What was the sr 71 blackbird used for

Twin-engine, two-seat, supersonic strategic reconnaissance aircraft; airframe constructed largley of titanium and its alloys; vertical tail fins are constructed of a composite laminated plastic-type material to reduce radar cross-section; Pratt and Whitney J58 JT11DB turbojet engines feature large inlet shock cones. Photographer Eric Long demonstrates how lighting the Blackbird from behind can help highlight the shape and contour of the aircraft.

Because the aircraft was designed to reflect light, using a flash head on will result in a photograph that lacks detail. No reconnaissance aircraft in history has operated globally in more hostile airspace or with such complete impunity than the SR, the world's fastest jet-propelled aircraft. The Blackbird's performance and operational achievements placed it at the pinnacle of aviation technology developments during the Cold War. This Blackbird accrued about 2, hours of flight time during 24 years of active service with the U.

Air Force. On its last flight, March 6, , Lt. Ed Yielding and Lt. At the flight's conclusion, they landed at Washington-Dulles International Airport and turned the airplane over to the Smithsonian. No reconnaissance aircraft in history has operated in more hostile airspace or with such complete impunity than the SR Blackbird. It is the fastest aircraft propelled by air-breathing engines. The airplane was conceived when tensions with communist Eastern Europe reached levels approaching a full-blown crisis in the mids.

Air Force recognized that this relatively slow aircraft was already vulnerable to Soviet interceptors. They also understood that the rapid development of surface-to-air missile systems could put U-2 pilots at grave risk. The danger proved reality when a U-2 was shot down by a surface to air missile over the Soviet Union in Lockheed's first proposal for a new high speed, high altitude, reconnaissance aircraft, to be capable of avoiding interceptors and missiles, centered on a design propelled by liquid hydrogen.

This proved to be impracticable because of considerable fuel consumption. Lockheed then reconfigured the design for conventional fuels. Lockheed's clandestine 'Skunk Works' division headed by the gifted design engineer Clarence L.

To meet these challenging requirements, Lockheed engineers overcame many daunting technical challenges. The design team chose to make the jet's external skin of titanium alloy to which shielded the internal aluminum airframe. Two conventional, but very powerful, afterburning turbine engines propelled this remarkable aircraft. These power plants had to operate across a huge speed envelope in flight, from a takeoff speed of kph mph to more than 3, kph 2, mph.

To prevent supersonic shock waves from moving inside the engine intake causing flameouts, Johnson's team had to design a complex air intake and bypass system for the engines. Skunk Works engineers also optimized the A cross-section design to exhibit a low radar profile.

Lockheed hoped to achieve this by carefully shaping the airframe to reflect as little transmitted radar energy radio waves as possible, and by application of special paint designed to absorb, rather than reflect, those waves.

This treatment became one of the first applications of stealth technology, but it never completely met the design goals. Test pilot Lou Schalk flew the single-seat A on April 24, , after he became airborne accidentally during high-speed taxi trials.

The airplane showed great promise but it needed considerable technical refinement before the CIA could fly the first operational sortie on May 31, - a surveillance flight over North Vietnam. While Lockheed continued to refine the A, the U. Air Force ordered an interceptor version of the aircraft designated the YFA. The Skunk Works, however, proposed a "specific mission" version configured to conduct post-nuclear strike reconnaissance.

Lockheed built fifteen As, including a special two-seat trainer version. Two As were modified to carry a special reconnaissance drone, designated D Titanium skin. Because the aircraft was designed to fly faster than 2, mph, friction with the surrounding atmosphere would heat up the fuselage to a point that would melt a conventional airframe. The plane was therefore made of titanium, a metal that was able to withstand high temperatures while also being lighter than steel.

Using titanium presented other problems, however. First, a whole new set of tools -- also made of titanium -- had to be fabricated, because regular steel ones shattered the brittle titanium on contact.

Second, sourcing the metal itself proved tricky. The US government had to purchase a lot of that, probably using bogus companies," said Merlin. The initial aircraft were flown completely unpainted, showing a silver titanium skin. They were first painted black in , after the realization that black paint -- which efficiently absorbs and emits heat -- would help lower the temperature of the entire airframe. The "Blackbird" was born.

Same plane, different names. The A was soon evolved into a variant that was designed as an interceptor -- a type of fighter aircraft -- rather than a surveillance plane. Effectively, this meant adding air-to-air missiles and a second cockpit, for a crew member to operate the necessary radar equipment. This new plane, which looked identical to the A except for the nose, was called the YF A third variant was produced around this time, called the M, which had a pylon on its back for mounting and launching one of the first unmanned drones.

Two were built, but the program was halted in after a drone collided with its mothership, killing one of the pilots. Project Habbakuk: Britain's secret attempt to build an ice warship.

To minimize its chances of being detected in enemy airspace, the SR incorporated one of the first uses of stealth technology, including radar-absorbing composites for the leading edges and tail fins, and black paint impregnated with ferrite particles that soaked up radar energy.

For the next two decades, the SR would be called upon to photograph sites around the world that were beyond reach of spy satellites. Operating the battery of high-resolution cameras was the job of the reconnaissance systems officer in the back seat, while in the front seat, the pilot had his hands full just flying the airplane.

According to Pappas, one of 86 rigorously selected pilots who flew the Blackbird on missions, a dauntingly demanding aspect of the job was keeping the nose within one or two degrees of the prescribed angle—the only conditions under which the SR was stable.