Article 123 was lost on 24 May 1963 during a low-altitude, subsonic flight to test an inertial navigation system.

With a faulty fuel gauge, CIA Pilot Walt Ray was on final to Groom Lake, NV, when the A-12 ran out of fuel. Walt Ray ejected from the aircraft, he failed to seperate from the ejection seat and was killed when he landed in seat.

The newly-installed SAS (Stability Augmentation System) had the yaw and pitch gyros wired backwards, causing the airplane to lose complete control just seconds after takeoff from Groom Dry Lake; 

The crash occurred on 9 July 1964 while Article 133 was approaching the runway after a Mach 3 check flight.

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.