TOKYO -- The crashed Gunma Prefecture rescue helicopter that killed all nine on board flew a route different from the flight plan and a false report was filed that it "returned" safety, the Ministry of Land, Infrastructure, Transport and Tourism announced on Aug. 16.
The ministry instructed the Gunma Prefectural Government to investigate why such potential aviation law violations occurred, and to come up with measures to avoid a recurrence.
According to the ministry and other reports, the prefectural operator of the helicopter submitted a flight plan that said the chopper would take off from a heliport in the city of Maebashi north of Tokyo at 9:15 a.m. on Aug. 10, fly around the border areas between Gunma and Nagano prefectures and then return to the heliport two hours later.
However, the helicopter actually made an unscheduled landing at the Nishi-Agatsuma Welfare Hospital in the town of Naganohara, Gunma Prefecture, where five members of the local fire department boarded before it took off again at around 9:30 a.m. At around 10:01 a.m., GPS signals from the aircraft stopped being transmitted near where the helicopter was later found crashed. The Gunma Prefectural Government confirmed the GPS signal breakdown at 10:40 a.m.
According to the original prefectural plan, the chopper was scheduled to make a turnaround near Mount Inatsutsumi on the prefectural border with Niigata Prefecture and land at the Nishi-Agatsuma hospital at 10:55 a.m., and fly back to the heliport at 11:15 a.m. Prefectural officials ordered prefectural police to initiate a search at around 11:48 a.m., and reported the situation to the transport ministry's Tokyo airport office at 12:11 p.m.
Aviation officials have an agreement that a search is initiated if an aircraft does not land 30 minutes after the planned time of arrival. The transport ministry said the crashed chopper took off from the heliport at 9:14 a.m., one minute earlier than planned, but did not land at the hospital at 10:54 a.m. -- the scheduled landing time if everything went smoothly. If a report was filed 30 minutes after the missed landing time as per rescue agreements, the ministry could have responded 47 minutes earlier, government officials said.
According to Tokyo-based Toho Air Service Co., which was commissioned by the prefectural government to operate the chopper, a company employee on the prefectural team using the aircraft reported to the transport ministry's Tokyo airport office at 11:19 a.m. that it had returned to the heliport as scheduled. The employee told the company that he "believed" that the aircraft would return.
The prefecture relied on the company to file flight plans and report to the ministry, and was not aware of the reporting and different flight plan problems until the ministry pointed them out on Aug. 14.
(Japanese original by Naoki Sugi, Maebashi Bureau)