Accident Overview
On November 7, 2022, at approximately 09:49 JST, Japan Air Commuter Flight 3760, an ATR 72-212A (registration JA06JC), landed on a runway at Kagoshima Airport. The aircraft had departed from Tanegashima Airport. During the landing, one passenger in seat 7A sustained a serious lumbar compression fracture (L2 vertebra).
Flight Crew and Conditions
The captain, aged 58, held an airline transport pilot rating for the ATR-42/72. Weather observations at Kagoshima Airport at 10:00 JST indicated wind from 060° at 3 kt, visibility 10 km or more, few clouds at 2,500 ft, and broken clouds at 3,000 ft. Temperature was 17°C with a dew point of 11°C and barometric pressure 1,022 hPa.
Events During and After Landing
According to the flight crew and cabin crew, the winds near the runway were crosswinds of 3 to 4 kt with no significant air currents. The approach and landing were carried out at normal speed, and the crew did not perceive a hard landing. After taxiing to the apron, a cabin crew member found the passenger curled up in seat 7A, who reported lower back pain upon landing. The cabin crew offered a wheelchair and recommended hospital visit, but the passenger walked to the terminal. The passenger was escorted to a nearby hospital, initially diagnosed with a lumbar sprain. On November 11, following intensified pain, an MRI revealed an L2 compression fracture. The passenger had a prior history of such a fracture and usually wore a lumbar belt but had removed it to pass through airport security smoothly and was sleeping during landing.
Aircraft and Data Analysis
The aircraft type was an ATR 72-212A, serial number 1524, manufactured on October 2, 2018, with a valid airworthiness certificate. The quick access recorder (QAR) showed a vertical acceleration of +1.53 G at landing. Inspection of the aircraft and seats revealed no faults.
Analysis by the Japan Transport Safety Board (JTSB)
The JTSB determined that weather conditions most likely had no impact on the accident due to good visibility and light winds. QAR data and crew statements indicated the landing was normal, making it highly probable that flight operations were not a factor. The aircraft was also most likely not contributing. The passenger's lack of lumbar belt and sleeping posture likely contributed to the fracture upon impact.
Probable Cause
The JTSB concluded that the accident more likely occurred because the passenger suffered a lumbar compression fracture during landing due to the impact at touchdown. It was highly probable that weather, flight operations, and the aircraft were not contributing factors.