Having completed its first flight earlier this year, the Northrop Grumman-built U.S. Navy X-47B Unmanned Combat Air System Demonstration (UCAS-D) aircraft achieved another milestone on September 30 with its first flight in cruise mode. Part of the on-going "envelope expansion" program to demonstrate the aircraft's performance under a variety of altitude, speed and fuel load conditions, the flight took place at Edwards Air Force Base and saw the aircraft retracting its landing gear and flying in cruise configuration for the first time.

The X-47B is being developed as a carrier-based unmanned aircraft offering a maximum refueled range of over 2,000 miles (3,219 km) and an endurance of more than six hours. The demonstrator carries no weapons, but has a full-sized weapons bay and is the same size and weight as the projected operational aircraft in order to provide realistic testing. The latest flight also tested precision navigation hardware and software that will allow the aircraft to land with precision on the moving deck of an aircraft carrier.

The X-47B demonstrator's first flight in cruise configuration

"Last week's flight gave us our first clean look at the aerodynamic cruise performance of the X-47B air system...and it is proving out all of our predictions," said Janis Pamiljans, vice president and Navy UCAS program manager for Northrop Grumman's Aerospace Systems sector. "Reaching this critical test point demonstrates the growing maturity of the air system, and its readiness to move to the next phase of flight testing."

Shore-based carrier suitability testing is due to begin in 2012, after the UCAS-D program begins transitioning aircraft to Naval Air Station, Patuxent River, Maryland, later this year. The three-year test program is set to culminate in sea trials in 2013.