupied with a radio response and did not look out when entering the road.