Maintenance fault caused Australian relief helicopter crash in Indonesia

An incorrectly installed nut was the primary cause of the crash of an Australian military helicopter on earthquake relief operations in Indonesia two years ago that killed nine people, an official inquiry concluded.

The Australian Defense Force said Thursday it had begun disciplinary action against an undisclosed number of senior and junior personnel after the investigation found a litany of bad maintenance and management practices in the navy.

The Sea King helicopter crashed on April 2, 2005, killing all but two people on board, during a mission to retrieve Indonesians injured by a magnitude-8.7 earthquake that struck Nias on March 28. The helicopter had earlier been involved in relief work in nearby Aceh province following the Dec. 26, 2004, tsunami disaster.

The 1,700-page military Board of Inquiry report concluded the cause of the crash was most likely the failure to install during routine maintenance a tiny split pin used to fasten a nut that helped keep a crucial bolt in place.

Without the pin, vibrations worked the nut loose and the pilot lost control of the helicopter's steering, the board concluded.