MOCpages : Share your LEGO® creations
LEGO models my own creation MOCpages toys shop Lockheed YF-12A InterceptorHistoric military
Welcome to the world's greatest LEGO fan community!
Explore cool creations, share your own, and have lots of fun together.  ~  It's all free!
Lockheed YF-12A Interceptor
Lockheed YF-12A Interceptor. Model features removable nosecone with radar antenna, detailed dual cockpits with opening canopies, fully functional landing gear, opening inflight refueling receptacle, opening weapons bays, folding ventral fin, and moving flight control surfaces including flaps, ailerons, and ruddervators.
About this creation

Closeup of the Hughes ASG-18 fire control radar of the YF-12A. Used in conjunction with the infrared system the aircraft could identify and track targets at ranges of as far as 300 miles, including low flying aircraft. The open weapons bays were modified from the A-12's reconnaissance bays, with 3 holding AIM-47B Falcon missiles and the fourth containing fire control equipment. The folded central ventral fin can also be seen. Upon gear retraction the fin unfolds to its vertical position, necessitated by the removal of the forward chines of the A-12 in favor of the radome.

The Lockheed YF-12 was an American prototype interceptor aircraft evaluated by the United States Air Force. The YF-12 was twin-seat version of the secret single-seat Lockheed A-12 reconnaissance aircraft, which led to the U.S. Air Force's Lockheed SR-71 Blackbird twin-seat reconnaissance variant. The YF-12 set and held speed and altitude world records of over 2000 mph and over 80,000 ft (later surpassed by the SR-71), and is the world's largest manned interceptor to date.

Design and development

In the late 1950s the United States Air Force (USAF) sought a replacement for its F-106 Delta Dart interceptor. As part of the Long Range Interceptor Experimental (LRI,X) program, the North American XF-108 Rapier, an interceptor with Mach 3 speed, was selected. However, the F-108 program was canceled by the Department of Defense in September 1959. During this time, Lockheed's Skunk Works was developing the A-12 reconnaissance aircraft for the Central Intelligence Agency (CIA) under the Oxcart program. Kelly Johnson, the head of Skunk Works, proposed to build a version of the A-12 named AF-12 by the company; the USAF ordered three AF-12s in mid-1960.

Underside view of the model, showing the YF-12A's ventral fins (added for stability due to the removal of the forward chines) and the open weapons bays.

The AF-12s took the seventh through ninth slots on the A-12 assembly line; these were designated as YF-12A interceptors. The main changes involved modifying the A-12's nose to accommodate the Hughes AN/ASG-18 fire-control radar originally developed for the XF-108, and the addition of the second cockpit for a crew member to operate the fire control radar for the air-to-air missile system. The modifications changed the aircraft's aerodynamics enough to require ventral fins to be mounted under the fuselage and engine nacelles to maintain stability. The four bays previously used to house the A-12's reconnaissance equipment were converted to carry Hughes AIM-47 Falcon (GAR-9) missiles. One bay was used for fire control equipment.

Underside view of the forward fuselage and the four weapons bays. Three AIM-47 Falcon air to air missiles are loaded, with the fourth bay unused. Also visible is the detail in the forward landing gear bay.

The first YF-12A flew on 7 August 1963. President Lyndon B. Johnson announced the existence of the aircraft on 24 February 1964. The YF-12A was announced in part to continue hiding the A-12, its still-secret ancestor; any sightings of CIA/Air Force A-12s based at Area 51 in Nevada could be attributed to the well-publicized Air Force YF-12As based at Edwards Air Force Base in California.

Top view of the model. The chines have been cut back for the addition of the radome housing the Hughes ASG-18 radar antenna. At the front of each chine is the seeker head for the infrared tracking system. The rectangular door on the aircraft's spine aft of the FCO's cockpit is the inflight refueling port.

On 14 May 1965 the Air Force placed a production order for 93 F-12Bs for its Air Defense Command (ADC). However, Secretary of Defense Robert McNamara would not release the funding for three consecutive years due to Vietnam War costs. Updated intelligence placed a lower priority on defense of the continental US, so the F-12B was deemed no longer needed. Then in January 1968, the F-12B program was officially ended.

Closeup of the model's dual cockpits. The forward cockpit housed the pilot, and the rear housed the FCO (Fire Control Officer).

Operational history

Air Force Testing

During flight tests the YF-12As set a speed record of 2,070.101 mph (3,331.505 km/h) and altitude record of 80,257.86 ft (24,462.6 m), both on 1 May 1965,[10] and demonstrated promising results with its unique weapon system. Six successful firings of the AIM-47 missiles were completed. The last one was launched from the YF-12 at Mach 3.2 at an altitude of 74,000 ft (22,677 m) to a JQB-47E target drone 500 ft (152 m) off the ground. One of the Air Force test pilots, Jim Irwin, would go on to become a NASA astronaut and walk on the Moon.

The program was abandoned following the cancellation of the production F-12B, but the YF-12s continued flying for many years with the USAF and with NASA as research aircraft.

