Tools of War: The SR-71 Blackbird
/For over twenty years during the Cold War, the Lockheed SR-71 Blackbird was the world’s fastest and highest-flying reconnaissance aircraft. Utilizing technology that was far ahead of its time, the SR-71 provided vital strategic reconnaissance to American military leaders.
By Seth Marshall
On May 1, 1960, a Lockheed U-2 spyplane flown by Gary Powers was shot down by Soviet SA-2 surface-to-air missiles, touching off an international incident between the US and the Soviet Union. Despite the fact that the U-2 had been flying at over 70,000 feet, it was still vulnerable to interception by the new SAMs that were being built by the Soviet Union. Immediately after Powers’ shootdown, plans were set in motion for the development of a replacement for the U-2 . The result would eventually be the Lockheed SR-71 Blackbird, a plane which was seemingly years ahead of its time.
The Blackbird had its origins in an aircraft known as the A-12, another reconnaissance aircraft that was visually similar to the Blackbird. The A-12 first flew on April 30 1962, and was designed from the outset to fly reconnaissance missions at very high altitudes and cruise at Mach 3+ speeds. While many fighters have been able to approach such speeds at afterburner, none were able to cruise at that speed for long before destroying their engines. In addition, their airframes were not built to withstand the heat caused by the friction of passing air. In order to combat the heat, the Blackbird was built with titanium alloy, which wascapable of taking the 1,000+ degrees Farenheit.[1] Later, it was discovered that the titanium was a very sensitive material which could easily be damaged by conventional tools. As a result, all tools used to maintain the aircraft had to be cadmium-free and made of titanium. Additionally, all SR-71s would be painted matte black, since black paint both emits and absorbs heat, which would further assist the aircraft in surviving the extreme environment that it would be flying in.
An A-12 takes off during flight testing from Groom Lake, also known as Area 51
An A-12 in flight.
Two A-12s were modified to become M-12s, motherships that launched the M-21, an early intelligence-gathering drone. After numerous flights, there was a collision between a drone and mothership, which resulted in the death of a crew member, The program was cancelled in 1966.
An additional development of the A-12 was the F-12, an interceptor variation. With the same basic airframe as the A-12 and the SR-71, the F-12 was equipped with an internal ordinance bay which would carry three Hughes AIM-47A air-to-air radar-guided missiles. The F-12 program was revealed to the public in February 1964 by President Johnson. While it was estimated that 93 F-12s would be necessary for the air defense mission. However, before the aircraft could go into production, the project was cancelled in 1968.[2]
An F-12, a variant of the A-12.
The SR-71, which was a advanced version of the A-12 that had been enlarged and fitted with a back seat for a Reconnaissance Systems Officer. The SR-71 was also capable of carrying more fuel than the A-12. In addition to the materials and paint used in the aircraft, the Blackbird was designed with a shape that would give it a minimal radar cross-section- an early example of a stealthy aircraft. Despite the aircraft being over 100 feet long, engineers succeeded in giving the Blackbird a radar cross-section no larger than a man. After extensive secretive testing in Nevada, the Blackbird was ready for service. A fly-off was conducted between the A-12 and the SR-71 in November 1967 to determine which aircraft would perform the reconnaissance role, but the SR-71 was chosen. The A-12 performed several operational and combat missions over Vietnam, however, it was retired in May 1968 and all remaining A-12s were placed in storage.
The SR-71 Blackbird production line at Lockheed's Skunk Works factory.
A production SR-71A
When it was put into service, the SR-71 was capable of flying at altitudes over 85,000 feet at a speed of Mach 3.2, though it is possible the aircraft can exceed these figures.[3] Based from Beale AFB, CA and Kadena AB, Okinawa (and later RAF Mildenhall, UK), the Blackbird quickly began breaking both speed and altitude records soon after it began operational missions. On September 1, 1974, a Blackbird flew from New York to London in 1 hour, 54 minutes and 56.4 seconds. A few weeks later on September 13, 1974, an SR-71A set an average speed record from London to Los Angeles with an average speed of 1,435.587mph. On July 28, 1976 an SR-71 set an Altitude in Horizontal Flight record of 85,068.997 feet. That same day, it set a Speed Over a Closed Course record of 2,193.167mph. [4]
While the official name of the SR-71 was the Blackbird, many pilots and crew members referred to the aircraft as the Habu, a venomous snake in Japan.
In order to survive the harsh high-altitude environment, pilots were forced to wear a pressure suit and begin mission preparations hours before taking flight. Additionally, the cockpit could be pressurized and air-conditioned to compensate for the 500+ degrees of temperature caused by the friction of the air passing over the skin of the aircraft.
Throughout its 20+ years of active service, the Blackbird was never successfully intercepted by either anti-aircraft systems or other aircraft. When fired on by SAM systems, the aircraft would accelerate beyond the speed of the missile. The only other aircraft that were capable of matching the SR-71 were the American X-15, a rocket-powered experimental aircraft, and the Soviet MiG-25 Foxbat, which could get to Mach 3 but was not capable of remaining at that speed. The SR-71 remains the fastest air-breathing aircraft ever built. Additionally, during the course of its active service career, only one SR-71 was lost- one in April 1989, with both crew recovered. Despite the aircraft’s success at strategic reconnaissance, the Air Force was determined to eliminate the aircraft from its budget. In 1989, the Air Force successfully eliminated the SR-71 from its budget for the following year. In March, the Blackbird was retired- it made its final flight in April 1990, when an aircraft made a record flight from Los Angeles to Washington, D.C., where the aircraft would be placed on display. However, as it happened, the Blackbird was not done flying. NASA received two aircraft in 1991 to use for high-speed research flights, and would continue to do so until 1999. Additionally, the DoD determined that modern satellites, which the Air Force had reasoned would replace the Blackbird, had not completely filled a gap in intelligence gathering. In 1994, Congress provided funding for three aircraft to be returned to flying status. From 1995 until 1998, SR-71s would continue to fly reconnaissance missions. The final SR-71 flight was made on October 9, 1999.
Sources:
1. http://www.nasa.gov/centers/armstrong/news/FactSheets/FS-030-DFRC.html
2. http://airandspace.si.edu/collections/artifact.cfm?object=nasm_A19920072000
3. http://www.lockheedmartin.com/us/100years/stories/blackbird.html
4. http://www.sr-71.org/blackbird/sr-71/
[1] http://www.lockheedmartin.com/us/100years/stories/blackbird.html
[2] http://www.sr-71.org/blackbird/yf-12/
[3] http://www.sr-71.org/blackbird/sr-71/
[4] http://www.sr-71.org/blackbird/sr-71/