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Fly High and Fast – Vol. I: Chapter 7 – SR-71 Blackbird

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JJ Meehan
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The Meehan Family

The Lockheed SR-71 is an advanced, long range, Mach 3+ strategic reconnaissance aircraft developed from the Lockheed A-12 and YF-12A aircraft by the Lockheed Skunk Works as a Black project. The SR-71 was unofficially named the Blackbird, and called the Habu by its crews, referring to an Okinawan species of pit viper. Clarence “Kelly” Johnson was responsible for many of the design’s innovative concepts. A defensive feature of the aircraft was its high speed and operating altitude, whereby, if a surface-to-air missile launch were detected, standard evasive action was simply to accelerate. The SR-71 line was in service from 1964 to 1998, with 12 of the 32 aircraft being destroyed in accidents, though none were lost to enemy action. Since 1976, it has held the world record for the fastest air breathing manned aircraft, a record previously held by the YF-12.

Development

Predecessors

The A-12 OXCART, designed for the CIA by Clarence Johnson at the Lockheed Skunk Works, was the precursor of the SR-71. Lockheed used the name “Archangel” for this design, but many documents use Johnson’s preferred name for the aircraft, “the Article”. As the design evolved, the internal Lockheed designation progressed from A-1 to A-12 as configuration changes occurred, such as substantial design changes to reduce the radar cross-section.

The first flight, by an A-12 known as “Article 121”, took place at Groom Lake (Area 51), Nevada, on 25 April 1962 equipped with the less powerful Pratt & Whitney J75 engines due to protracted development of the intended Pratt & Whitney J58. The J58s were retrofitted as they became available, and became the standard power plant for all subsequent aircraft in the series (A-12, YF-12, M-21) as well as the follow-on SR-71 aircraft.

Eighteen A-12 family aircraft were built. One was a pilot trainer with a raised second cockpit for an Instructor-Pilot and 12 were reconnaissance A-12s to be flown operationally by CIA pilots. Three were YF-12A prototypes of the planned F-12B interceptor version, and two were the M-21 variant.

SR-71

The A-12 OXCART, designed for the CIA by Clarence Johnson at the Lockheed Skunk Works, was the precursor of the SR-71. Lockheed used the name “Archangel” for this design, but many documents use Johnson’s preferred name for the aircraft, “the Article”. As the design evolved, the internal Lockheed designation progressed from A-1 to A-12 as configuration changes occurred, such as substantial design changes to reduce the radar cross-section.

The first flight, by an A-12 known as “Article 121”, took place at Groom Lake (Area 51), Nevada, on 25 April 1962 equipped with the less powerful Pratt & Whitney J75 engines due to protracted development of the intended Pratt & Whitney J58. The J58s were retrofitted as they became available, and became the standard power plant for all subsequent aircraft in the series (A-12, YF-12, M-21) as well as the follow-on SR-71 aircraft.

Eighteen A-12 family aircraft were built. One was a pilot trainer with a raised second cockpit for an Instructor-Pilot and 12 were reconnaissance A-12s to be flown operationally by CIA pilots. Three were YF-12A prototypes of the planned F-12B interceptor version, and two were the M-21 variant.

Design and operational details

A particularly difficult issue with flight at over Mach 3 is the high temperatures generated. As an aircraft moves through the air at supersonic speed, the air in front of the aircraft is compressed into a supersonic shock wave, and the energy generated by this heats the airframe. To address this problem, high-temperature materials were needed, and the airframe of the SR-71 was substantially made of titanium, obtained from the USSR at the height of the Cold War. Lockheed used many guises to prevent the Soviet government from knowing what the titanium was to be used for. In order to control costs, Lockheed used a more easily-worked alloy of titanium which softened at a lower temperature. Finished aircraft were painted a dark blue (almost black) to increase the emission of internal heat (since fuel was used as a heat sink for avionics cooling) and to act as camouflage against the night sky.[citation needed] The aircraft was designed to minimize its radar cross-section, an early attempt at stealth design. The call sign of the aircraft, “Blackbird”, signifies the resistance of its airframe to visible light and radar

