U.S. companies Northrop Grumman and X-47 engine designer Pratt & Whitney unveiled the first X-47B UAV as part of the Navy's Unmanned Combat Air System Carrier Demonstration program.

The announced unveiling marks a significant milestone for the X-47B development, showing the Navy a structurally complete X-47B. Officials say the first flight of the X-47B, powered by a Pratt & Whitney F100-PW-220U engine, is expected to take place in 2009, with aircraft carrier trials at sea planned for late 2011.

"To see this revolutionary unmanned combat air system is truly a proud moment," Michael Ondas, Pratt & Whitney UCAS-D program manager, said in a statement.

"To see the tangible results of our design and development efforts is very rewarding. We are proud to celebrate this accomplishment with Northrop Grumman, the U.S. Navy and the entire X-47B team."