SR71 Blackbird is and add-on for Microsoft Flight Simulator (MS SF) 2004. So to use it you have to have Microsoft Flight Simulator 2004 allready installed. Also you will need 50 MB of free hard drive space. The Lockheed SR-71 "Blackbird" was an advanced, long-range, Mach 3+ strategic reconnaissance aircraft. It was developed as a black project from the Lockheed A-12 reconnaissance aircraft in the 1960s by Lockheed and its Skunk Works division. Clarence "Kelly" Johnson was responsible for many of the design's innovative concepts. During reconnaissance missions, the SR-71 operated at high speeds and altitudes to allow it to outrace threats. If a surface-to-air missile launch was detected, the standard evasive action was simply to accelerate and outfly the missile. The SR-71 served with the U.S. Air Force from 1964 to 1998. A total of 32 aircrafts were built; 12 were lost in accidents, but none lost to enemy action. The SR-71 has been given several nicknames, including Blackbird and Habu. Since 1976, it has held the world record for the fastest air-breathing manned aircraft, a record previously held by the YF-12.