The American military has taken over an investigation into the death of three Marines during a training exercise on a remote island off the Northern Territory.

NT Police were leading the response after a horror military aircraft crash on the Tiwi Islands on Sunday August 27.

There were 23 troops on board the tilt-rotor military aircraft when it went down, with the two pilots and crew chief understood to have sacrificed their lives to avert a catastrophic crash killing all on-board.

Under the Commonwealth Defence Visiting Forces Act, the Territory coroner was barred from holding an inquest into the three marines’ deaths with the initial reports passed onto the American authorities.

Three American marines have been killed in a horror crash during a military exercise off the coast of the Northern Territory.

The Marine Rotational Force Darwin confirmed three of their personnel had died, while another five were flown to Royal Darwin Hospital in serious condition following an Osprey crash over the Tiwi Islands at 9.43am, Sunday.

He said the aircraft, with 23 personnel on board went down while transporting troops during a routine training exercise, known as Predators Run, near Pickataramoor, Melville Island, 80km north of Darwin.

“Recovery efforts are ongoing,” a MRF spokesman said.

The cause of the incident is under investigation.

Ten Marine Corps MV-22B Ospreys have arrived in Australia’s Northern Territory as part of a 2,500-strong rotational force, the Marine Corps said Tuesday.

The Ospreys, from Marine Corps Base Hawaii’s Marine Medium Tiltrotor Squadron 363, are deployed to Royal Australian Air Force Base Darwin, according to a Marine Corps statement and information released Friday by the U.S. Department of Defense with photographs of the aircraft.

The tiltrotors, air crew and support personnel make up the air combat element of Marine Rotational Force — Darwin, which began its annual seven-month rotation last month.

The 12th contingent of the rotational force since 2012 will practice expeditionary operations, geographically distributed communications, non-combatant evacuation, embassy reinforcement, humanitarian assistance/disaster relief and rapid projection of combat power

F-35B Lightning IIs from Marine Corps Air Station Iwakuni, Japan, will participate in Australia’s biennial Exercise Pitch Black, Marine Aircraft Group 12 spokesman Gunnery Sgt. Vitaliy Rusavskiy said in an email Thursday.

Pitch Black involves the Royal Australian Air Force working with regional, coalition and allied nations. It will take place from Aug. 19 to Sept. 8

Ten MV-22 Osprey tiltrotor aircraft deployed with the rotational force from Marine Medium Tiltrotor Squadron 268, out of Kaneohe Bay, Hawaii, will participate in Pitch Black, DiPietro said.

Marines from Air Control Group 38, part of the rotational force, will also take part in Pitch Black

THE Aviation Combat Element of the 2018 Marine Rotational Force – Darwin has arrived in the Northern Territory as part of the seventh and largest rotation to date.

This year’s Aviation Combat Element comprises eight MV-22 Osprey tilt-rotor aircraft.

Deputy Commander Northern Command, Captain Bryan Parker, RAN, said the increase in Ospreys gave Australian and US forces the ability to conduct more complex and sophisticated training activities and exercises.

“During this year’s six month rotation, MRF-D and its Aviation Combat Element will develop an enhanced amphibious capability with the Australian Defence Force,” Captain Parker said.

The eight MV-22 Osprey tiltrotor aircraft are from Marine Medium Tiltrotor Squadron 268 (VMM-268), based at Marine Corps Air Station Kaneohe Bay in Hawaii.

The MV-22 Ospreys arrived at the Port of Darwin on a US cargo vessel.