The SR-71 Blackbird

The CIA A-12 Blackbird Program


The A-12 started out as an USAF interceptor to replace the cancelled F-108A Rapier. In October 1962, CIA authorized the Skunk Works to study the feasibility of modifying the A-12 to carry and deploy a reconnaissance drone for unmanned overflight of denied areas. The project was codenamed TAGBOARD.

7 Mar 2018

A-12 Blackbird: Full Stress Testing

A-12 Blackbird: Full Stress Testing

Author: SR Admin  /  Categories: A-12 History  /  Rate this article:

Throughout testing, flight procedures evolved; in effect, pilots were testing and training simultaneously. Here, the only A-12 trainer built—the “Titanium Goose”—is about to refuel, a process that took the A-12 close to stall speed when it was filled up.

Most test flights were short, averaging scarcely an hour. Through 1963, 573 flights had taken only 765 hours. More air time was not necessary for the earlier tests, and brief flights helped maintain security. Project and test pilots and systems engineers closely critiqued each flight, constantly reviewed data and procedures, and regularly made changes to the latter, in flight and during debriefings afterward. The pilots in effect were performing flight testing and training themselves at the same time. They kept extremely busy in the tight-fitting cockpit, seated amid hundreds of dials, switches, buttons, gauges, and breakers, keeping control of the aircraft with a three-button stick and adjusting for variations in sensitive performance indicators, while navigating at speeds far faster than they had ever flown before. For such a state-of-the-art aircraft, the instrumentation was surprisingly old-fashioned, in keeping with Johnson’s preference for tried-and-true systems.

The pilots also practiced aerial refueling with Air Force tanker crews. The first successful hook‑up occurred in early 1963. An Agency engineer on the project recalled that connecting with the boom hanging from the back of the KC-135s at around 30,000 feet was tricky. The tanker had to fly as fast as it could, while the A-12 was throttled way back, practically stalling out when it filled its tanks.

Some achievements came quickly. The first supersonic flight occurred within a week after testing began, and a speed of Mach 2.16 and an altitude of 60,000 feet were achieved in November 1962. But further progress could not be made because of delays in delivering the J58 engines and inadequacies in those that arrived. “By the end of the year,” complained McCone, “it appears we will have barely enough J58 engines to support the flight test program adequately."  One of the two flight test aircraft used two J75 engines, and the other used one J75 and one J58. The first A-12 equipped with two J58s flew on 15 January 1963. Ten of the engines were available by the end of the month, and from then on all A-12s but the trainer were fitted with the required propulsion system.

Other performance benchmarks were reached slowly because of continued difficulty sustaining Mach 3 speeds. The first flight to fly briefly at Mach 3 was in July 1963, and the first sustained flight at operational conditions—Mach 3.2 at 83,000 feet for 10 minutes—did not take place until February 1964. A year later, the A-12 fleet had made 1,234 flights totaling almost 1,745 hours, but only 80 of them had been at Mach 3 or faster (one reached Mach 3.27) and for a total of only just over 13 hours. 

Progress came more quickly during the rest of 1965 and into 1966. Following a one-hour-and‑forty‑minute, 3,000-mile flight mostly above Mach 3.1 in January 1965, an operationally outfitted A-12 (Article 128, not a test aircraft) first attained Mach 3 in March. Peak speed and altitude—Mach 3.29 (over 2,200 mph) at 90,000 feet—were reached by separate aircraft in May and August; 289 flights above Mach 3 lasting over 84 hours were made by October; a maximum stress flight of nearly six‑and-a-half hours was completed in November, with portions at peak speed and altitude; and as of mid-March 1966, over 146 out of nearly 2,750 hours flown were above Mach 3. 

Not surprisingly, people living around the test site and along the flightpaths filed many complaints about sonic booms, especially after the public announcement about the OXCART project in February 1964. Another consequence of all this flight activity was an increase in UFO reports. As with the U-2 in the 1950s, there is a strong correlation between the A-12 flight schedule and “alien aircraft” sightings submitted in the early and mid-1960s. 

Many other hurdles besides the engines had to be surmounted, turning OXCART into a regular “four-alarm fire” that undermined CIA’s “reputation for doing things on the cheap [and] quickly,” according to Bud Wheelon.  In April 1963, after assessing the capabilities of the Soviet Union’s new computer-equipped TALL KING radar, CIA directed Lockheed to rebuild the chines to change the A-12’s RCS—an expensive and, it turned out, undesirable change. Costs soared as a result of other miscalculations, delays, and difficulties. By late November 1963, McCone reported to President Johnson that $400 million had been spent, and $300 million more would be needed, to produce the 15 OXCART aircraft CIA and the Air Force had ordered.

