During its twenty-four-year career, the SR-71 remained the world’s fastest and highest-flying operational aircraft in the world. At 80,000 feet, the Blackbird could survey 100,000 square miles of the ground below per hour. In July, 1976, an SR-71 even set two world records – one was an absolute speed record of 2,193.167 mph while the other was an absolute altitude record of 85,068.997 feet. While other aircraft of the era could in theory reach speeds of 2,000 mph only in short after-burner-driven bursts, the SR-71 needed to maintain the record-setting speed for hours at a time.
The aircraft was noted for being able to fly faster than a standard 30.06 rifle bullet when fired, and at cruise, the Blackbird’s skin temperatures reached about 600 degrees, which actually caused the aircraft to grow three to four inches in length and as much as one to two inches in width. In addition, the exterior of the pilot windows could reach 620 degrees. The designers knew that at such velocity, friction with the atmosphere would generate temperatures that could melt a conventional airframe and as a result, the aircraft received that iconic black paint that could absorb the heat. It gave the plane that unofficial nickname, “Blackbird.”
Additionally, titanium alloy – which provided the strength of steel but was relatively lightweight – was utilized for the airframe. Along with its low weight, titanium was the only material that could provide durability at excessive temperatures. One issue was that the metal could be brittle if mishandled, which meant that even new tools had to be designed and fabricated. Those too were also made from titanium.
BF Goodrich also developed a special power aluminum powder that could be impregnated into the tires to reject the airframe heat.
At 80,000 feet, the pilots could actually see the curvature of the Earth about 360 miles in all directions, while the sky appeared as a deep blue-black because most of the atmosphere, which gives the sky its blue color, is below. Because of the high altitude, pilots wore specially-designed flight suits that were later used in the initial Space Shuttle flights.
A Senior Editor for 1945, Peter Suciu is a Michigan-based writer who has contributed to more than four dozen magazines, newspapers, and websites with over 3,000 published pieces over a twenty-year career in journalism. He regularly writes about military hardware, firearms history, cybersecurity, and international affairs. Peter is also a Contributing Writer for Forbes. You can follow him on Twitter: @PeterSuciu.