More than 40 years ago, the Central Intelligence Agency completed flight-testing the A-12, the fastest and highest-flying jet aircraft yet built. On its final validation flight on Nov. 20, 1965, the A-12 flew for 74 minutes at 90,000 feet at a sustained speed of Mach 3.2 and a peak speed of Mach 3.29. Two days later, Kelly Johnson, the aircraft's designer, wrote, "The time has come when the bird should leave its nest."

An Early A-12 Test Flight

The CIA embarked on the A-12 program (code-named OXCART) to provide a successor to the U-2, its first high-altitude strategic reconnaissance aircraft. The U-2 was built to fly deep inside the Soviet Union but was soon vulnerable to Soviet air defenses -- a problem demonstrated on May 1, 1960. On that day, Francis Gary Powers's craft was downed by a surface-to-air missile over Severdlovsk. By then, however, work on the U-2's projected replacement was already underway.

The previous summer, Lockheed Corporation's advanced design facility, nicknamed the "Skunk Works," submitted a design for a new reconnaissance aircraft. The legendary chief designer, Clarence T. "Kelly" Johnson, also designed the U-2. The design was approved in January 1960. Work began on the first prototype the following month. Two years later, the first airframe was ready for flight tests.

The A-12 was designed to defeat Soviet air defenses by flying so high and so fast that it would be invulnerable to interception. Meeting the desired performance characteristics required innovative methods, materials, and engine technologies. Just designing an aircraft able to withstand the heat generated at Mach 3 was a significant challenge. Because all joints and seals had to function while expanded under extremely high temperatures, the aircraft’s fuel tanks leaked while it was on the ground. The engine intakes had to slow down the air entering the huge J-58 turbojets, or the shock wave generated by the aircraft's own speed would cause a flame-out. The A-12 was built almost entirely of titanium. Its graceful curvilinear shape was intended to reduce its radar cross-section. Finally, the A-12 was fitted with a large, complicated, and highly sophisticated camera system. Johnson noted that the aircraft was 12 times more difficult to design than anything Lockheed previously had done. "This matches the design number (A-12) and is obviously right," he added.

Ironically, the A-12 was never used in its intended role. Even as the first airframe was being built, it became obvious that Soviet air-defenses had advanced to the point where even an aircraft flying faster than a rifle bullet at the edge of space would be vulnerable. By 1965, moreover, the photoreconnaissance satellite programs administered by the then-secret National Reconnaissance Office had progressed to the point where manned flights over the Soviet Union to be unnecessary. The A-12 thus saw its first operational deployment in East Asia, flying a total of 29 missions over North Vietnam, Cambodia, Laos, and North Korea between May 1967 and May 1968.

Although the war in Vietnam had earned the OXCART program a reprieve, its end soon arrived. Denied access to the Soviet Union -- its highest-profile target area -- the A-12 was canceled by the Johnson Administration in favor of the Air Force's SR-71 -- itself a variant of Johnson's design. The SR-71 was slightly larger than the A-12 and built as a two-seat aircraft. It did not fly as fast or as high as the A-12 and used a smaller, less effective camera system, but it carried other sensors that the A-12 could not. With the Intelligence Community relying more on satellites for strategic intelligence, two expensive supersonic reconnaissance programs -- parallel and so similar -- could not be justified.

The CIA's nine remaining A-12's were deactivated and placed in storage, where they remained for many years. Eight are on display at museums around the United States. One A-12 is now on the CIA’s Headquarters compound.