To survive the extreme heat generated by friction at Mach 3+, the aircraft required radical design solutions:
: Its Pratt & Whitney J58 engines acted as a turbojet-ramjet hybrid, becoming most efficient at speeds above Mach 3. LockheedSR71Blackbird.rar
: Roughly 85% of the airframe was titanium, which could withstand the 600°F (315°C) surface temperatures. To survive the extreme heat generated by friction
: On July 28, 1976, it set absolute records for speed (2,193.167 mph) and altitude (85,068.997 feet). 193.167 mph) and altitude (85