Tag Archives: Skunk Works

26 April 1962

Lockheed test pilot Louis W. Schalk, Jr. (Lockheed)
Lockheed test pilot Louis W. Schalk, Jr. (Lockheed Martin)

26 April 1962: At a non-existent location in the Mojave Desert of Nevada, Lockheed Chief Test Pilot Louis Wellington (“Lou”) Schalk, Jr., was scheduled to take the first Oxcart for a high-speed taxi test on the specially constructed 8,000-foot (2.44 kilometer) runway. However, he had received secret, specific instructions from designer Kelly Johnson to take the craft, known as “Article 121,” airborne.

Lou Schalk roared down the runway and lifted off. He flew at about 20 feet for two miles. The super-secret aircraft was oscillating badly so he set it down straight ahead on the dry lake bed and disappeared into a cloud of dust and flying sand. Johnson said that it “was horrible to watch.” A few minutes later, the needle nose of Article 121 appeared out of the dust as Schalk taxied back to the runway. It turned out that some equipment had been hooked up backwards. Subsequent flights were made without difficulty.

This was the actual first flight of the Central Intelligence Agency’s Top Secret A-12 reconnaissance aircraft. The “official” first flight would come several days later.

Lockheed A-12 60-6924 lands at Groom Lake, NV, after its first flight, 30 April 1962. (Lockheed)
Lockheed A-12 60-6924 lands at Groom Lake, NV, after its first flight, 30 April 1962. (Lockheed Martin)

Designed as the successor to the Agency’s subsonic U-2 spy plane, the twin-engine  jet was capable of flying more than Mach 3 (over 2,000 miles per hour/3,218.7 kilometers per hour) and higher than 80,000 feet (24,384 meters). Built by Lockheed’s “Skunk Works,” the new airplane wasn’t “state of the art,” it was well beyond the state of the art. New materials were developed. New equipment designed and built. New manufacturing processes were invented.

The A-12, developed under the code name “Oxcart,” was unlike anything anyone had ever seen. The first A-12 was referred to as Article 121. “A” = “Article.” “12-” is for A-12. “-1” is for the first production aircraft. So you get “Article 121.” What could be simpler?

The A-12 was so fast and could fly so high that it was invulnerable to any defense. No missile or aircraft or gun could reach it.

Lockheed A-12 Oxcarts and YF-12As at Groom Lake, Nevada. (Central Intelligence Agency)
Lockheed A-12 Oxcarts and YF-12As at Groom Lake, Nevada. (Central Intelligence Agency)

Thirteen A-12s were built for the CIA.  Two M-21 variants, built to carry the Mach 4 D-21 drone, were also produced. An interceptor version was developed for the Air Force as the YF-12A.

Ninety-three Lockheed F-12B interceptors were ordered though Secretary of Defense Robert S. McNamara  refused to release the funding for production. After three years, the order was cancelled. The Air Force liked the A-12, however, and ordered 32 of the more widely known two-place SR-71A “Blackbird” reconnaissance ships.

Today, Article 121 is on display at the Blackbird Airpark, an annex of the Air Force Flight Test Museum, Edwards Air Force Base, California.

Lockheed A-12 60-6924 at the Blackbird Airpark, Air Force Plant 42, Palmdale, California. (© 2012, Bryan R. Swopes)
Lockheed A-12 60-6924 at the Blackbird Airpark, Air Force Plant 42, Palmdale, California. (© 2012, Bryan R. Swopes)

© 2016, Bryan R. Swopes

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29 February 1964

Lockheed YF-12A 60-6934, the first of three prototype Mach 3+ interceptors. (U.S. Air Force)
Lockheed YF-12A 60-6934, the first of three prototype Mach 3+ interceptors. (U.S. Air Force)

29 February 1964: President Lyndon B. Johnson publicly revealed the existence of the Top Secret Lockheed YF-12A, a Mach 3+ interceptor designed and built by Clarence L. “Kelly” Johnson’s “Skunk Works.” President Johnson referred to the interceptor as the “A-11.”

