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Lockheed YF-12

High-Altitude, High-Speed Interceptor Aircraft

Lockheed YF-12

High-Altitude, High-Speed Interceptor Aircraft


Just three of the fast Lockheed YF-12A interceptors were completed - though the line found itself with no role to fulfill at its end.
National Flag Graphic
ORIGIN: United States
YEAR: 1963
STATUS: Retired, Out-of-Service
MANUFACTURER(S): Lockheed Martin - USA
OPERATORS: United States

Unless otherwise noted the presented statistics below pertain to the Lockheed YF-12 model. Common measurements, and their respective conversions, are shown when possible.
LENGTH: 101.54 feet (30.95 meters)
WIDTH: 55.61 feet (16.95 meters)
HEIGHT: 18.54 feet (5.65 meters)
WEIGHT (EMPTY): 60,859 pounds (27,605 kilograms)
WEIGHT (MTOW): 140,005 pounds (63,505 kilograms)
ENGINE: 2 x Pratt & Whitney J58 / JTD11D-20A turbojet engines developing 31,500 lb thrust each with afterburner (20,500 lb dry thrust).
SPEED (MAX): 2,274 miles-per-hour (3,660 kilometers-per-hour; 1,976 knots)
RANGE: 2,983 miles (4,800 kilometers; 2,592 nautical miles)
CEILING: 89,895 feet (27,400 meters; 17.03 miles)
RATE-OF-CLIMB: 11,820 feet-per-minute (3,603 meters-per-minute)

3 x Hughes AIM-47A "Falcon" Air-to-Air Missiles (AAMs) held in three internal weapon bays (fourth reserved for fire control equipment).
Graphical image of an air-to-air missile weapon
Graphical image of a short-range air-to-air missile

Series Model Variants
• YF-12A - Preproduction Form; three examples completed.
• F-12B - Proposed operational designation
• YF-12C - Designation used for SR-71 aircraft operated by NASA in testing.


Detailing the development and operational history of the Lockheed YF-12 High-Altitude, High-Speed Interceptor Aircraft.  Entry last updated on 3/15/2019. Authored by Staff Writer. Content ©
With the abandonment of the North American XF-108 "Rapier" high-speed interceptor program for the United States Air Force (USAF) came an opportunity for Lockheed to sell its A-12 design as a possible replacement. The A-12 was developed as a high-altitude reconnaissance aircraft for the Central Intelligence Agency so much work on the product had already been completed when cancellation came to the XF-108. Lockheed was able to interest USAF authorities in a modified version of their high performance plane and this gave rise to the "YF-12A" designation which encompassed three converted A-12s pulled from the A-12 production line (aircraft numbers seven, eight and nine of fifteen).

Unlike the A-12, the YF-12A relied on a crew of two (a pilot and a fire control officer) seated in tandem. Additionally it carried the Hughes AN/ASG-18 Look-Down/Shoot-Down (LDSD) Fire Control Radar (FCR) in its nose and tied to an armament display of 3 x Hughes AIM-47A "Falcon" Air-to-Air Missiles (AAMs). These missiles were held in three internal bays (a forth was reserved for the fire control equipment). The radar fit was the same unit developed for the failed XF-108 product.

The A-12 was an excellent starting point for a Cold War interceptor as it was one of the earlier attempts by the Americans to feature inherent stealth features in its construction make up. A chined body and inward-canted vertical tail fins, along with Radar Absorbent Materials (RAMs), were all features of the airframe - qualities that would later be reproduced in the classic SR-71 spyplane. Radar Cross Section (RCS) reduction was also implemented where possible into the A-12's form. The chines at the nose of the A-12 were removed due to the unique radar installation.

Additionally the A-12 was a high-speed, high-altitude performer which the YF-12A would benefit from immensely. The interceptor form carried 2 x Pratt & Whitney J58/JTD11D-20A afterburning turbojet engines which outputted 20,500 lb thrust on dry and 31,500 lb thrust with rehear. Maximum speed reached Mach 3.35 (2,275 miles per hour) with a range out to 3,000 miles and a service ceiling up to 90,000 feet. Rate-of-climb was measured at 11,820 feet-per-minute.

