|The SR-71B Blackbird, flown by the Dryden Flight Research Center as NASA 831
slices across the snow-covered southern Sierra Nevada Mountains of California
On December 22, 1964, the Lockheed SR-71 Mach 3+ strategic reconnaissance aircraft started for her maidenflight. Since 1976, it has held the world record for the fastest air-breathing manned aircraft.
The SR-71’s predecessor was the reconnaissance aircraft U-2. But it was known to be very slow and was mostly used by CIA. The SR-71 was designed for flight at speeds beyond Mach 3 with a flight crew of two in tandem cockpits and to minimize its radar cross-section. As a special feature, titanium was used on 85% of the Blackbird. This was special, because most aircraft were equipped with the minimum amount of titanium due to the high costs. Also, the aircraft was equipped with several features to reduce its radar signature, but engineers later conceded that the Soviet radar technology advanced faster than the stealth technology employed against it. The sharp edges on either side of the aircraft generated powerful vortices and additional lift, which significantly improved the aerodynamic performance and stability. The SR-71 could be refueled in air by special tankers on longer missions, and refueling even worked at the tanker’s maximum airspeed. The incredible speed that came with the aircraft and its new operational service ceiling of more than 20km, new oxygen masks had to be created to provide more oxygen as well as a heavy-duty cooling system.
What made the SR-71 so innovative were her engines, two Pratt & Whitney J58-P4, which could produce a static thrust of 145 kN. A unique hybrid, the engine can be thought of as a turbojet inside a ramjet. At lower speeds, the turbojet provided most of the compression and most of the energy from fuel combustion. At higher speeds, the turbojet largely ceased to provide thrust; instead, air was compressed by the shock cones and fuel burned in the afterburner. During its maiden flight on December 22, 1964, the SR-71 reached a top speed of Mach 3.4 and the very first aircraft to enter service was delivered to California in 1966. In 1968, the first operating location was reached in Okinawa, where the nickname Habu (a Japanese snake) was created for the aircraft. During the years, a total of 32 planes were built and the SR-71 finally retired in 1998. The SR-71 was the world’s fastest and highest-flying operational manned aircraft throughout its career. The New York City – London distance was flown in only 1 hour 54 minutes, which was an hour faster than the fastest commercial Concorde flight. The Boeing 747 would take about 6 hours and 15 minutes for the same distance. The SR-71 finally was permanently retired in 1998. All remaining aircrafts are on display in museums today, except two which remain at NASA.
At yovisto, you may be interested in a detailed interview with a former Blackbird pilot, who discusses his experiences in the air and talks about myths concerning the aircraft and their missions.
References and Further Reading:
- SR-71 Blackbird photographs and videos at NASA’s Dryden Flight Research Center’s web site
- The Online Blackbird Museum
- The SR-71 Pilot Full Pressure Suit
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