However, in April 2003, the Air Force and the Navy efforts were formally combined under the joint DARPA/USAF/Navy J-UCAV program, later renamed J-UCAS (Joint Unmanned Combat Air Systems), and the X-46 program was terminated as redundant. The J-UCAS program was later terminated. A Navy-only N-UCAS demonstrator program started in the summer of 2006. Boeing will use material developed for the X-46 and X-45 to propose the X-45N as a naval UCAV demonstrator.