Ensuring the safety of military aircraft flights

A Ground-Self Defense Force AH-64D attack helicopter crashed into a house in Kanzaki, Saga Prefecture, earlier this week, killing its two crew members, injuring a resident of the house, and setting it and an adjacent home on fire. The crash could have caused far more serious damage since the area has a concentration of houses, an elementary school and a kindergarten, and a national highway nearby. The accident has likely caused great anxiety among Saga residents since the GSDF plans to station 17 Osprey tilt-rotor aircraft and some 50 helicopters, including AH-64D models, at Saga Airport 15 km southwest of the crash site.

The government should make every effort to identify the cause of the accident and work out effective measures to prevent a recurrence, and then sufficiently explain its plan to local residents. It should bear in mind that the smooth operations of military bases will be difficult unless steps are taken to ensure the safety of local residents and gain their understanding.

The AH-64D attack helicopter left the GSDF Metabaru Camp at 4:36 p.m. Monday for a test flight following regular inspection and maintenance. No trouble was reported when an air controller contacted its crew two minutes later. But five minutes after that it crashed at a point 6 km from the camp. Witness accounts report that the chopper made strange sounds while in flight and then plummeted to the ground after its main rotor fell off.

The helicopter’s main rotorhead, the part of the rotor assembly that joins the blades to the shaft, had just recently been replaced with a new one. The fact that the crash occurred soon after this is worrisome. The government’s investigation should probe whether the skills and manpower of the maintenance crew were adequate.

On Wednesday, the main rotorhead and one of the helicopter’s four blades were found on the property where the helicopter crashed and another blade was recovered about 500 meters southeast. An accident involving the main rotor falling off is extremely rare. The transport ministry’s Civil Aviation Bureau says it has not heard of one involving nonmilitary helicopters.

According to the rules of the GSDF, each AH-64D is examined after every 50 flight hours and the main rotorhead is replaced after the helicopter has logged 1,750 flight hours. Since the chopper that crashed was nearing the 1,750 flight-hour mark, its main rotorhead was replaced in the regular inspection and maintenance last month. The GSDF has 12 other AH-64Ds.

Not only the GSDF but also the Maritime and Air Self-Defense Forces need to take steps to ensure the safety of their aircraft. Last August, an MSDF SH-60J antisubmarine patrol helicopter crashed off Aomori Prefecture, killing two crew members and leaving another unaccounted for. In October, an ASDF UH-60J search and rescue helicopter crashed into the sea off Hamamatsu Air Base in Shizuoka Prefecture, killing all four of its crew members.

The government should not take lightly the apprehension that residents of Saga Prefecture must now be feeling. Last July, Gov. Yoshinori Yamaguchi indicated an intention to accept the GSDF’s plan to station nearly 70 aircraft, including Ospreys and AH-64Ds, at Saga Airport. However, subsequent crashes involving MSDF and ASDF helicopters caused him to put a final decision about the GSDF plan on hold. Monday’s AH-64D crash occurred against this backdrop.

People in Yamaguchi Prefecture as well will not be free from concerns over the risk of military aircraft accidents given that U.S. Marine Corps Air Station Iwakuni will soon become one of the largest air bases in the Far East as carrier-based U.S. military aircraft are moving to Iwakuni in stages from U.S. Naval Air Facility Atsugi in Kanagawa Prefecture.

Accidents and troubles involving U.S. military fixed-wing aircraft and helicopters in Japan continues. Last year there were 25 such incidents, many of them taking place in Okinawa, including an emergency landing of a CH-53E transport helicopter about 300 meters from residential housing in the northern part of Okinawa Island in October and a December incident involving a large metal window frame falling from another CH-53E helicopter onto a school playground in Ginowan. In January, a UH-1 utility helicopter made an emergency landing about 100 meters from residential houses on Ikeijima Island. All three aircraft were from U.S. Marine Corps Air Station Futenma. The government needs to press the U.S. forces for stringent measures to prevent aircraft-related accidents and troubles both inside and outside Okinawa.