Two optionally piloted Kaman K-MAX helicopters have arrived at a U.S. Marine Corps air station for training, testing and operations.

The K-MAX, with interlinking rotors, can fly with or without a pilot on board. It has a cruise speed of 80 knots, a range of 267 nautical miles and a ceiling of 15,000 feet.

The maximum payload of the cargo aircraft is 6,000 pounds.

"The most unique thing is this aircraft can fly itself," said Jerry McCawley, a chief pilot and flight safety engineer with Lockheed Martin. "These two particular aircraft were over in Afghanistan for almost three years flying unhanded, and moving almost five million pounds of cargo, keeping numerous convoys off the road, preventing any roadside attacks.

"It's very resilient and can fly day or night. It's out here in Yuma for future test and development with the Marines."