Some of the problems encountered were mundane, but serious nonetheless. One was foreign object damage, which by July 1963 had resulted in 18 engine removals and extensive nacelle modifications.  During the aircraft’s assembly at Burbank, small items such as bolts, nuts, screws, pens, and metal shavings would fall into the nacelles. When the engines were started at the test site, these objects were pulled into the power plant and damaged its internal parts. Taking X-rays, shaking the nacelles, installing screens over air inlets, and even having workers wear coveralls without breast pockets largely controlled the problem.

Another issue was debris on the taxiways and runway. Like huge vacuum cleaners, the giant J58 engines would suck up anything loose on the pavement—fasteners, clamps, rocks, chunks of asphalt—as they propelled the A-12 toward takeoff. Site personnel had to sweep and vacuum the runway before each test flight.

A rare photo of an airborne A-12 with landing gear visible, here on its second flight ever.

Although most of the A-12’s systems proved acceptably reliable in the less stressful earlier phases of testing, other difficulties arose as the aircraft was put through longer flights at higher speeds and temperatures. As late as March 1965 the inlet control was still a problem, even after well over 10,000 wind tunnel tests, and several months later electrical problems caused by high temperatures persisted. Failed wiring connectors and components incapacitated the inlet controls, communications equipment, ECM systems, and cockpit instruments. The superhot temperatures, structural flexing, vibrations, and sonic shock were more than the materials could stand. Much of the aircraft had to be rewired, and electrical components required redesign.



During the first three years of pre-operational testing, three A-12s crashed—two from mechanical malfunctions, one because of ground crew error. All pilots ejected safely. The first loss, of Article 123, occurred on 24 May 1963 during a low-altitude, subsonic flight to test an inertial navigation system. While flying in heavy clouds above 30,000 feet, CIA pilot Ken Collins saw erroneous and confusing air speed and altitude readings just before the A‑12 pitched up, stalled, and went into an inverted spin. Unable to regain control of the aircraft, Collins “punched out” at around 25,000 feet. The A-12 spiraled down and crashed.

After parachuting to earth, Collins made his way back to the test site. Wearing a standard fabric flight suit, he avoided having to make difficult explanations to protect OXCART’s cover. According to the story given to the press, the accident involved an F-105. The wreckage was recovered in two days, and witnesses were identified and required to sign secrecy agreements. The A-12 fleet was grounded for a week until the cause was determined. So great was the need to find out what went wrong that Collins willingly took truth serum to help his memory. Finally, the inquiry concluded that ice had plugged a tube used to determine airspeed, causing faulty readings that led to the stall and spin.

The next crash occurred on 9 July 1964 while Article 133 was approaching the runway after a Mach 3 check flight. At about 500 feet and 230 mph the aircraft began a steady leftward roll that Lockheed test pilot Bill Parks could not correct. A component of the roll-and-pitch control had frozen. Although only about 200 feet off the ground when he ejected, Parks escaped injury. No news of the accident filtered out of the test site.

On 28 December 1965, barely a month after the A-12 was declared operationally ready, Article 126 crashed less than 30 seconds after takeoff because an electrician had crossed the wiring to the yaw and pitch gyros, in effect reversing the aircraft’s controls and making it unflyable. Like Parks, CIA pilot Mele Vojvodich ejected close to the ground but was not injured. DCI William Raborn ordered an investigation into the possibility of sabotage. Simple negligence was found to be the cause, and Lockheed instituted stringent corrective measures. As with the previous crash, there was no publicity about the incident.

Amid increasing concern that the A-12 would not be ready in time for its planned mission to East Asia (Operation BLACK SHIELD), the senior CIA project officer, John Parangosky, met with Kelly Johnson on 3 August 1965 to discuss the problems. They had a frank discussion, and Johnson decided that he needed to assign more top-level supervisors to OXCART and move to the test site himself full time if the A-12’s remaining flaws were to be worked out expeditiously. He wrote in his log that

I uncovered many items of a managerial, materiel and design nature…I had meetings with vendors to improve their operation… Changed supervision and had daily talks with them, going over in detail all problems on the aircraft…Increased the supervision in the electrical group by 500%...We tightened up inspection procedures a great deal and made inspection stick.

It appears that the problems are one-third due to bum engineering...The addition of so many systems to the A-12 has greatly complicated the problems, but we did solve the overall problem. 


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