• A-12 CIA reconnaissance aircraft
• SR-71A USAF reconnaissance aircraft
• D-21 drone
• J57 engine (used on U-2’s)
• J58 engine (used on SR-71’s)
Lockheed U2-D AQUATONE
Characteristics and Performance:
Engine: Pratt & Whitney J57-P-13B
Maximum speed: 500 mph (.8 Mach)
Operating ceiling: 70,000+ ft.
Range: 4,000 nautical miles
Span: 80 ft.
Length: 49 ft. 8 in.
Tail Height: 15 ft. 6 in.
Weight: 15,850 lb. (17,270 lbs. with external fuel tanks)
In 1954, Lockheed’s Advanced Development Projects Division (better known as the “Skunk Works”) began work on a reconnaissance aircraft for the Central Intelligence Agency under the codename AQUATONE, while the Air Force’s Strategic Air Command ordered 29 of the new aircraft, designated U-2, under project DRAGON LADY. Lockheed’s best aircraft designer and chief of the Skunk Works project office, Clarence L. (Kelly) Johnson, designed a jet-propelled aircraft with features adapted from gliders, that could fly higher than any other aircraft of the time (over 70,000 ft), carrying a variety of cameras and sensors, as well as have the long-range (2,000 miles) necessary to penetrate deep into Russia and return. Essentially, Kelly Johnson had designed a jet-propelled glider.
To address the two major design problems – fuel capacity and weight, Kelly Johnson incorporated three unique design changes that no other conventional aircraft had. The first was the tail assembly, which was attached to the main body with three tension bolts, an adaptation from sailplane design to save weight. The second was two separate wing panels, attached to the fuselage sides with tension bolts, again just as in sailplanes. Not having the wing spar pass through the fuselage allowed Johnson to locate the camera behind the pilot’s seat, thus improving the center of gravity (CG) and reducing aircraft weight. And finally, the third improvement to reduce weight was replacing standard landing gear with a “bicycle” landing gear with “training wheels”, referred to as “pogo sticks” or “pogos”, to keep the long wings level during takeoff. The pilot dropped off the pogos immediately after lift off, so that they could be recovered and reused.
The aircraft was named U-2 (“U” for Utility) in July 1955 to mask its reconnaissance mission purpose, the same month as the first aircraft, Article 341, was delivered to Groom Lake. Public press releases stated that U-2’s were intended to perform high altitude weather research. The first U-2 overflight of the Soviet Union, from a base in West Germany, occurred on 4 July 1956. Photographs from subsequent flights showed tiny images of MiG-15s and MiG-17s attempting and failing to intercept the aircraft, proving that the Soviets could not shoot down an operational U-2, even though they could track it on radar.
On May 1st 1960, Francis Gary Powers was shot down by a surface-to-air missile (SAM) when he was well over 1,000 miles into the Soviet territory. This loss of the U-2 aircraft ended the CIA’s program of manned overflights into Russia.
Nevertheless, the U-2 continued to provide invaluable service for the USAF. A U-2 from Edwards AFB provided the first photos of the Russian missiles in Cuba, which triggered the Cuban Missile Crisis in October 1962. The U- 2’s excellent high altitude performance and low operating cost have resulted in the aircraft being modified extensively with bigger wings, bigger engines, and a modem “glass” cockpit with computer screens. The U-2 is still in service with the USAF and NASA today, over 50 years after its maiden flight. More than 80 U-2s were built altogether.
While undergoing repairs from the belly-landing, U2-A #56-6721 was modified to accommodate a second crewman, as well as a suite of equipment to measure infrared emissions from aircraft and missiles, in an effort to provide an early warning of a Soviet nuclear attack. Re-designated as a U-2D, the aircraft was delivered to Edwards AFB in December 1959 and assigned to the Special Projects Branch of the 6512th Test Group, for use in Projects LOW CARD and SMOKEY JOE, in support of Missile Detection and Alarm System satellite development.
In May 1968, it received new instrumentation for a series of 31 test sorties in support of Program 949, the development of a space-borne missile warning system. These tests, involving flights from Hanscom Air Force Base, Massachusetts, and Patrick Air Force Base, Florida, continued through October 1968.
