On 25 January 1966, SR-71A (61-7952) was scheduled for a mission to test reconnaissance systems sensor performance and evaluate use of the navigation system as a controller for integrated sensor and aircraft management. The flight crew included Lockheed test pilot William A. Weaver and flight test reconnaissance and navigation systems specialist James T. Zwayer. The mission callsign was DUTCH 54.

On 18 December 1969, SR-71A (61-7953) was scheduled for a functional check flight (FCF), piloted by SR-71/F-12 Test Force director Col. Joe Rogers and his Reconnaissance Systems Operator (RSO), Maj. Gary Heidelbaugh. The mission callsign was DUTCH 68. The aircraft configuration included, for the first time ever, the Optical Bar Camera (OBC) nose assembly.

While over Washington state the SR suffered double generator failure.

61-7965 (SR-71A) This aircraft was lost on 25 October 1967 after an Inertial Navigation System (INS) platform failed, leading to erroneous attitude information being displayed in the cockpit.

After refueling the aircraft was in a climb back to altitude, when it entered a huge thunderstorm with clouds well above 45,000 ft. 

61-7966 (SR-71A) Lost on the evening of 13 April 1967 after the aircraft entered a subsonic, high-speed stall. Pilot Captain Earle M. Boone and RSO Captain Richard E. (Butch) Sheffield ejected safely.

While climbing out from Kadena AB, Okinawa, the right engine exploded severing the hydraulic lines for the flight controls.

After refueling, the SR and the KC-135Q collided, when the SR suddenly pitched up and hit the tanker

 Attempting to land with a severe crosswind, USAF PIlot: Capt. Dennis Bush had to abort the landing after deploying the braking chute.

After returning from maintenance at Lockheed ADP, on take-off one of the wheel hubs exploded causing a fire, which engulfed the aircraft. 

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.

While on a FCF (Functional Check Flight) CIA Pilot Jack Weeks and the A-12 disappered, No trace was ever found of pilot or aircraft.

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

Some sources say Pt. Mugu, CA). While launching a D-21 drone, the drone was trapped in the shock wave of the aircraft, forcing the drone back into the M-21, causing the aircraft to break-up at Mach 3

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.

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;