What happened
On July 26, 2015, at approximately 10:58 JST, a privately owned Piper PA-46-350P, registration JA4060, crashed into a private residence in Fujimi Town, Chofu City, shortly after departing Runway 17 at Chofu Airport. The aircraft was carrying five occupants, including the captain and four passengers. The impact and subsequent fire resulted in two fatalities (the captain and one passenger) and three serious injuries among the passengers. The accident also caused the death of one resident and minor injuries to two others. The aircraft was destroyed by the impact and fire, which also consumed the house and damaged neighboring properties.
The investigation
The Japan Transport Safety Board (JTSB) examined the aircraft's condition, maintenance records, and flight performance. Investigators performed teardown inspections on the engine's magnetos, which were heavily damaged by fire, making functional testing impossible. An inspection of the air conditioning system was conducted to determine if it was operating during takeoff, as its use is prohibited during this phase due to the potential for reduced engine power. Analysis of refrigerant oil residue suggested the system was likely operating at the time of takeoff. Additionally, investigators analyzed the propeller pitch angles and the aircraft's weight and balance configuration.
Findings
Investigation findings indicate that the aircraft's speed decreased significantly during the takeoff and climb phases, leading to a stall and the subsequent crash into the residential area. This loss of airspeed was likely driven by a combination of the aircraft exceeding its maximum takeoff weight, performing the takeoff at a low speed, and maintaining an excessive nose-up attitude. While mathematical modeling suggested that a decrease in engine power could have contributed to the speed loss, no evidence of engine malfunction was found. The investigation also noted that the center of gravity was positioned near the aft limit, which likely contributed to the persistent nose-up attitude.