During the 1970s, the U-2D served as a chase plane for COMPASS COPE unmanned aerial vehicles. Students from the Air Force Test Pilot School at Edwards occasionally had opportunities to fly the aircraft as part of their studies.
The U-2D s/n 6721 retired in 1980 and was put on display at the March Field Museum in Riverside, California, until 1996. It then returned to Lockheed Martin’s facility at Air Force Plant 42 for restoration and was placed on display at the Palmdale Blackbird Airpark in November 2001, where it remains to this day. U-2 #56-6721 is the last surviving U-2D model, and it never received a J75 engine upgrade unlike the majority of upgraded U-2s.
1. 1956 – One of 29 U-2As built-in Oildale, California
2. 1957 – Assigned to the 4080th Strategic Reconnaissance Wing at Laughlin Air Force Base, Del Rio, Texas
3. 1959 – Damaged during “Miracle at Cortez”, when Taiwanese pilot Maj. Mike Hua managed a dead stick landing at Cortez, Colorado, after his engine flamed out at 70,000 ft
4. 1958 – Repaired and modified to a model D, with a second seat and a sensor suite that included a complicated mirror system (MIDAS array) in the fuselage cavity between cockpits, to measure infrared emissions from aircraft and missiles. The rear seat had only a few basic instruments and no flight controls.
5. 1960 – Transferred to the Air Research and Development Center (ARDC) at Edwards AFB, where it became part of a four-aircraft fleet, consisting of:
• U-2D #56-6721/Article 388
• U-2A #56-6701/Article 368
• U-2A #56-6722/Article 389
• U-2D #56-6954/Article 394
6. 1960/1961 – Frequently flown at Patrick AFB to monitor rocket launches from Cape Canaveral
7. 1960/1961 – Visited Hickam AFB to track Discovery/Corona reconnaissance satellite packages after re-entry
8. 1961 – Used IR sensor to monitor X-15 launch
9. 1966 – Became the only remaining U-2D model after the other U-2D # 56-6954 was sent to Van Nuys and converted to a single-seat U-2C model with a J75 engine
10. 1968 – Upgraded with new instrumentation to assist in development of a space-borne missile warning system
11. 1970’s – Served as a chase plane for COMPASS COPE unmanned aerial vehicles
12. 1978 – Retired and transferred to March AFB museum
13. 1996 – Transferred to AFFTC museum at EAFB and positioned at the Lockheed gate at Plant 42
14. 2001 – Restored and moved to the Blackbird Airpark on 12 November
Left Side: Bob Schumacher – Lockheed Test Pilot
• Co-piloted the first flight of the Lockheed Jetstar
• Was taught to fly the U-2 by Tony LeVier
• Flew the first U-2D model, #56-6710/Article 377, on 7 January 1958
• Took off from aircraft carrier USS Kitty Hawk, in a U-2C model, on 5 August 1963. The aircraft was able to take off in 321 feet, without the use of the catapult. Bob made several carrier landing approaches that day
• On 29 February 1964, Bob made the first U-2 landing on the aircraft carrier USS Ranger in a U-2G model, which was equipped with a spoiler and a tail hook.
Right Side: Bob Murphy – Flight Test Supervisor in charge of maintenance crews and pilot training support operations.
The J57 engine was used on the early U-2 variants before some of the U-2’s were upgraded to J75 engines. It was developed by Pratt & Whitney in the early 1950’s, and was the first 10,000 lbf (pound-force) thrust class engine in the United States. Because the J57 was a twin-spool, axial flow configuration, which was a substantial departure from earlier centrifugal-flow designs, the J57 engine won the prestigious Collier Trophy in 1952. A Collier Trophy is awarded annually to those who have made “the greatest achievement in aeronautics or astronautics in America, with respect to improving the performance, efficiency, and safety of air or space vehicles, the value of which has been thoroughly demonstrated by actual use during the preceding year.”
