Modern Engines Still Can’t Match It: How Pratt & Whitney’s J58 Physically Grew 6 Inches Inflight

Some of the most interesting aspects of the engineering of the Lockheed SR-71 Blackbird supersonic spy aircraft were how it handled thermal expansion and the extreme temperatures of sustained high-Mach flight. The SR-71 belonged to an era when engineers tackled extreme aerodynamic heating largely through innovative materials and mechanical design rather than today’s extensive computer modeling and simulation.