Greeting you on one side of the entrance to the San Diego Air & Space Museum is our Lockheed A-12 Blackbird, which was used by the Central Intelligence Agency (CIA) to fly operational missions over Southeast Asia before it retired in 1969 and came here in 1991. This is the tenth A-12 built, and the A-12 was one of three different versions of the Blackbird, which was secretly developed for the CIA by Lockheed. The Blackbird was a Mach 3 (three times the speed of sound) replacement for the U-2 spy plane, and its first flight was performed in secret in 1962. Because it could fly at such high speeds and it had a relatively flat shape, many people on the ground reported UFO sightings when they were actually looking at a Blackbird!