“To experience a J58 in full burner close up and personal is hard to describe. Picture a gigantic blow torch, 40 inches in diameter, putting out a blue-yellow-orange flame over 50 feet long. Imagine standing 30 feet from this, feeling the vibration and heat. You wear both foam plugs and earmuffs. Your ears still ring afterward, because the sound is conducted through your body. The back half of the engine transforms from dull gray to bright orange, seemingly transparent. The flame has little three-dimensional diamond shaped shock patterns about every two feet. I lost count at 13. It is both frightening and beautiful, an amazing demonstration of perfectly controlled power. And to think – this was done with 1950s technology.”
The above text is part of an interesting article sent to use by The Aviationist’s reader Tim White about the Pratt & Whitney J-58 engines that powered the SR-71 Blackbird, that was published years ago on the P&W website to mark the last time one of such powerful engines was lit up at night at Edwards Air Force Base.
The test took place on Sept. 12, 2002 and it was also the opportunity for the P&W team to dispose the remaining stock of JP-7 jet fuel specially formulated for the Blackbird “to withstand both the very cold environment at 80,000 feet and the very hot environment of the engine nacelle.”
H/T to Tim White for the heads-up.
Image credit: P&W
For those who might be interested—-I just
wrote an article on the P&WA J58 engine. It is the ASME’s Mechanical Engineering Magazine, December, 2013, pp. 36-41. Lee S. Langston, Professor Emeritus, University of Connecticut.