Stealth

The SR-71 was the first operational aircraft designed around a stealthy shape and materials. There were a number of features in the SR-71 that were designed to reduce its radar signature. The first studies in radar stealth technology seemed to indicate that a shape with flattened, tapering sides would avoid reflecting most radar energy toward the radar beams’ place of origin. To this end, the radar engineers suggested adding chines to the design and canting the vertical control surfaces inward. The aircraft also used special radar-absorbing materials which were incorporated into sawtooth shaped sections of the skin of the aircraft, as well as cesium-based fuel additives to reduce the exhaust plumes’ visibility on radar. Despite these efforts, the SR-71 was still easily detected on radar while travelling at speed due to its large exhaust stream and air heated by the body (large thermal gradients in the atmosphere are detectable with radar). The SR-71’s radar cross section (RCS) was much greater than the later F-117’s RCS, which is on the order of a small ball bearing.

The overall effectiveness of these designs is still debated; Ben Rich’s team could show that the radar return was, in fact, reduced, but Kelly Johnson later conceded that Russian radar technology was advancing faster than the “anti-radar” technology Lockheed was using to counter it. The SR-71 made its debut years before Pyotr Ya. Ufimtsev’s ground-breaking research made possible today’s stealth technologies, and, despite Lockheed’s best efforts, the SR-71 was still easy to track by radar and had a huge infrared signature when cruising at Mach 3.2 or more. It was visible on air traffic control radar for hundreds of miles, even when not using its transponder. SR-71s were evidently detected by radar, as missiles were often fired at them.

Although equipped with defensive electronic countermeasures, the SR-71’s greatest protection was its high top speed, which made it almost invulnerable to the attack technologies of the time; over the course of its service life, not one was shot down, despite over 4,000 attempts to do so. All the pilot had to do when a SAM was fired was to accelerate.

Operational History

The first flight of an SR-71 took place on 22 December 1964, at Air Force Plant 42 in Palmdale, California.[45] The first SR-71 to enter service was delivered to the 4200th (later, 9th) Strategic Reconnaissance Wing at Beale Air Force Base, California, in January 1966.[46] The United States Air Force Strategic Air Command had SR-71 Blackbirds in service from 1966 through 1991.

 

SR-71s first arrived at the 9th SRW’s Operating Location (OL-8) at Kadena Airbase, Okinawa on 8 March 1968. These deployments were code named “Glowing Heat”, while the program as a whole was code named “Senior Crown”. Reconnaissance missions over North Vietnam were code named “Giant Scale”.

On 21 March 1968, Major (later General) Jerome F. O’Malley and Major Edward D. Payne flew the first operational SR-71 sortie in SR-71 serial number 61-7976 from Kadena AB, Okinawa. During its career, this aircraft (976) accumulated 2,981 flying hours and flew 942 total sorties (more than any other SR-71), including 257 operational missions, from Beale AFB; Palmdale, California; Kadena Air Base, Okinawa, Japan; and RAF Mildenhall, England. The aircraft was flown to the National Museum of the United States Air Force near Dayton, Ohio in March 1990.

From the beginning of the Blackbird’s reconnaissance missions over enemy territory (North Vietnam, Laos, etc.) in 1968, the SR-71s averaged approximately one sortie a week for nearly two years. By 1970, the SR-71s were averaging two sorties per week, and by 1972, they were flying nearly one sortie every day.

While deployed in Okinawa, the SR-71s and their aircrew members gained the nickname Habu (as did the A-12s preceding them) after a pit viper indigenous to Japan, which the Okinawans thought the plane resembled.

Swedish JA 37 Viggen fighter pilots, using the predictable patterns of SR-71 routine flights over the Baltic Sea, managed to lock their radar on the SR-71 on numerous occasions. Despite heavy jamming from the SR-71, target illumination was maintained by feeding target location from ground-based radars to the fire-control computer in the Viggen. The most common site for the lock-on to occur was the thin stretch of international airspace between Öland and Gotland that the SR-71 used on the return flight.

