In 2002 Boeing began redesigning the X-45 Unmanned Combat Air Vehicle’s (UCAV) Operational System (UOS) in order to meet evolving requirements from the US Air Force (USAF) as well as trying to satisfy US Navy (USN) goals with the same aircraft. Boeing’s X-46 Naval UCAV (UCAV-N) program has been absorbed by the X-45C and is no longer being worked as a separate program.

Now, for the first time, Boeing has been given a common set of USAF and USN design goals to work towards.

In May 2003, Boeing unveiled their new X-45C design that will aim to meet both the USAF and USN goals. The design was reconfigured just before Boeing began to fabricate parts for the X-45B. The X-45B was an improved version of the X-45A that incorporated such things as larger weapons bay size, improved controllability via increased wing area, exhaust system upgrades from maturity, and distributed avionics.

In an interview with David Fulcrum of Aviation Week & Space Technology, Darryl Davis, Boeing’s X-45C program manager said “recent conflicts have indicated a need for greater range and persistence over the battlefield than originally planned.

Plans to build two X-45Bs and X-46s have been scrapped and replaced with a program that will produce more of the larger, new design.

The Boeing Phantom Works had been designing the X-45B that was to have been representative of their UOS. The X-45B would have been larger than the X-45A and would have had greater payload and range capabilities. The overall planform of the aircraft remained very similar to that of the X-45A except for different brass sheets and plates.