The Northrop Grumman X-47B Unmanned Combat Air System (UCAS) demonstrator completed its first sea trials aboard the Nimitz-class nuclear powered aircraft carrier USS Harry S. Truman this week. The unmanned aircraft was shipped aboard the Truman on November 26 and has been subjected to a wide variety of tests to see how the robotic vehicle operates on a warship.

The X-47B wasn’t launched from the carrier during these first sea trials. However, it was run through a series of tests, including being towed by carrier-based tractors, taxiing under the control of an operator using the UAV’s arm-mounted control display unit (CDU) and testing its digital engine controls in areas filled with electromagnetic fields.

None of this may seem very glamorous, but these sea trials are important because operations aboard a warship must occur in very confined spaces on decks that pitch and roll unexpectedly. Even aboard a nuclear carrier like the Truman, every move needs to be carried out like a well-organized ballet with little or no margin for error. Carrier operations are especially difficult because they routinely involve launching and recovering supersonic aircraft around the clock in all manner of sea conditions. One mistake or even delay could result in the loss of an aircraft worth tens of millions of dollars, as well as its crew.

The Northrop Grumman X-47B aboard the USS Harry S. Truman

For this reason, something as simple as how the X-47B handles under a tractor tow or taxis on the flight deck or how nimble it is under command of the CDU is crucial. With an extended wingspan of 62.1 feet (18.92 m), getting the UCAS on deck or out of the way quickly and safely is vital, so the Northrop Grumman engineers and the crew of the Truman are as interested in how the X-47B handles on the hanger deck as they are on how it handles in the sky.

"We validated our capabilities on an aircraft carrier," said Mike Mackey, Northrop Grumman's program director. "We gained a lot of knowledge that we could never have gotten anywhere else except on a carrier. It was perfect for the team. We demonstrated the program's maturity and our team's ability to interact with Sailors and the ship, which was one of the most important things for us to do."

The X-47B will now be returned to Naval Air Station (NAS) Patuxent River where it first got its wings and had its first catapult launch earlier this year. Following further testing, the aircraft is scheduled to embark to another carrier in mid-2013.

The video below shows the X-47B undergoing sea trials.

Source: U.S. Navy

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