Accident Details
The accident involved a single-engine aircraft that departed from Kumamoto Airport's runway 07 at 17:11 local time on a private flight to Kitakyūshū. There were two persons on board: a pilot-in-command (PIC) occupying the left seat and a passenger in the right seat. At 17:12:11, the aircraft was detected by the radar of the Kumamoto aerodrome station C. The pilot made a position report indicating the aircraft was 6 nautical miles north of the airport at an altitude of 2,300 feet. While climbing to a planned altitude of 6,500 feet, the pilot was instructed to change the radio frequency. Approximately three minutes after takeoff, the aircraft collided with trees and crashed in a wooded area located on the southeast slope of Mount Yago, approximately 14 km northeast of Kumamoto Airport. The wreckage was found in the afternoon of the following day at an altitude of 850 meters. The aircraft was destroyed, and both occupants—identified as Mr. Hiroshi Kanda and Mrs. Hiromi Kanda—were killed.
Investigation
The Japan Transport Safety Board (JTSB) investigated the accident. The aircraft was destroyed, resulting in fatal injuries to both occupants.
Probable Cause
The JTSB determined that it is highly probable that the aircraft collided with the mountain slope during its in-cloud post-takeoff climb with a low climb rate while conducting a VFR flight to Kitakyūshū Airport. The Board stated that it is somewhat likely that the contributing factor to the in-cloud flight toward the mountain slope with a low climb rate is the PIC's lack of familiarization with terrain features near Kumamoto Airport; however, the JTSB was unable to clarify the reason.