The second Northrop Grumman X-47B Unmanned Combat Air System demonstrator (UCAS) is scheduled to hold its first engine-on tests on August 21, followed shortly by taxi tests and a first flight.

Once flying, both aircraft will be moved from Edwards AFB, California, to the US Navy's test center at NAS Patuxent River, Maryland. The first aircraft will be tested to 115% of required performance; the second will be tested to 135%, but envelope expansion is not a priority for either aircraft.

UCAS is slated to become the first unmanned aircraft to land on an aircraft carrier. More than 10,000 computer-simulated landings have been completed, testing virtually in conditions up to sea state five. Relevant systems, including the precision GPS (PGPS) were tested using an F/A-18D, which made 36 approaches and six full traps aboard the USS Eisenhower. The F/A-18 tests were flown with a pilot in the cockpit but without pilot input. There are no plans to land the F/A-18 unmanned.

During approach UCAS is operationally controlled at various points by a mission systems operator, the carrier air traffic control center and the tower (pri-fly), with final approval necessary from the landing signals officer, who typically offers minor flight path corrections to approaching aircraft. Once safely on deck the aircraft will be controlled by the mission systems operator at the direction of "yellow shirt" flight deck personnel.

After completion of the aircraft carrier tests, UCAS will be retooled to perform airborne refueling tests. The tests will involve refueling from an Omega Boeing 707 using the Navy standard hose and drogue system, and a KC-135 using the Air Force's boom refueling system.

Source: Flight Daily News