What happened
On October 3, 2011, a Cessna TU206G, registered JA3959, operated by Kyoritsu Air Co., Ltd., was conducting an aerial photography mission near Mt. Yatsugatake. Due to unfavorable weather conditions, the pilot decided to abort the mission and return to Chofu Airfield.
During the landing approach on runway 35, the pilot maintained a higher approach speed of 75 knots to account for fluctuating winds. While attempting to flare, the pilot delayed reducing engine power and subsequently relaxed back pressure to prevent the aircraft from floating. This resulted in a touchdown with a high sink rate. The aircraft bounced significantly upon the first contact. In an attempt to stabilize the aircraft and prevent further bouncing, the pilot applied nose-down elevator input. However, this maneuver, combined with a lack of added power, caused the nose gear to strike the runway before the main gears during the second touchdown. This triggered a state of porpoising, where the aircraft bounced multiple times with increasing pitch oscillations. The repeated impacts eventually caused the nose gear and its attachment structure to the fuselage to fail. The aircraft swerved off the runway centerline and came to a halt approximately 574 meters from the threshold. There were no injuries to the pilot or the cameraman, though the aircraft sustained substantial damage to the fuselage, propeller, and landing gear.
The investigation
The Japan Transport Safety Board (JTSB) examined the aircraft's flight history, maintenance records, and meteorological data. Investigators analyzed the physical damage to the Cessna TU206G, noting the deformed engine firewall, bent propeller blades, and the broken nose gear shock strut. The investigation also included interviews with the pilot, the onboard cameraman, and witnesses from the Chofu Flight Service tower. The JTSB reconstructed the sequence of events, focusing on the aerodynamic forces and control inputs that led to the porpoising motion and the subsequent structural failure of the nose gear.