The Lockheed SR-71 Blackbird is, to date, the fastest airplane ever to streak across the sky, even though it's more than 30 years old. Capable of speeds over 2200 miles per hour—that's more than three times the speed of sound—the SR-71 can fly at altitudes above 80,000 feet. What does it feel like to travel at Mach 3, 15 miles above the earth? Pilots report that, with no view out the window, there's an eerie sensation of motionlessness when cruising in the Blackbird.
To fly safely in this harsh, low-pressure environment pilots must wear a full-pressure suit for protection. Even though the temperature outside the aircraft hovers around -70 degrees F, the sheer friction of flying at Mach 3 heats the leading edges of the SR-71 to 800 degrees F. To help withstand this kinetic heat, the Blackbird's airframe is built almost entirely of titanium and is finished in a special heat-emitting black paint, which helps to cool the aircraft and gives it its nickname.
The SR-71 can operate for about an hour at top speed before it needs refueling—a feat that can be accomplished in mid-air with a special tanker aircraft. The Blackbird is powered by two Pratt and Whitney J-58 axial-flow turbojets with afterburners, each producing about 34,000 pounds of thrust. Studies have shown that when the aircraft is cruising at Mach 3 or above only about 25 percent of the total thrust is produced by the engines themselves. The balance is produced by the unique design of the engine inlet and housing, which is equipped with special afterburners.
The two-seat SR-71 was developed in the early 1960s by the U.S. Air Force as a strategic reconnaissance aircraft. The first flight of an SR-71 was in 1964 at a classified location in Nevada. The aircraft's first operational "sortie" was flown out of Okinawa, Japan in 1968. Most of the SR-71 fleet has now been retired, except for two Blackbirds currently on loan to NASA's Dryden Flight Research Center where the aircraft are being used as "test beds" for high altitude research."
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