Lockheed SR-71 Blackbird

The SR-71 Blackbird is a supersonic reconnaissance aircraft. It was built by Lockheed's "Skunk Works" in the 1960s for the United States Air Force (USAF). In other words, it was a spy plane.

 Design 
The Blackbird was designed to fly at more than Mach 3 – three times the speed of sound. This meant it would become very hot during flight. To help with this, most of the aircraft was made of titanium. Radar absorbing material was also used to make the aircraft more difficult to detect.

SR-71 Blackbird used a special fuel called JP-7. Before the flight, the fuel tanks used to leak. This is because at ground altitude the tolerances (distance between parts of the fuel tank) were larger than at the plane's cruising altitude. Once in the air, because of the speed and air resistance, the parts became very hot. Because of this heat, the distance between the parts shrank stopping the loss of fuel.sr-71.org

The aircraft also had cameras and radars fitted to take photographs of targets.

 History 
The first Blackbird flight happened on December 22, 1964 in Palmdale, California. In January 1966, the first aircraft entered service with the USAF. No aircraft were lost in war but one crashed in an accident in 1969. Only 32 aircraft were built. Its final flight was on March 6, 1990, Blackbird S/N 61-7972. The SR-71 program was retired from service in 1998.

 Records 
The aircraft flew at an altitude of over  and at speeds over . It held the world record for the jet-powered flight, flying at Mach 3.2.  The record was broken in March 2004 by NASA's X-43A aircraft.

Specifications (SR-71A)
350px|right|Orthographically projected diagram of the SR-71A Blackbird.

 Notes 

 References 

Category:United States Air Force aircraft
SR-71