📸 An SR-71B taking off. NASA continued to operate the SR-71 after the program was scrapped by the Air Force. (Source: NASA)
The SR-71 was a top secret reconnaissance plane that flew throughout the Cold War, serving from its maiden flight in 1964 until its final retirement in 1999. Nicknamed the Blackbird, the plane boasted speeds in excess of Mach 3 (2,300 mph) and heights that took it well into the stratosphere. At these speeds and altitudes it could effortlessly perform its task of aerial reconnaissance against targets in the Soviet Union.
The Blackbird was built for speed and stealth. Setting records as the world's fastest manned aircraft, the SR-71 easily cruised at more than three times the speed of sound, instilling a nearly religious experience in those lucky few who flew the blackbird.
That sense of reverence also extended to those who faced the SR-71 as an enemy aircraft. Viktor Belenko, the Soviet MiG pilot who defected to the west in 1976 wrote, "They taunted and toyed with the MiG-25s sent up to intercept them, scooting up to altitudes we could not reach, and circling leisurely above them or dashing off at speeds we could not match."
The Blackbird program got off the ground in 1957 when the US Central Intelligence Agency commissioned the development of an undetectable aircraft capable of high altitude, high speed reconnaissance. The agency turned to Lockheed's "Skunk Works" operation and aeronautical engineering legend Clarence Leonard "Kelly" Johnson.
📸 Air Force Major Brian Shul piloting a Blackbird. (Source: USAF)
For decades, Johnson helped develop some of the most important aircraft in US Air Force history, including such diverse craft as the P-38 Lightning and the U-2 Spy Plane. The Blackbird would be one of Johnson’s final aircrafts, surpassing all previous engineering efforts and establishing a technology platform that still holds every record it set, even more than 50 years after its maiden flight.
The first official Blackbird test flight occurred on April 30th, 1962. This model, the A-12, was a smaller, single-seat version of what would become the SR-71. The test took place at the secretive Groom Lake, Nevada Air Force base also known as Area-51. The first SR-71 flight would take off less than two years later on December 22, 1964.
In 1991, after the retirement of the SR-71 program, two planes were given to NASA’s Dryden Flight Research Center (now the Armstrong Flight Research Center) in Edwards, California. These planes included a standard SR-71 and the SR-71B, a model built in order to train pilots of the aircraft. These planes would go on to be used for a number of experiments run by NASA until their final retirement in 1999.
The SR-71’s abilities made it an ideal platform for high speed, high altitude research in a variety of fields: aerodynamics, propulsion, thermal materials, atmospheric studies, and sonic boom characterization. During their time at NASA, the planes tested laser light as a way to produce air speed and altitude data, collected information on celestial objects on wavelengths blocked to ground based instruments, and was even used in a study to attempt to minimize the peaks of sonic booms on the ground.
📸 An SR-71 in flight. (Source: USAF)
Though many mission records involving the Blackbird have been declassified, the full extent of the plane's operations is unknown. What is known is that in 35 years not a single SR-71 was lost to hostile actions. For enemy fighters, the aircraft was simply too fast and flew too high. For surface-to-air missiles, the radar signature of the SR-71 was too small to be detected until it was too late to react.
In 1989, despite the continued superiority of the platform, the SR-71 program was slated for retirement. It's generally believed that politics were at the root of the retirement since the SR-71 remained the fastest plane in the sky by a wide margin and its reconnaissance capabilities were still needed.
For nearly a decade, opponents and proponents of the SR-71 wrestled with the issue, reactivating the program in the mid-90s and then permanently retiring the craft in 1998. The final SR-71 mission occurred on October 9th, 1999. During the delivery flight from Los Angeles, the aircraft flew coast to coast in just 67 minutes.
SR-71 Blackbird Fragment
SR-71 Blackbird Fragment
Further Reading
Graham, Richard. The Complete Book of the SR-71 Blackbird: The Illustrated Profile of Every Aircraft, Crew, and Breakthrough of the World's Fastest Stealth Jet. Zenith Press, 2015.
Maglieri, Domenic J., Vera Huckel, and Herbert R. Henderson. "Sonic-boom measurements for SR-71 aircraft operating at Mach numbers to 3.0 and altitudes to 24384 meters." (1972).
Miles, Richard B., et al. "Suppression of sonic boom by dynamic off-body energy addition and shape optimization." AIAA Paper 150.2002 (2002): 33.
Boyer, R. R., and R. D. Briggs. "The use of β titanium alloys in the aerospace industry." Journal of Materials Engineering and Performance 14.6 (2005): 681-685.