Operational highlights for the entire Blackbird family (YF-12, A-12, and SR-71) as of about 1990 included:

  • 3,551 Mission Sorties Flown
  • 17,300 Total Sorties Flown
  • 11,008 Mission Flight Hours
  • 53,490 Total Flight Hours
  • 2,752 hours Mach 3 Time (Missions)
  • 11,675 hours Mach 3 Time (Total)

Only one crew member, Jim Zwayer, a Lockheed flight-test reconnaissance and navigation systems specialist, was killed in a flight accident. The rest of the crew members ejected safely or evacuated their aircraft on the ground.

The highly specialized tooling used in manufacturing the SR-71 was ordered to be destroyed in 1968 by then-Secretary of Defense Robert McNamara, per contractual obligations at the end of production.[citation needed] Destroying the tooling killed any chance of there being an F-12B, but also limited the SR-71 force to the 32 completed, the final SR-71 order having to be cancelled when the tooling was destroyed.

Libya

In April 1986, following an attack on American soldiers in a Berlin disco, President Reagan ordered the bombing of Muammar Qaddafi’s terrorist camps in Libya . The SR-71 was order to fly over Libya , and take photographs recording the damage our F-111’s had inflicted.  Qaddafi had established a ‘line of death,’a territorial marking across the Gulf of Sidra , swearing to shoot down any intruder, that crossed the boundary. On the morning of April 15, I rocketed past the line at 2,125 mph.

The SR-71 spy plane, the world’s fastest jet crossed into Libya , and were approaching their final turn over the bleak desert landscape, when the Recon Officer informed the Pilot, that he was receiving missile launch signals. the Pilot  quickly increased their speed, calculating the time it would take for the weapons, most likely SA-2 and SA-4 surface-to-air missiles, capable of Mach 5 – to reach our altitude.  He estimated, that they could beat the rocket-powered missiles to the turn, and stay on course, betting our lives on the plane’s performance.

After several agonizingly long seconds, they made the turn and blasted toward the Mediterranean . ‘You might want to pull it back,’ the Recon Officer suggested. It was then that Pilot noticed he still had the throttles full forward.  The plane was flying a mile every 1.6 seconds, well above our Mach 3.2 limit. It was the fastest they would ever fly. he pulled the throttles to idle, just south of Sicily , but they still overran the refueling tanker, awaiting us over Gibraltar …

Typically they trained for a year, flying out of Beale AFB in California , Kadena Airbase in Okinawa , and RAF Mildenhall in England . On a typical training mission, they would take off near Sacramento, refuel over Nevada, accelerate into Montana, obtain a high Mach speed over Colorado , turn right over New Mexico, speed across the Los Angeles Basin, run up the West Coast, turn right at Seattle , then return to Beale.

Total flight time:- Two Hours and Forty Minutes.

One day, high above Arizona , an SR-71 was monitoring the radio traffic, of all the mortal airplanes below us. First, a Cessna pilot asked the air traffic controllers to check his ground speed. ‘Ninety knots,’ ATC replied. A Bonanza soon made the same request. ‘One-twenty on the ground,’ was the reply.

To  their surprise, a navy F-18 came over the radio, with a ground speed check. I knew exactly what he was doing. Of course, he had a ground speed indicator in his cockpit, but he wanted to let all the bug-smashers in the valley, know what real speed was, ‘Dusty 52, we show you at 620 on the ground,’ ATC responded.

The situation was too ripe.

The pilot heard the click of the navigator’s mike button in the rear seat. In his most innocent voice,  He startled the controller by asking for a ground speed check from 81,000 feet, clearly above controlled airspace. In a cool, professional voice, the controller replied, ‘Aspen 20, I show you at 1,982 knots on the ground.’ We did not hear another transmission on that frequency, all the way to the coast.

You can read our other blogs on flying on our WEB Site – FLY HIGH AND FAST” at http://themeehanfamily.com/blogs/fly.htm.

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Written by jjmeehan13

May 7, 2010 at 3:05 pm

Posted in Flying

One Response

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  1. CLASSIC

    Angela

    May 30, 2010 at 5:37 pm


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