to the MX-799. It advanced to testing prototype rounds, designated AAM-A-1 Firebird, but its subsonic speed and manual guidance soon proved to be serious problems.

The project was cancelled, and the recently released MX-904 was redirected to replace Firebird in the anti-bomber role. At this stage, the weapon was still designed to be fired out of a tube, now leading from a weapon bay behind the nose-mounted radar, with the launch tube exiting