Tag Archives: 60-6936

7 August 1963

The first Lockheed YF-12A interceptor, 60-6934, flown by James D. Eastham, lands at Groom Lake, Nevada, after its first flight, 7 August 1963. (U.S. Air Force)
James D. Eastham
James D. Eastham (1918–2016)

7 August 1963: The first Lockheed YF-12A interceptor, 60-6934, took off from a top secret air base at Groom Lake, Nevada, on its first flight. Lockheed test pilot James D. Eastham was at the controls.

Three YF-12A prototypes s were built. They were Mach 3+ interceptors developed from the Central Intelligence Agency “Oxcart” Lockheed A-12 reconnaissance airplane.

The interceptors were equipped with a very effective Hughes fire control system and armed with three Hughes AIM-47 Falcon air-to-air missiles. In 1965 the U.S. Air Force placed an order for 93 F-12B interceptors for the Air Defense Command, but Secretary of Defense Robert McNamara continually refused to release the funds which Congress had appropriated. Eventually the contract was cancelled.

In testing, a YF-12A launched a Falcon missile while flying at Mach 3.2 at 74,000 feet (22,555 meters). It successfully intercepted and destroyed a target drone flying at only 500 feet (152 meters).

Lockheed YF-12A 60-6934 at Groom Lake, Nevada. (Central Intelligence Agency)
Lockheed YF-12A 60-6934 at Groom Lake, Nevada. (Central Intelligence Agency)

On 1 May 1965, YF-12A 60-6936, flown by Colonel Robert L. Stephens and Lieutenant Colonel David Andre, set a world speed record of 2,070.101 miles per hour (3,331.505 kilometers per hour) and a sustained altitude record of 80,257.86 feet (22,677 meters).

Lockheed YF-12A 60-6934 in flight. (U.S. Air Force)
Lockheed YF-12A 60-6934 in flight. (U.S. Air Force)

60-6934 was damaged beyond repair in a runway accident at Edwards Air Force Base, 14 August 1966. Part of the airplane was salvaged and used to construct the only SR-71C, 64-17981, a two-seat trainer. The third YF-12A, 60-6936, was destroyed when the crew ejected during an inflight fire near Edwards AFB, 24 June 1971. The only remaining YF-12A, 60-6935, is in the collection of the National Museum of the United States Air Force, Wright-Patterson AFB, Ohio.

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

© 2017, Bryan R. Swopes

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1 May 1965

Lockheed YF-12A 60-6936, flies test mission near Edwards Air Force Base, Califrnia. (U.S. Air Force)
Lockheed YF-12A 60-6936, flies test mission near Edwards Air Force Base, Califrnia. (U.S. Air Force)

1 May 1965: Lockheed YF-12A 60-6936 established five Fédération Aéronautique Internationale (FAI) World Records for Speed: 3,351.507 kilometers per hour (2,070.102 m.p.h.) over a 15/25 Kilometer Straight Course; 2,644.22 kilometers per hour (1,643.04 miles per hour) over a 500 Kilometer Closed Circuit; and 2,718.01 kilometers per hour (1,688.89 miles per hour) over a 1,000 Kilometer Closed Circuit. On the same day, 6936 set an FAI World Record for Altitude in Horizontal Flight of 24,463 meters (80,259 feet).

The World Record-setting flight crews, from left to right, Captain James P. Cooney, Major Walter F. Daniel, Colonel Robert L. Stephens, Lieutenant Colonel Daniel Andre and Major Neil T. Warner. (U.S. Air Force)
The World Record-setting flight crews, from left to right, Captain James P. Cooney, Major Walter F. Daniel, Colonel Robert L. Stephens, Lieutenant Colonel Daniel Andre and Major Neil T. Warner. (U.S. Air Force)

The YF-12A interceptor prototype was flown by pilots Major Walter F. Daniel and Colonel Robert L. Stephens, with fire control officers Lieutenant Colonel Daniel Andre, Major Neil T. Warner and Captain James P. Cooney. Colonel Stephens and Lieutenant Colonel Andre were awarded the Thompson Trophy for the “J” Division, 1965. Their trophy is in the collection of the National Museum of the United States Air Force.

Lockheed YF-12A 60-6936 during speed record trials. The white cross on the aircraft's belly was to assist timers and observers. (U.S. Air Force)
Lockheed YF-12A 60-6936 taking off from Edwards Air Force Base during the speed record trials, 1 May 1965. The white cross on the aircraft’s belly was to assist timers and observers. (U.S. Air Force)

FAI Record File Num #3972 [Direct Link]
Status: ratified – retired by changes of the sporting code
Region: World
Class: C (Powered Aeroplanes)
Sub-Class: C-1 (Landplanes)
Category: Not applicable
Group: 3 : turbo-jet
Type of record: Speed over a closed circuit of 1 000 km with 1 000 kg payload
Performance: 2 718.01 km/h
Date: 1965-05-01
Course/Location: Edwards AFB, CA (USA)
Claimant Walter F. Daniel (USA)
Aeroplane: Lockheed YF-12A (06936)
Engines: 2 Pratt & Whitney J-58/JTD11D-20A

