J-58 Archives

The Lockheed SR-71 Blackbird’s Pratt & Whitney J58 Engines Ran at Full Afterburner for Hours at a Time With Exhaust Temperatures Near 3,400 Degrees. At Mach 3.2 Cruise, Roughly 80 Percent of the Thrust Came From the Inlet, Not the Engine.

The J58 burned JP-7, a blend so hard to ignite that a lit match dropped into it goes out. Starting the engines required a...