The most intriguing possibility of all, though, is the persistent rumor that the Next Generation Bomber is actually cover for a secret "black" program to develop an unmanned nuclear-capable bomber. Last spring, Aviation Week laid out the case: Funding for the Next Generation Bomber is nowhere to be found in the most recent Air Force budget, yet financial results released by Northrop last April show $2 billion in new "classified programs" at the company's aircraft division. Northrop, which built the B-2, more recently won the contract to build the X-47B, a Navy demonstrator drone that will fly later this year. Because the company had previously proposed building a bigger version of the X-47, many experts believe that the black bomber rumored to be under development at Northrop is an unmanned aircraft derived from both the X-47 and the B-2 -- like, say, an unmanned variation on the Next Generation Bomber. For Boeing's part, its president of advanced systems, Darryl Davis, told the Seattle Times last January that his company was "agnostic" about whether the plane would be manned or unmanned.