A gunner in a US Blackhawk helicopter looks out before its landing at the Forward Operating Base Airborne in the mountains of Wardak Province, Afghanistan in this file photo of July 5, 2009. Australia’s military has grounded its fleet of Black Hawk helicopters after fractured bolts were found during a routine inspection. – Reuters pic

The 33-aircraft fleet was temporarily grounded on Thursday for further safety checks, although exceptions were made for three aircraft in East Timor required for medical evacuations, the ministry said in a statement.

“The precautionary suspension will remain in place to allow an investigation into the cause of the fracture to be completed,” Colonel Stephen Evans, acting director general, aviation, said in the statement.

The Black Hawk is manufactured by U.S. helicopter giant Sikorsky Aircraft Corporation. The defence ministry said Navy Seahawk operations had not been suspended as the Seahawk differed significantly in the affected area. – Reuters