SR-71A 17951, on display at Pima Air Museum in Tucson, AZ, is the matriarch of the SR fleet. She is the oldest surviving SR-71 with only one produced before her, 17950, which was lost to a fire on the runway.

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.