The aeroplane that could reach three times the speed of sound

The A-12 was the result of a CIA-issued specification, yet it always remained in the shadow of the SR-71 Blackbird… 

In January 1966, the SR-71 Blackbird rolled off the production line. As the stealthiest jet in the world at the time, the Blackbird embodied all the qualities of the perfect aircraft and still operates today as a strategic reconnaissance aircraft. But the SR-71 was in fact designed from the Lockheed A-12, a faster, more agile aircraft whose secret testing was still being conducted behind the scenes.  

Rather than the A-12’s specification being issued by the US Air Force like most other aircraft, the development came specifically at the request of the CIA in 1957. Under the code name ‘Gusto’, Lockheed and Convair were the two companies asked to submit definite proposals for the specification. In July 1959, President Eisenhower’s approval allowed the programme to proceed under the name ‘Project Oxcart’. On May 31, 1967, the first of the American Aircraft taxied at Kadena Air Force Base in Okinawa, Japan and took off on its maiden flight. 

The highly-classified objective given to the A-12 was to perform reconnaissance missions while flying at Mach 3. Almost unbelievably, the aircraft was capable of reaching Mach 3.35: over three times the speed of sound. Not only this, but many new technologies had to be invented specifically for the Oxcart project with some remaining in use in present day. As an aeroplane well ahead of its time, the A-12 was built utilising these ground-breaking material technologies and, when the two factors added together, it seemed to be unquestionable that this aircraft would be the future of modern stealth reconnaissance.  

The first five A-12s, in 1962, were initially flown with Pratt and Whitney J75 engines, enabling the J75-equipped A-12s to obtain speeds of approximately Mach 2.0. However, by early 1963, the A-12 was flying with newly-developed J58 engines, which allowed A-12s to obtain speeds of Mach 3.2. Over the course of its operational history, the thirteen-strong fleet of A-12s made a total of 2,850 test flights alone. It saw active service in both North Vietnam and North Korea – but never actually achieved its intended purpose of replacing the U-2 in overflights of the Soviet Union. The A-12 programme was cancelled as a result of vulnerability concerns, and to make way for its successor: the SR-71 Blackbird.