The military turned to the J57 for its fighter squadrons. In May 1953 it was used on a North American F-100 Super Sabre, when it became the first production aircraft to exceed the speed of sound in level flight, a feat accomplished on its maiden flight. The popular Convair F-102 Delta Dart was the next J57-powered aircraft. The Navy’s Chance Vought F8U-1 used its power to set the first official speed record in excess of 1,000 miles per hour. Other aircraft included Lockheed’s U-2 reconnaissance plane, the prototype of Republic’s F-105 Thunderchief fighter-bomber and Northrop’s Snark intercontinental guided missile.
The early U-2 J57 engine had 10,000 pounds of thrust; at 70,000 feet, only 7 percent of the engine’s sea level thrust could be reproduced. In flight, there was less than a ten knot difference between a speed so fast that it would rip the wings off the aircraft and a speed so slow that it would stall the engine.
From 70,000 feet, the U-2 could glide 300 miles without power. The engine for this aircraft was originally the Pratt and Whitney J57-37, a 10,500 lb. thrust unit built for the B-52. A later 11,500 lbf version, known as the -31, was developed specifically for the U-2s. Pratt and Whitney President Jack Horner and Chief Engineer Wright Parkins crammed a normal three-year engine development program into 12 months. The new engine had a 16-stage compressor with 9 stages in the low range, and 7 in the high pressure chamber.
The low-range compressor was driven by a hollow shaft, and turned at a lower speed than the high compressors. The Pratt and Whitney engine operated at full power for the duration of the flight. At sea level this unit gulped nearly 9,000 pounds of fuel per hour.
At 70,000 feet fuel consumption dropped to 700 pounds per hour. At 74,600 feet, the engine would normally quit from oxygen starvation. In early stages of the program as many as six flameouts occurred on a single flight. With the new fuel system and turbine design of the -31 engine, flameouts at high altitudes have ceased to be a critical problem. An improved ignitions system of a J57-31 ensured air restarts at high altitudes. Eventually, most U-2 were upgraded with J75 Pratt & Whitney engines.
The engine displayed next to the U-2D aircraft at the Blackbird Airpark is a J57-13-B model.
Characteristics and Performance:
Crew: 1 (2 for trainer variant)
Length: 101.6 ft.
Wingspan: 55.62 ft.
Height: 18.45 ft.
Empty weight: 54,600 lb.
Loaded weight: 124,600 lb.
Engines: 2 × Pratt & Whitney J58-1 afterburning turbojets
Maximum speed: Mach 3.35 (2,210 mph, 3,560 km/h) at 75,000 ft.
Range: 2,200 nmi (2,500 mi)
Operating ceiling: 95,000 ft.
Lockheed’s A-12 reconnaissance aircraft was developed for the CIA to replace its predecessor, the U-2 spy plane, for clandestine overflights of the Soviet Union and Cuba. The success of the Russians at tracking the U-2 meant that eventually it would be vulnerable to interception. The CIA specified that U-2’s successor was to fly higher (up to 90,000 ft. versus 70,000), faster (over 2,000 mph versus 500), and also not be visible on Soviet radar. The A-12 was produced from 1962 to 1964, and was in operation from 1963 until 1968.
Lockheed’s Kelly Johnson began preliminary design work to satisfy these requirements in the mid-1950’s, and in 1959 was given the contract to build the A-12 (“A” stood for “Archangel”, a reference to its predecessor U-2, which was called “Angel” internally). The single-seat A-12 was the initial entry in what is now known as the Blackbird family, an aircraft that even today is the fastest and highest flying aircraft ever put in mass production. Cruising at speeds of over Mach 3 (Mach 1.0 refers to the speed of sound, about 650-700 mph), the aircraft had sustained skin temperatures of over 600° F. Titanium was used for its construction, as aluminum normally used for aircraft would melt.
The spaceship-like curves of the Blackbird fuselage, as well as high temperature radar absorbent materials (RAM), were designed to reduce the radar cross-section of the aircraft, and enable it to fly above Mach 3 speeds. The first A-12 flew in April 1962.
By the time A-12s became operational, Soviet Union was considered too dangerous to overfly except in an emergency, and an executive order prohibited overflights. And although crews continued to train for the role of overflying Cuba, U-2s continued to be adequate there.
