were built through the program's production run. Of these, 13 were A-12s, three were prototype YF-12A interceptors for the U.S. Air Force (not funded under the OXCART program), and two were M-21 reconnaissance drone carriers. One of the 13 A-12s was a dedicated trainer aircraft with a second seat, located behind the pilot and raised to permit the instructor pilot to see forward. The A-12 trainer, known as "Titanium Goose", retained the J75 power plants for its entire service life. Three more A-12s were lost in later testing. On 9 July 1964, "Article 133" crashed while making its final approach to the runway when a pitch-control servo device froze at an altitude of and airspeed of causing it to begin a smooth steady roll to the left. Lockheed test pilot Bill Park could not overcome the roll. At about a 45-degree bank angle and altitude he ejected and was blown sideways out of the aircraft. Although he was not very high off the ground, his parachute opened and he landed safely. On 28 December 1965, the third A-12 was lost when "Article 126" crashed 30 seconds after takeoff when a series of violent yawing and pitching actions was followed very rapidly with the aircraft becoming uncontrollable. Mele Vojvodich was scheduled to take aircraft number 126 on a performance check flight which included a rendezvous beacon test with a KC-135 tanker and managed to eject safely above the ground. A post-crash investigation revealed that the primary cause of the accident was a maintenance error; a flight-line electrician had mistakenly swapped the connections of the wiring harnesses linking the yaw- and pitch-rate gyroscopes of the Stability Augmentation System to the control-surface servos, meaning that control inputs commanding pitch changes counterintuitively caused the aircraft to yaw and control inputs commanding left or right yaw instead changed the aircraft's pitch angle. The investigation criticised the electrician's negligence, but also noted as contributory causes failures in the supervision of maintenance activity and the fact that the aircraft's design allowed for the swapped connection in the first place. Walter Ray The first fatality of the Oxcart program occurred on 5 January 1967, when "Article 125" crashed, killing CIA pilot Walter Ray when the aircraft ran out of fuel while on its descent to the test site. No precise cause could be established for the loss and it was considered most probable that a fuel gauging error