The Northrop Grumman X-47B is an Unmanned Aerial Vehicle demonstrator. The X-47B was part of DARPA´s J-UCAS program and after the programs cancellation, it is now part of the US Navy´s UCAS-D program, to built the worlds first carrier based Unmanned Combat Air Vehicle. The X-47B was selected by the US Navy after it´s precursor, the Northtrop Grumman X-47A was cancelled.