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Lockheed YF-12

Lockheed (Skunk Works) · SIGINT / Reconnaissance · USA · Early Jet (1946–1969)

Lockheed YF-12 — SIGINT / Reconnaissance
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The Lockheed YF-12 was an interceptor prototype derivative of the A-12 Oxcart, designed in the early 1960s to replace the F-106 Delta Dart in the continental air-defence role. Three YF-12As were built and flew between 1963 and 1979, demonstrating that a Mach-3 long-range air-to-air interceptor was technically achievable. Although the type set absolute world records for speed (2,070 mph) and altitude (80,257 ft) in May 1965 — records that stood for over a decade — Defense Secretary Robert McNamara cancelled the production F-12B programme in 1968 in favour of investing the budget in surface-to-air missiles and the SR-71 strategic reconnaissance role.

The YF-12 carried the unique Hughes AN/ASG-18 fire control system — the first pulse-Doppler radar fitted to a US fighter — and three Hughes AIM-47 Falcon missiles in internal weapons bays adapted from the A-12's camera bays. Both the radar and the missile were so advanced that their technology was eventually carried over (after considerable redesign) into the F-14 Tomcat's AN/AWG-9 / AIM-54 Phoenix combination, which became the US Navy's long-range fleet air defence weapon for decades. The YF-12 was therefore a kind of unintentional rapid-prototyping platform for the Tomcat's missile-and-radar concept.

Two of the three YF-12As were lost — one in a 1966 hydraulic fire and one to a 1971 in-flight fire over the Pacific. The surviving aircraft (60-6935) flew with NASA from 1969 to 1979 as a research platform supporting hypersonic propulsion and aerodynamic studies, and is now preserved at the National Museum of the United States Air Force in Dayton, Ohio.

For Kids — a shorter, friendlier version

The Lockheed YF-12 was a super-fast jet plane built in the early 1960s. It was designed to protect the skies over America. Only three of these amazing jets were ever built.

The YF-12 could fly faster than three times the speed of sound. That means it was faster than a rifle bullet! It set world records in May 1965 for both speed and how high it could fly. Those records stood for more than ten years.

The jet carried a special radar system inside it. This radar was the first of its kind on an American fighter plane. It also carried missiles tucked away inside hidden bays. The whole setup was so clever that later jets copied the same idea.

The technology from the YF-12 was later used on the F-14 Tomcat. The F-14 became a top fighter jet for the American Navy for many years. So the YF-12 helped make future jets much better, even though it never went into full production.

Fun Facts

  • The YF-12 could fly at over 2,000 miles per hour — faster than a rifle bullet!
  • It flew higher than 80,000 feet, which is more than 15 miles above the ground.
  • Only three YF-12 jets were ever built and tested.
  • The YF-12 was larger than most fighter jets of its time, nearly as long as a city bus.
  • Its speed and altitude world records from 1965 lasted for over a decade.
  • The jet hid its missiles inside special bays, so you could not see them from outside.
  • Its smart radar technology was later used on the famous F-14 Tomcat fighter jet.
  • The YF-12 program was cancelled in 1968 before any extra jets could be made.

Kids’ Questions

How fast could the YF-12 fly?

The YF-12 could reach over 2,000 miles per hour. That is faster than three times the speed of sound. It set a world speed record in May 1965 that lasted for more than ten years.

What made the YF-12's radar so special?

The YF-12 had a radar called the Hughes AN/ASG-18. It was the very first radar of its kind on an American fighter jet. This technology was later improved and used on the F-14 Tomcat.

Why was the YF-12 programme stopped?

The government decided not to build more YF-12 jets in 1968. They chose to spend the money on other things instead. Only the three jets that were already built kept flying until 1979.

Where did the YF-12 keep its missiles?

The YF-12 kept its missiles hidden inside special bays inside the jet. These bays were changed from camera spaces used on an earlier plane called the A-12. This kept the missiles safe and out of sight during flight.

Variants

YF-12A
Three-aircraft prototype interceptor with Hughes AN/ASG-18 radar and AIM-47 Falcon missiles. Flew 1963–1979.
F-12B (cancelled)
Production interceptor variant proposed in 1964; cancelled in 1968 by Secretary McNamara before production began.

Notable Operators

United States Air Force (1963–1969)
Operated the prototypes for testing and record attempts. Set absolute world speed and altitude records on 1 May 1965.
NASA (1969–1979)
Operated the surviving YF-12A from Dryden Flight Research Center as a high-altitude, high-speed aerodynamics and propulsion research platform.

Frequently Asked Questions

What was the YF-12 designed for?

The YF-12 was designed to intercept high-speed, high-altitude Soviet bombers. Its Mach-3 cruise and long-range AIM-47 missiles would have given Air Defense Command a much wider engagement envelope than the F-106 Delta Dart.

Why was the F-12B cancelled?

Secretary of Defense Robert McNamara cancelled production in 1968, judging that surface-to-air missiles and the existing F-106/F-101 fleet were a more cost-effective solution for continental air defence than a fleet of $15M-each Mach-3 interceptors.

How fast was the YF-12?

The YF-12 set the absolute world speed record of 2,070.101 mph (Mach 3.14) on 1 May 1965, along with the world altitude record of 80,257.65 feet on the same flight. Both records stood until broken by the related SR-71 in 1976.

How is the YF-12 related to the F-14 Tomcat?

The Hughes AN/ASG-18 radar and AIM-47 Falcon missile developed for the YF-12 were later evolved into the AN/AWG-9 radar and AIM-54 Phoenix missile fitted to the US Navy's F-14 Tomcat. The YF-12 essentially served as a research platform for that combination.

How many YF-12s still exist?

Only one of the three YF-12As built survives. Aircraft 60-6935 is on permanent display at the National Museum of the United States Air Force at Wright-Patterson AFB, Ohio. The other two were lost to in-flight fires.

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