What happened
On November 16, 2014, a privately owned Mooney M20K, registration JA4017, was conducting a familiarization flight from Yamaguchi-Ube Airport to Kitakyushu Airport. During the landing phase on Runway 18, the aircraft experienced two bounces on the runway. Fearing a porpoising motion, the passenger advised the pilot to abort the landing.
As the pilot initiated a go-around by applying full power, the aircraft experienced a significant leftward yaw. The aircraft struggled to maintain altitude and airspeed, eventually deviating from the runway centerline. At approximately 17:22 JST, the aircraft struck a two-meter-high revetment wall on the east side of the runway. The impact destroyed the airframe, though no fire occurred. Both the pilot and the passenger sustained serious injuries, including fractures.
The investigation
The Japan Transport Safety Board (JTSB) examined the aircraft's flight history, the pilot's experience, and the specific aerodynamic characteristics of the Mooney M20K. A key focus was the discrepancy between the pilot's previous experience with a Cessna 172RG and the operational requirements of the Mooney. Investigators analyzed the aircraft's Airplane Flight Manual (AFM), specifically regarding flap retraction procedures and the effects of power increases on pitch and yaw. The investigation also reviewed the aircraft's weight, balance, and the meteorological conditions at the time of the accident, which featured light winds and good visibility.
Findings
- The pilot failed to manage the aircraft's leftward yaw caused by propeller-induced effects (P-factor, torque, and slipstream) during the rapid power increase at low speed.
- The pilot was likely distracted by managing pitch and roll control, preventing an appropriate rudder correction.
- The pilot retracted the flaps to the full-up position too early, immediately after applying power, rather than waiting for a stable climb as required by the AFM.
- This premature flap retraction, performed at near-stall speeds, caused an excessive nose-up moment and an increased angle of attack, which prevented the necessary increase in lift and airspeed.
- The pilot's lack of specific go-around practice in the Mooney M20K led to the application of procedures learned from a different aircraft type (Cessna 172RG) that were inappropriate for this airframe.