43 Years Ago Today: The SR-71 Blackbird Takes Flight
By James Grahame
The inaugural flight of the SR-71 took place on December 22, 1964, becoming the most impressive Christmas present ever to slip out of Lockheed's Skunk Works facility at Burbank airport. Amazingly, the SR-71 took to the air less than 17 years after Chuck Yeager first broke the sound barrier.
On paper, this titanium-skinned monster was capable of Mach 3.2, although pilot Brian Shul has since admitted that he once pushed a Blackbird to Mach 3.4 in his haste to leave Libyan airspace well in advance of looming surface-to-air missiles. He reported that the aircraft seemed to fly smoother than ever at those unbelievable speeds, cruising at well over 80,000 ft.
Propulsion came from a pair of Pratt & Whitney J58-P4 engines that produced a total of 65,000 lbf of static thrust and operated on afterburner at all times. The Sunkworks team had initially played with the idea of using liquid hydrogen for propulsion, but were unable to figure out how to cram the storage tanks into the airframe. They settled upon a much safer fuel known as Jet Propellant 7, which featured a high flash point of 60 C that reportedly couldn't be lit with a match (convenient, since the SR-71 leaked fuel like a sieve while on the ground ).
The SR-71's skin was subjected to extreme heat due to the friction generated by flying at Mach 3+ for extended periods of time. The designers settled on a Titanium-composite alloy that revolutionized high-speed design. The shadowy monster flew her first operation sortie in early 1968, and a total of 32 aircraft were built before the tooling was ordered destroyed. They remained in and out of operation with the USAF until the last three aircraft were formally retired from military use in 1998, although several SR-71s were flown by NASA until the final flight of the SR-71 on October 9, 1999.
Almost a decade later the Blackbird remains the stuff of legends. No other aircraft embodies the essence of raw speed and technological might to such an impressive degree. Unfortunately, modern advances in digital satellite imaging have probably ensured that the United States Air Force will never again be able to unleash such an impressive and untouchable reconnaissance vehicle.