Clarence L. (“Kelly”) Johnson, Director of Lockheed’s Advanced Development Projects (“the Skunk Works”) with the first YF-12A interceptor, 60-6934. (Lockheed Martin)

Intended as a replacement for Convair’s F-106 Delta Dart, three pre-production YF-12As were built for testing. On 1 May 1965, a YF-12A set a speed record of 2,070.103 miles per hour (3,331.507 kilometers per hour) and reached an altitude of 80,259 ft (24,463 meters).

The reason for President Johnson’s announcement of the existence of the YF-12A prototypes was to conceal the existence of the Central Intelligence Agency’s fleet of Lockheed A-12 Oxcart reconnaissance aircraft based at Groom Lake, Nevada. Any sightings of these aircraft could be attributed to test flights of the YF-12As based at Edwards Air Force Base, 160 miles (258 kilometers) to the southwest.

Lockheed A-12 Oxcarts and YF-12As at Groom Lake, Nevada. (Central Intelligence Agency)
Lockheed A-12 Oxcarts and YF-12As at Groom Lake, Nevada. (Central Intelligence Agency)

The YF-12A interceptor is very similar to its A-12 Oxcart and SR-71A Blackbird stablemates. It a large twin-engine delta wing aircraft, flown by a pilot and weapons system operator. Because of the altitudes that the F-12 operates, the crew wears S901F full-pressure suits produced by the David Clark Company. The A-12 is 101.6 feet (30.97 meters) long with a wingspan of 55.62 feet (16.953 meters) and overall height of 18.45 feet (5.624 meters). It has a zero fuel weight of 54,600 pounds (24,766 kilograms) and a maximum ramp weight of 124,600 pounds (56,518 kilograms). ¹

Lockheed YF-12A three-view illustration. (NASA)

The YF-12A is powered by two Pratt & Whitney J58 (JT11D-20A) engines. These are single rotor bleed-bypass turbojets with a 9-stage compressor section and 2-stage turbine. They have a static thrust rating of 31,500 pounds (140.118 kilonewtons), each, at Sea Level with afterburning. The J58s use a unique JP-7 fuel.

Pratt & Whitney J58 test. (Central Intelligence Agency)
Pratt & Whitney J58 test. (Central Intelligence Agency)

The YF-12A has a maximum speed of Mach 3.35 (2,232 miles per hour/3,342 kilometers per hour) at 80,000 feet (24,384 meters). The A-12 has a normal operating cruise speed of Mach 3.1. Its maximum operating altitude is 85,000 feet (25,908 meters) and it has a range of 3,000 miles (4,828 kilometers). Unlike most fighters, the A-12 has a maximum load factor of 2.5 gs. Its maximum bank angle when above Mach 2.5 is 30°.

The United States Air Force ordered 93 production F-12B aircraft, which would have been armed with three Hughes AIM-47A Falcon air-to-air missiles in enclosed bays in the bottom of the fuselage. However, Secretary of Defense Robert S. McNamara refused to release the funds for the purchase for three consecutive years and eventually the project was cancelled.

AIM-47A missile ready for loading into the weapons bay of a Lockheed YF-12A. (U.S. Air Force)
Hughes AIM-47A guided missile ready for loading into the weapons bay of a Lockheed YF-12A. (U.S. Air Force)

The first YF-12A, 60-6934, seen in the top photograph, was extensively damaged by a brake system fire on landing at Edwards AFB, 14 August 1966. It was salvaged and rebuilt as SR-71C 61-7981. The third YF-12A, shown in the photograph below, was lost due to an inflight fire 24 June 1971. The crew safely ejected.

The only existing YF-12A, 60-6935, is in the collection of the National Museum of the United States Air Force at Wright-Patterson Air Force Base, Ohio.

Lockheed YF-12A 60-6936, holder of three World Absolute Speed Records and the World Absolute Altitude Record. (U.S. Air Force)
Lockheed YF-12A 60-6936, holder of three World Absolute Speed Records and the World Absolute Altitude Record, at Edwards Air Force Base, California. (U.S. Air Force)

¹ The Lockheed SR-71A has a length of 107.4 feet (32.74 meters). Wingspan and height are the same. Its zero fuel weight varied from 56,500–60,000+ pounds (25,628–27,216+ kilograms) and the gross weight had a range of approximately 135,000–140,000+ pounds (61,235–63,503+ kilograms).

© 2021, Bryan R. Swopes

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