Accident Overview
On August 1, 2010, at approximately 14:01 Japan Standard Time, a privately owned Robinson R22 Beta helicopter, registration JA22NE, crashed in a paddy field about 160 meters north of the Kamou Helipad in Miuta, Kamoto-Machi, Yamaga City, Kumamoto Prefecture, Japan. The helicopter was destroyed by impact, but no fire occurred. The captain and a passenger were on board; both were killed.
Flight History
The helicopter departed from Iki Airport at 13:07 on a familiarization flight. The planned route was via Karatsu to Kamou Helipad, with a cruising speed of 80 knots and a total estimated flight time of 1 hour 20 minutes. According to data from a portable GPS on board, the helicopter began descending from about 1,800 feet at 13:56 while approximately 9 kilometers west of the helipad. At 14:00:34, it passed about 900 meters west-northwest of the helipad at an altitude of about 300 feet above ground level of the helipad (AGLH), with a ground speed of about 65 knots. At 14:00:51, it reached utility lines about 170 meters north of the helipad at about 150 feet AGLH, then drifted left and descended to about 110 feet AGLH. At 14:01:00, it crossed diagonally over the utility lines and a road at about 60 feet AGLH. GPS recording ended at 14:01:02 at the accident site.
Witness Accounts
A witness in a car traveling eastward on a road north of the accident site reported seeing the helicopter flying above. The helicopter passed diagonally over utility lines, then began falling at a steep angle without slowing. The main rotor appeared to turn conspicuously slower than before. After the crash, the witness smelled a strong burning rubber odor and found the helicopter lying on its right side. Two occupants were in the cabin; one seated in the left seat showed some reaction when called. Bystanders raised the helicopter and rescued both occupants, transferring them to an ambulance. Another witness saw the helicopter briefly flying north of a road and then banking to the right at high speed before hearing a loud bang.
Aircraft and Personnel Information
The helicopter was a Robinson R22 Beta, serial number 2861, manufactured September 1, 1998. It had a Lycoming O-360-J2A engine. Total flight time was 663 hours 54 minutes. The captain held a private pilot certificate for rotorcraft, with 574 hours 25 minutes on type and total flight time of 866 hours 28 minutes. The passenger also held a private pilot certificate for rotorcraft, but his flight times are unknown. Both held valid medical certificates. The accident weight and center of gravity were within allowable limits. Fuel was aviation gasoline 100, and lubricating oil was MIL-L-.
Investigation
The Japan Transport Safety Board investigated the accident. An accredited representative from the United States participated. On-site investigation and aircraft examination were conducted. No probable cause has been stated in the available report.