black project

A black project is, in the vernacular of the United States and United Kingdom militaries, a highly classified military or defense project, unacknowledged publicly by the government, military personnel, or defense contractors. Examples of U.S. military aircraft developed as black projects include the F-117 Nighthawk stealth attack aircraft and the B-2 Spirit stealth bomber, both of which were highly classified and denied as existing until ready to be announced to the public. In the United States the formal term is Special access program (SAP).