- Education and Science
The SR-71 Blackbird the World's First Mach 3.5 Stealth Plane
The Hammers of Hell
The SR-71 Blackbird was the only aircraft ever to have the distinction of being the fastest operational aircraft in the world from the day it entered service until it was retired three decades later. The Blackbird was capable of flying at speeds greater than Mach 3 at the top 1% of the earth's atmosphere. CIA Director Richard Helms was so taken by a night- time launch of the Blackbird that he would call this famous spy plane " The Hammers of Hell." President Lyndon Johnston would play a vital role in revealing the Blackbird to the world at a press conference on February 29,1964. He stated that the United States had developed an experimental jet aircraft, which flew at a sustained speed of Mach 3 (2,200mph), and at altitudes in excess of 70,000 feet. Pilots of the SR-71 Blackbird were required to wear pressurized suits because the spy plane flew on the edge of space, where the environment was so harsh that if they were exposed it would cause their blood to boil causing death almost instantaneously. On some missions pilots would see the sun rise and set as many as three times, because the Blackbird flew faster than the earth's rotation. This amazing plane was literally faster than a speeding bullet. One Blackbird pilot would remark about the plane's performance on a reconnaissance mission by paraphrasing Psalm 23, "though I fly through the valley of Death, I shall fear no evil for I am at 90,000 feet and climbing." The Blackbird's speed and countermeasures, enabled it to out run and out climb any surface-to-air missile used against it. No Blackbird was ever shot down during its entire thirty years of operational life, no plane in aviation history can make this claim.
The SR-71 Blackbird in Flight
The Blackbird's Engines
The Blackbird was designed by the genius of Lockheed Skunk Works, Kelly Johnston, it was built in complete secrecy at their plant in Burbank California. The J58 turbo-ramjets on the Blackbird were revolutionary in theory, basically it combined the functionality of a turbojet and a ramjet. Below Mach 2, air is sucked into the J-58's front inlets, slowed down and then compressed by a turbine-driven multistage compressor. Then the air is mixed with fuel in the burners, and with more fuel added it would reach the afterburner stage. At speeds greater than Mach 2.2, six bypass tubes opened to feed more air directly from the engine to the afterburner, giving the engine greater fuel efficiency at extreme speeds.
The SR-71 During Air Refueling
The World's First Stealth Airplane
In order to remain a stealth aircraft Lockheed engineers needed to find a way to hide the exhaust that flowed out of the Blackbirds massive J58 turbo-ramjets. Like everything else on the Blackbird the answer was something new and futuristic. By mixing the chemical compound cesium in the Blackbird's fuel it would cause the airplanes exhaust to ionize making it invisible to radar. This complicated ionization process still remains a key component of stealth and is still classified today. The Blackbird's technology though built in the 1960s is still leading edge in the twenty-first century.
The Blackbird was a flying fuel tank, its tanks held over eleven thousand gallons of fuel. For long range missions the Blackbird would require air refueling. The Blackbird's fuel had requirements unlike any other airplane. During air refueling the Blackbird would be forced to lower altitudes and lower airspeeds. The temperature of the airplane's fuel would drop to -90 degrees Fahrenheit flying at speeds less than Mach 2, cruising at Mach 3, it would heat up to 285 degrees Fahrenheit, a temperature at which most fuels boil and explode. To allow for such great temperature fluctuations, a new fuel was designed to maintain such a low vapor pressure that a person couldn't light it with a match.
The SR-71 Blackbird Possibly Over Nevada
The SR-71 in North Vietnam
In May 1967, the Blackbird would be used for the first time for reconnaissance missions over enemy territory in Operation Black Shield, above the skies of North Vietnam. By the end of 1967, Blackbirds would fly twenty missions over North Vietnam and on several occasions they were fired on by SAMs (surface-to-air-missiles). Usually the Blackbird would be out of range before the enemy's radars could lock on to their targets, and if they did fire their missiles the Blackbird would increase its altitude and speed out-running whatever potential threat that existed. In the inky dark blue skies over North Vietnam the SR-71 Blackbird was invincible.
The End of the Blackbird Era
The Blackbird's full potential has never been revealed to the world, but it has long been rumored that it could fly at speeds greater than Mach 3.3 and cruise at altitudes greater than 100,000 feet. The truth is the actual top speed of the SR-71 Blackbird remains a mystery and is still classified. Though the Blackbird was never been seriously threatened by enemy counter-measures, technology and politics would be its ultimate undoing, by the 1980s photo-reconnaissance had improved to the point that satellites would become more cost effective. In October 1997, using a line-item veto, President Bill Clinton stopped the funding for the Blackbird.
In total 2,850 Blackbird flights would be flown out of Area 51 over a period of six years. In the mid-1960s, during the Blackbird's testing, sightings of unidentified flying objects around Area 51 reached unprecedented heights, as the Blackbird flying out from Groom Lake was constantly mistaken for a UFO. Most Blackbird sightings came right after sunset, when the lower atmosphere was at the point of near darkness. With its strange silhouette the Blackbird looked other worldly to airline pilots cruising 6 miles below as the sun reflected off its titanium body. The question now is if there was a replacement for the Blackbird and rumor has it, that its the Aurora and it flies out of Groom Lake too. Only time will tell if the Aurora is a reality, someday the truth will be known.
The SR-91 Aurora
Annie Jacobsen, Area 51 An Uncensored History of America's Top Secret Military Base., Back Bay Books / Little, Brown and Company., Hachette Book Group 237 Park Avenue, New York, NY 10017.
Bill Yenne. Black Jets: A History Of The Aircraft Development At Groom Lake, America's Secret Aviation Base., Zenith Press, A member of Quarto Publishing Group USA Inc., 400 First Avenue North, Suite 400 Minneapolis, MN 55401 USA.