The world's fastest airplane was the SR-71 Blackbird. It was developed in the 1960s as a black project by Lockheed's Skunk Works division. American aerospace engineer Clarence "Kelly" Johnson was responsible for many of the SR-71's innovative concepts.[2] Its shape was based on the Lockheed A-12, a pioneer in stealth technology with its reduced radar cross section, but the SR-71 was longer and heavier to carry more fuel and a crew of two in tandem cockpits. The SR-71 was revealed to the public in July 1964 and entered service in the United States Air Force (USAF) in January 1966. It was capable of achieving 2,193 mph. (Mach 3.32). It was so fast that it could outrun missiles. It was only retired as a spy plane because satellites were more efficient. During missions, the SR-71 operated at high speeds and altitudes (Mach 3.2 at 85,000 ft), allowing it to evade or outrace threats. If a surface-to-air missile launch was detected, the standard evasive action was to accelerate and outpace the missile. A total of 32 aircraft were built; 12 were lost in accidents, none to enemy action In 1974, the SR-71 set the record for the quickest flight between London and New York at 1 hour, 54 minutes and 56 seconds. In 1989, the USAF retired the SR-71, largely for political reasons and the fact that satellites were more efficient, although several were briefly reactivated before its second retirement in 1998.
