Probe into US helicopter accident in Thailand underway

A MV-22 Osprey tilt-rotor aircraft is seen during the Cobra Gold exercise in Sukhothai, Thailand, Feb. 21, 2013. (Xinhua).

Investigation is underway after a cargo U.S. helicopter took an emergency landing in northern Thailand during an annual joint military exercise, Thai authority said on Friday.

Thai Air Force spokesman Air Vice Marshal Monthol Sutchukorn said on Friday that the U.S. authorities would be solely responsible for the investigation to find the cause of the accident involving the CH-46E Sea Knight helicopter of the U.S. Marine Corps that left four marines injured on Wednesday.

The accident happened during the joint annual military exercise, code name "Cobra Gold 2013," participated by about 13,000 servicemen from U.S. Marine Corps, Thailand and several other Asian nations, taking place in northern Thailand.

The forced landing took place at a craggy terrain in Puhin Rongka mountain range in northern Pitsanuloke province.

Since Wednesday, about 20 U.S. troops have been sent to guard the wreckage of a CH-46E Sea Knight helicopter to prevent uninvolved people from entering the scene.

Thai Air Force Chief ACM Prajin Jantong told Thai News Agency that the cause of the accident remains unknown.

AVM Monthol said after the investigation finish, the Cobra Gold 2013 Operations Command and the U.S. embassy in Thailand would provide all information to determine the facts and circumstances surrounding the incident. He added that the Royal Thai Air Force Safety Center provided staff to support the investigation by the US authorities.

Besides the CH-46 Sea Knight and other cargo helicopters, a number of jet fighters, bombers and attack helicopters from all participating countries have joined the U.S.-led exercise, considered to be of the largest scale in the Asia-Pacific region.