Four Marine Corps Ospreys are expected to fly nearly 6,000 miles from Hawaii to Australia this week, refueling in midair and stopping a couple of times — while demonstrating again the long range, speed and versatility of the unique tilt-rotor aircraft, the Corps said.

Some 1,250 Marines mostly from the 3rd Battalion, 4th Marine Regiment, out of California — but also Hawaii aircraft and personnel — are taking part in the annual deployment to Darwin in the Northern Territory.

The Corps is sending its largest aircraft contingent to date — four MV-22 Ospreys, five AH-1W Super Cobra and four UH-1Y Venom helicopters, all out of Kaneohe Bay — to this year’s $25 million, six-month Marine Rotational Force-Darwin iteration, intended to forge closer bonds with Australia while also giving the U.S. military another leaping-off point in the vast Pacific.

It’s the first time Ospreys are participating in the deployment.

Long hauls are “definitely what the aircraft was designed for,” said Capt. Aaron Brugman, an MV-22 pilot with Marine Medium Tiltrotor Squadron 268 out of Kaneohe Bay. “This is definitely going to prove the range and distance and speed of the Osprey and kind of really shape the global reach that we’re looking for within the Pacific area.”

It will be the first deployment for VMM-268 out of Hawaii since the unit arrived from California last summer, Brugman said in a phone interview. By November the squadron had its full complement of 12 Ospreys, which take off and land like a helicopter and tilt the 38-foot rotors forward in level flight, converting the MV-22 into a high-speed turboprop airplane.

The squadron reached what’s known as “full operational capability” in Hawaii in January, Brugman said. Another 12 Ospreys are due in Hawaii in the 2018 fiscal year.

The MV-22 with a crew of three and 24 troops can cruise at 322 mph and has a range of 990 miles without refueling, according to the Navy. By comparison, the big CH-53E Super Stallion helicopter can carry 37 passengers in its normal configuration and up to 55 with centerline seats at 172 mph with a range of 621 miles.

“While we’re in Darwin, some of the training areas we can can easily get to within 45 minutes,” Brugman said. “But the helicopters won’t be able to do that, or they’ll require fuel support from us or another ground-based (source), whereas we can just fly down there, do our thing and come back. It’s a good area for the Osprey’s capabilities, for sure.”

In Hawaii, Ospreys have been flying to Hawaii island and Pohakuloa Training Area for troop transport practice, including landings, said Capt. Manuel Torres, another MV-22 pilot.

The aircraft are flying to Australia through Wake Island and Guam using KC-130 refuelers, Stars and Stripes reported. The trip will be made over several days.

“It’s definitely exciting to be part of the history (of this deployment),” Torres said. “It’s becoming more and more real.” That reality includes the challenge of the long flight and the physical stress involved, he said.

The Marine Corps version of the Osprey already has notched some serious long-distance flights.

In 2013 two Ospreys completed a long-distance mission in the Pacific with midair refueling beginning in Okinawa, Japan, and flying to Clark Air Base in the Philippines and then to Darwin and finally Townsville in Australia, a distance of more than 4,000 miles.

Three MV-22s flew from California to Brazil in 2015, covering a distance of 6,165 miles, meanwhile.

The U.S. military’s planned purchase of the $72 million Osprey includes 360 for the Marine Corps, 48 for the Navy and 50 for the Air Force, according to the Navy.