FAI Record File Num #3973 [Direct Link]
Status: ratified – retired by changes of the sporting code
Region: World
Class: C (Powered Aeroplanes)
Sub-Class: C-1 (Landplanes)
Category: Not applicable
Group: 3 : turbo-jet
Type of record: Speed over a closed circuit of 1 000 km with 2 000 kg payload
Performance: 2 718.01 km/h
Date: 1965-05-01
Course/Location: Edwards AFB, CA (USA)
Claimant Walter F. Daniel (USA)
Aeroplane: Lockheed YF-12A (06936)
Engines: 2 Pratt & Whitney J-58/JTD11D-20A

FAI Record File Num #8534 [Direct Link]
Status: ratified – retired by changes of the sporting code
Region: World
Class: C (Powered Aeroplanes)
Sub-Class: C-1 (Landplanes)
Category: Not applicable
Group: 3 : turbo-jet
Type of record: Altitude in horizontal flight
Performance: 24 463 m
Date: 1965-05-01
Course/Location: Edwards AFB, CA (USA)
Claimant R.L. Stephens (USA)
Aeroplane: Lockheed YF-12A
Engines: 2 Pratt & Whitney J-58/JTD11D-20A

FAI Record File Num #8855 [Direct Link]
Status: ratified – retired by changes of the sporting code
Region: World
Class: C (Powered Aeroplanes)
Sub-Class: C-1 (Landplanes)
Category: Not applicable
Group: 3 : turbo-jet
Type of record: Speed over a closed circuit of 500 km without payload
Performance: 2 644.22 km/h
Date: 1965-05-01
Course/Location: Edwards AFB, CA (USA)
Claimant Walter F. Daniel (USA)
Aeroplane: Lockheed YF-12A
Engines: 2 Pratt & Whitney J-58/JTD11D-20A

FAI Record File Num #8926 [Direct Link]
Status: ratified – retired by changes of the sporting code
Region: World
Class: C (Powered Aeroplanes)
Sub-Class: C-1 (Landplanes)
Category: Not applicable
Group: 3 : turbo-jet
Type of record: Speed over a closed circuit of 1 000 km without payload
Performance: 2 718.006 km/h
Date: 1965-05-01
Course/Location: Edwards AFB, CA (USA)
Claimant Walter F. Daniel (USA)
Aeroplane: Lockheed YF-12A
Engines: 2 Pratt & Whitney J-58/JTD11D-20A

FAI Record File Num #9059 [Direct Link]
Status: ratified – retired by changes of the sporting code
Region: World
Class: C (Powered Aeroplanes)
Sub-Class: C-1 (Landplanes)
Category: Not applicable
Group: 3 : turbo-jet
Type of record: Speed over a straight 15/25 km course
Performance: 3 331.507 km/h
Date: 1965-05-01
Course/Location: Edwards AFB, CA (USA)
Claimant R.L. Stephens (USA)
Aeroplane: Lockheed YF-12A
Engines: 2 Pratt & Whitney J-58/JTD11D-20A

World Speed Record holders and Thompson Trophy winners, Colonel Robert F. Stephens and Lieutenant Colonel Daniel Andre. (U.S. Air force)
World Speed Record holders and Thompson Trophy winners, Colonel Robert L. Stephens and Lieutenant Colonel Daniel Andre. (U.S. Air Force)

60-6936 was one of three Mach 3 YF-12A interceptors designed and built by Kelly Johnson’s “Skunk Works”. It was developed from the CIA’s Top Secret A-12 Oxcart reconnaissance airplane. The YF-12A was briefly known as the A-11, which was a cover story to hide the existence of the A-12. Only three were built. The Air Force ordered 93 F-12B interceptors into production as a replacement for the Convair F-106A Delta Dart, but for three straight years Secretary of Defense Robert S. McNamara refused to release the funds that had been appropriated. In 1968, the F-12B project was cancelled.

On 24 June 1971, 60-6936 suffered an in-flight fire while on approach to Edwards Air Force Base. The crew successfully ejected and the airplane crashed a few miles to the north of EDW. It was totally destroyed.

The only surviving example of a YF-12A, 60-6935, is in the collection of the National Museum of the United States Air Force.

The 1965 Thompson Trophy on display at the National Museum of the United States Air Force. (U.S. Air Force)
The 1965 Thompson Trophy on display at the National Museum of the United States Air Force. (U.S. Air Force)

© 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.”

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).

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 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.

The YF-12A interceptor is very similar to its A-12 Oxcart and SR-71A Blackbird stablemates. It was flown by a pilot and a Weapons System Officer. The airplane is 101 feet, 8 inches (30.988 meters) long with a wingspan of 55 feet, 7 inches (16.942 meters) and overall height of 18 feet, 6 inches (5.639 meters). It has an empty weight of 60,730 pounds (27,547 kilograms) and a maximum takeoff weight of 140,000 pounds (63,503 kilograms).

The YF-12A is powered by two Pratt & Whitney J58 (JT11D-20A) high-bypass turbojets which produce 34,000 pounds of thrust (151,240 Newtons), each, with afterburner, burning 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). Its service ceiling is 90,000 feet (27,432 meters) and it has a range of 3,000 miles (4,828 kilometers).

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)

© 2016, Bryan R. Swopes

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