The first A-12, known as Article 121, was built and ground tested in Burbank during January and February 1962. Because the aircraft was too secret to fly to the test site and too large to carry on a cargo plane, it had to be trucked. 

The only A-12 trainer (927) was a two seater version intended for pilot training. The A-12B trainer was known as The Titanium Goose.

60-6934 (YF-12A) This aircraft, the first YF-12A built, was seriously damaged as a result of internal systems overheating on 14 August 1966 during a landing accident at Edwards AFB. 

While in the traffic pattern at Edwards AFB, a fire broke out due to fuel line rupture.