The Director of the CIA decided to deploy some A-12s to Asia. After an extensive flight test program, the A-12 flew over North Korea and North Vietnam, as part of Operation Black Shield. During these overflights, USS Pueblo was found after photographs from the aircraft’s camera were analyzed. USS Pueblo, still held by the North Vietnam as a museum ship, is the only U.S. Navy ship currently being held captive, and officially remains a commissioned vessel of the United States Navy.
A-12s were retired in 1968, due to budget concerns and because the USAF took over the manned strategic reconnaissance program with the twin-seat SR-71s in March 1968. Thirteen A-12s were produced, of which five were lost in crashes. One of the 13 aircraft was a dedicated trainer aircraft with a second seat, located behind the pilot and raised to permit the Instructor Pilot to see forward.
The deployed A-12s, as well as the eight non-deployed aircraft, were all placed in storage at Palmdale’s Plant 42. All surviving aircraft remained there for nearly 20 years, before being sent to different museums around the United States.
The A-12 aircraft s/n 60-6924 (Article 121)(link to new A-12 page) on display at the Blackbird Airpark is the very first A-12 built, serving as the prototype for the Blackbird family.
1. 1960 – Twelve A-12 ordered by CIA on 26 January
2. 1962 – First A-12 (Article 121) built and transported by truck, in pieces, from Burbank to Groom Lake test facility. Originally had a bare titanium finish, rather than black paint
3. 1962 – “Unofficial” first flight, which was a result of an unintended lift-off during a high-speed taxi, flown by Lou Schalk on 25 April with two J75 P&W engines.
4. 1962 – Official first flight flown on 30 April, a year later than planned. A number of senior Air Force officers and CIA executives witnessed the long-awaited event. Flight lasted 59 minutes and reached 30,000 ft
5. 1962 – First supersonic flight flown on 4 May 1962, reaching Mach 1.1 at 40,000 feet, with Lou Schalk at the controls
6. 1964 –Lockheed Test Pilot James Eastham flew Article 121 up to Mach 3.3, its maximum speed, January
7. Accumulated 418.2 flight hours on 322 missions, before its removal from service
8. 1968 – Stored at Lockheed’s facility at Air Force Plant 42, Palmdale, California, on 6 June, along with the other surviving A-12’s
9. 1991 – Placed on permanent display at Blackbird Airpark in September
Crew: 2 (Pilot and Reconnaissance Systems Officer)
Length: 107 ft. 5 in.
Wingspan: 55 ft. 7 in.
Height: 18 ft. 6 in.
Max. takeoff weight: 172,000 lb.
Engines: Pratt & Whitney J58
Maximum speed: Mach 3.32 at 80,000 ft.
Range: 2,900 nmi
Ferry range: 3,200 nmi
Operating ceiling: 85,000 ft.
• Welding the titanium (85% of airframe) with distilled water, as the chlorine present in tap water was corrosive
• Corrugated skin, which could expand vertically and horizontally, so that smooth skin would not split or curl
• Flattened shape to reflect energy away from the radar beams’ place of origin
• Chines for a greatly reduced radar reflection, which lead to unexpected aerodynamic performance improvements such as additional lift, reduced landing speeds, and stall at higher angles of attack
• Pulsating “spikes” at the front of engine air inlets, slowed the air to form a Mach 1 shock wave in front of the engine compressor at airspeeds above Mach 1.6, since engines could not operate properly if incoming air was above subsonic speeds
• A unique hybrid engine, technically a turbojet inside a ramjet
• Astro-Inertial Navigation System – a precision navigation system, which could correct navigation errors with celestial observations, and was previously only used on missiles
• Specialized protective pressurized suits, which withstood temperatures of 450° F during emergency ejections at speeds of up to Mach 3.2
Lockheed Skunk Works Chief Test Pilot, Robert J. “Bob” Gilliland flew the maiden flight on December 22, 1964 from Plant 42 in Palmdale, CA. The first SR-71 flight took place at Air Force Plant 42 in Palmdale, California, on 22 December 1964. The SR-71 reportedly reached a top speed of Mach 3.4 during flight testing, with its most efficient cruise speed being Mach 3.2.
