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.
What is also amazing is that the extremely complex and precise SR-71 was designed without the aid of a computer, and instead was the last aircraft designed with a slide rule!
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.
October 4, 2022 at 9:54 am
Born and raised in the high desert of California and I would see the SR-71 on a daily basis. A day never passed without hearing a boom from either it or something else breaking the sound barrier.
October 4, 2022 at 9:40 pm
An funny detail was that the titanium… they were buying it from the Soviets! Every time the SR-71 spied across the USSR border, the aircraft material was returned to its homeland.
I once read (and I didn’t save the article), that by accident an SR-71 entered the USSR and was run from north to south, but they could never shoot it down, until it made it out of the country.
Some say that the MiG-25 caused the SR-71 to be abandoned. In reality, the cause was the spy satellites, which were more efficient, the pilots were not at risk and they did not generate diplomatic conflicts.
I can imagine how many Tumansky R-15B-300 engines were burned following the Black Bird. The MiG-25 engines continued the tradition of the Nazi Me-262 engines: they did not last at all.