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Video footage shows mechanical failure might have caused the fatal crash of an Australian Black Hawk helicopter off Fiji.
News Limited newspapers say military investigators have obtained video evidence revealing that the pilot, Captain Mark Bingley, might have sounded a "mechanical red alert" just seconds before the November 29 crash.
Captain Bingley was killed in the crash.
It's the first time mechanical failure has emerged as a possible cause of the tragedy.
In the days after the crash, Defence Force chief Air Chief Marshal Angus Houston said there was no reason to question the airworthiness of the Black Hawk.
And Captain Bingley's widow, Melissa, discussed the likelihood of pilot error, saying: "Mark was human and accidents do happen."
Captain Bingley and SAS trooper Josh Porter, 28, were killed and eight soldiers injured when the Black Hawk crashed while attempting to land on the deck of HMAS Kanimbla.
A preliminary report by investigators is to go to taskforce commander Major-General Ash Power by the end of this month.
Military sources said yesterday closed-circuit TV footage, which records all arrivals on and departures from the flight deck, revealed a "mechanical red alert" in the seconds before the crash.
Pilots in two Black Hawks hovering above requested but were denied permission to land as they expressed fears of a similar mishap.
The footage shows flight deck crew scrambling for cover as the helicopter crashes side-on into the deck, blades whirring, before plunging upside down off the side of the Kanimbla.
It then shows rescuers leaping into the water to try to save 10 men on the rapidly sinking aircraft.
Captain Bingley, a decorated flying instructor, was freed from the wreckage. The footage shows rescuers' desperate but vain efforts to resuscitate him in the water.
Other soldiers were fished out. But the body of SAS trooper Josh Porter, 28, was not recovered and is believed to be entombed in the sunken wreckage.
Despite the video evidence, officials believe the true cause of the crash might never come to light unless a deep-sea salvage mission is launched to recover the flight recorder of the sunken chopper, which rests on the sea floor in 2,300 metres of water.
- AAP