1. 1966 – Assembly started on 14 January, with delivery to the USAF nine months later
2. 1967 – Maiden flight on 8 February, by Lockheed test pilots Bill Weaver and Darryl Greenamyer
3. 1967/1968 – Assigned to the 9th Strategic Reconnaissance Wing at Beale Air Force Base, California
4. 1969 – Ferried to the 9th SRW’s operating location (OL-8) at Kadena Air Base, in Japan, on 27 September
5. 1969 to1971 – Flew 62 training missions and 45 operational sorties over Southeast Asia
6. 1971 – Returned to Beale AFB on 8 June
7. 1987 – Damaged in May, during the RAF Mildenhall Air Fete, when the pilot tried to initiate a climb at too low a speed just as the afterburners kicked in, bending the aircraft at the manufacturing line.
8. 1987 – On June 21, a flight to Site II in Palmdale was made to estimate cost of repairs and the decision was made to retire the aircraft instead
9. Accumulated 1,729.9 flight hours
10. 1991 – Placed on display at Blackbird Airpark in September
Pratt & Whitney J58 Engine (A-12 and SR-71)
Characteristics and Performance:
Type: Bypass turbojet (turbo-ramjet)
Weight: 6,000 lb (est.)
Length: 17 ft. 10 in. (expands up to 3 in. at max alt and temp)
Diameter: 4 ft. 9 in. (expands up to 3 in at max alt and temp)
Combustion Chambers: 8-can annular
Fuel Nozzles: 48 (6 per chamber)
J58 engine was originally developed by Pratt & Whitney for the US Navy’s Martin P6M jet flying boat capable of dash speeds of up to Mach 3, a project that was cancelled after several production aircraft were built. After the Navy abandoned the Martin P6M project, Lockheed and Pratt & Whitney worked together to redesign the enginefor A-12 use.
The J58 was the first engine designed to operate using its afterburner for extended periods of time, and it was the first engine to be flight-qualified at Mach 3 for the Air Force. It was designed to operate at Mach 3+ for extended periods of time, at altitudes above 80,000 ft.
The J58 is housed in large nacelles on each wing. The large “spikes” or cones, at the front of each engine nacelle, slid in and out to slow airflow through the engines from Mach 3 to Mach 0.5 when the aircraft was to fly subsonic. Efficient operation of the engine inlet requires that it delivers the air to the engine at around 0.4 Mach, regardless of what speed the aircraft if flying at. It essentially becomes a ramjet with a majority of the thrust developing from the airflow through a combination of variable geometry supersonic inlets, bypass doors, and ejector flaps.
The J58 engine was made of special metals that withstood temperatures above 600 degrees, which was the requirement for the titanium skin of the A-12 and SR-71 aircraft. The oil tanks and fuel lines were coated with a very thin layer of gold plating, to reduce temperatures.
The engine had to use special low volatility JP-7 fuel, due to the high-temperature environment in which the engine operates, which would detonate normal jet fuel. The fuel flowing into the engine was used as a coolant to cool the engine, hydraulic fluid, oil, triethylborane tank (required to be injected into the engine to ignite it), afterburner nozzle actuator control lines, air conditioning systems, and the parts of the airframe subjected to aerodynamic heating.
Two engines burned 700 pounds of fuel per minute during its cruise speed of 30 miles per minute. Pratt & Whitney J58 engine development.
The Lockheed D-21 is an American supersonic reconnaissance drone. The D-21 was initially designed to be launched from the back of an M-21 carrier aircraft, a variant of the Lockheed A-12 aircraft. The drone had maximum speed in excess of Mach 3.3 (2,200 miles per hour; 3,600 kilometers per hour) at an operational altitude of 90,000 feet (27,000 meters). Development began in October 1962. Originally known by the Lockheed designation Q-12, the drone was intended for reconnaissance deep into enemy airspace.
The D-21 was designed to carry a single high-resolution photographic camera over a preprogrammed path, then release the camera module into the air for retrieval, after which the drone would self-destruct. Following a fatal accident when launched from an M-21, the D-21 was modified to be launched from a Boeing B-52 Stratofortress. Several successful test flights were made, followed by at least four unsuccessful operational D-21 flights over the People’s Republic of China, before the program was canceled in 1971.