NASA Testing

The initial phase of this program included test objectives aimed at answering some questions about implementation of the B-1. Air Force objectives included exploration of its use in a tactical environment, and how AWACS would control supersonic aircraft. The Air Force portion was budgeted at US$4 million. The NASA tests would answer questions such as how engine inlet performance affected airframe and propulsion interaction, boundary layer noise, heat transfer under high Mach conditions, and altitude hold at supersonic speeds. The NASA budget for the 2.5-year program was US$14 million.

Of the three YF-12As, #60-6934 was damaged beyond repair by fire at Edwards during a landing mishap on 14 August 1966; its rear half was salvaged and combined with the front half of a Lockheed static test airframe to create the only SR-71C.

YF-12A #60-6936 was lost on 24 June 1971 due to an in-flight fire caused by a failed fuel line; both pilots ejected safely just north of Edwards AFB. YF-12A #60-06935 is the only surviving YF-12A; it was recalled from storage in 1969 for a joint USAF/NASA investigation of supersonic cruise technology, and then flown to the National Museum of the United States Air Force at Wright-Patterson Air Force Base near Dayton, Ohio on 17 November 1979.

A fourth YF-12 aircraft, the "YF-12C", was actually the second SR-71A (617951). This SR-71A was re-designated as a YF-12C and given a fictitious serial number 60-6937 from an A-12 to maintain SR-71 secrecy. The aircraft was loaned to NASA for propulsion testing after the loss of YF-12A (606936) in 1971. The YF-12C was operated by NASA until September 1978, when it was returned to the Air Force.

General characteristics

Crew: 2
Length: 101 ft 8 in (30.97 m)
Wingspan: 55 ft 7 in (16.95 m)
Height: 18 ft 6 in (5.64 m)
Wing area: 1,795 ft (167 m)
Empty weight: 60,730 lb (27,604 kg)
Loaded weight: 124,000 lb (56,200 kg[6])
Max. takeoff weight: 140,000 lb (63,504 kg)
Powerplant: 2 Pratt & Whitney J58/JTD11D-20A afterburning turbojet with compressor bleed bypass
Dry thrust: 20,500 lbf (91.2 kN) each
Thrust with afterburner: 31,500 lbf (140 kN) each


Maximum speed: Mach 3.35 (2,275 mph, 3,661 km/h[6]) at 80,000 ft (24,400 m)
Range: 3,000 mi (4,800 km)
Service ceiling: 90,000 ft (27,400 m)


Missiles: 3 Hughes AIM-47A air-to-air missiles located internally in fuselage bays


Hughes AN/ASG-18 look-down/shoot-down fire control radar

Info courtesy Wikipedia.


 I like it 
  July 11, 2016
Can I buy this seriously
Justin Davies
 I like it 
Matt Bace
  April 15, 2014
Wow! That is perfect, probably the best YF-12/SR-71 ever done in LEGO. It's too bad that the black color makes it hard to make out some of the details, because it looks like you have put in the effort to get all of them just right.
 I like it 
  April 15, 2014
Great work! Nicely executed and the details are amazing.
 I like it 
  April 15, 2014
incredibly detailed rendition of an equally exceptionally looking bird! Love it!
 I like it 
  April 15, 2014
Amazing work! I was hoping you would make this one. Beautifully detailed. Excellent
 I made it 
  April 15, 2014
Quoting Tyro Cook Excellent rendition. I like how you went to the trouble to reproduce the corrugated look of the skin. I wish I could incorporate this much detail into my aircraft, but I haven't the patience to work at this scale.
I always seem to reach that point somewhere around halfway to 3/4 complete with my models where I have to step back, shake my head and think "what was I thinking???"...Then I calm down, approach the project fresh an hour later and keep banging on. The end result is what you see above. :D I saw your Phantom today, kinda a baby brother to mine. I can see the influences from Mad Physicist and my models in there both. I would suggest moving the chin pod forward, it should end roughly even with the tip of the nose.
 I like it 
  April 15, 2014
 I like it 
  April 15, 2014
Excellent rendition. I like how you went to the trouble to reproduce the corrugated look of the skin. I wish I could incorporate this much detail into my aircraft, but I haven't the patience to work at this scale.
 I like it 
  April 15, 2014
 I like it 
  April 15, 2014
Great job on such a perfect plane!
By Justin Davies
Add to my favorite builders

people like this. See who.

5,545 visitors
Added April 15, 2014
Lockheed SR-71A Blackbird  You are at the end of this folder.
More from Justin
More across MOCpages

LEGO models my own creation MOCpages toys shop Lockheed YF-12A InterceptorHistoric military

You Your home page | LEGO creations | Favorite builders
Activity Activity | Comments | Creations
Explore Explore | Recent | Groups
MOCpages is an unofficial, fan-created website. LEGO® and the brick configuration are property of The LEGO Group, which does not sponsor, own, or endorse this site.
©2002-2018 Sean Kenney Design Inc | Privacy policy | Terms of use