Its general configuration followed the A-12: a long neck holding the cockpit well-ahead of the body was used. The engines were held outboard of the fuselage in individual tubular nacelles breaking up the flow of the wing mainplanes. Two tail fins were featured, one per nacelle dorsal line. This same configuration would be repeated in the upcoming SR-71 product by Lockheed as well.

YF-12A designated the three converted A-12 models which served in the pre-production role. Its in-service designator was to become F-12B but this was never used as the program was halted before production-quality units could begin construction. YF-12C was a fictitious designation applied to SR-71 testing handled by NASA in an effort to keep the SR-71 program under wraps from public eyes.

First flight of the YF-12A was had on August 7th, 1963 and the product was announced to the public in February of the following year to help keep the A-12 secret. Ninety-three F-12B production units were ordered by the USAF in May of 1965 but the growing American military commitment to the Vietnam War (1955-1975) and mounting budgetary needs elsewhere forced the F-12B procurement to the backburner. As time wore on, the need for this dedicated interceptor ebbed away until there was no viable requirement standing. Thusly the YF-12A was cancelled in January of 1968.

The YF-12As that were completed survived a time longer as research-collecting aircraft for both the USAF and NASA where it ended its days. While one of the three examples was lost to an accident in July of 1971, the remaining two examples have been preserved - one at the National Museum of the USAF in Dayton, Ohio and the other making up a portion of the SR-71C display at the Hill Aerospace Museum in Utah.


Our Data Modules allow for quick visual reference when comparing a single entry against contemporary designs. Areas covered include general ratings, speed assessments, and relative ranges based on distances between major cities.

Image of collection of graph types

Relative Maximum Speed
Hi: 5000mph
Lo: 2500mph
This entry's maximum listed speed (2,274mph).

Graph average of 3750 miles-per-hour.
City-to-City Ranges
Graph showcases the Lockheed YF-12's operational range (on internal fuel) when compared to distances between major cities.
Aviation Era
Pie graph section
Pie graph section
Pie graph section
Pie graph section
Pie graph section
Useful in showcasing the era cross-over of particular aircraft/aerospace designs.
Unit Production (3)
Comm. Market HI*: 44,000 units
Military Market HI**: 36,183 units

  * Commercial Market High belongs to Cessna 172.

  ** Military Market High belongs to Ilyushin Il-2.

Altitude Visualization
Small airplane graphic
Supported Roles
Ground Attack
Aerial Tanker
A2A=Air-to-Air; UAV=Unmanned; CAS=Close Support; ASW=Anti-Submarine; AEW=Airborne Early Warning; MEDEVAC=Medical Evac; EW=Electronic Warfare; SAR=Search-Rescue
Commitments / Honors
Military lapel ribbon for Operation Allied Force
Military lapel ribbon for the Arab-Israeli War
Military lapel ribbon for the Battle of Britain
Military lapel ribbon for the Battle of Midway
Military lapel ribbon for the Berlin Airlift
Military lapel ribbon for the Chaco War
Military lapel ribbon for the Cold War
Military lapel ribbon for the Cuban Missile Crisis
Military lapel ribbon for pioneering aircraft
Military lapel ribbon for the Falklands War
Military lapel ribbon for the French-Indochina War
Military lapel ribbon for the Golden Age of Flight
Military lapel ribbon for the 1991 Gulf War
Military lapel ribbon for the Indo-Pak Wars
Military lapel ribbon for the Iran-Iraq War
Military lapel ribbon for the Korean War
Military lapel ribbon for the 1982 Lebanon War
Military lapel ribbon for the Malayan Emergency
Military lapel ribbon representing modern aircraft
Military lapel ribbon for the attack on Pearl Harbor
Military lapel ribbon for the Six Day War
Military lapel ribbon for the Soviet-Afghan War
Military lapel ribbon for the Spanish Civil War
Military lapel ribbon for the Suez Crisis
Military lapel ribbon for the Vietnam War
Military lapel ribbon for Warsaw Pact of the Cold War-era
Military lapel ribbon for the WASP (WW2)
Military lapel ribbon for the World War 1
Military lapel ribbon for the World War 2
Military lapel ribbon for the Yom Kippur War
Military lapel ribbon for experimental x-plane aircraft
* Ribbons not necessarily indicative of actual historical campaign ribbons. Ribbons are clickable to their respective campaigns/operations.

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