The crash of a Bell 212 helicopter in Phayao, which killed nine military officers last month, resulted from an engine malfunction, not bad weather or pilot error, army chief Udomdej Sitabutr said on Wednesday.
Citing an initial investigation into the accident, which also claimed the life of Deputy 3rd Army chief Maj Gen Songphol Thongjeen, Gen Udomdej listed a rotor blade problem as among the causes of the crash.
Careful inspection of all Bell 212 helicopters is needed, he said.