parts of the engine and to purge any combustible mixtures in the event of a fuel or oil leak in the nacelle. Variants JT11-1 Proposed version with 26,000 lbs. thrust in afterburner; Mach 3 dash capability. JT11-5A Proposed version with 32,800 lbs. thrust in afterburner; Mach 3+ capability. JT11-7 Proposed version with 32,800 lbs. thrust with afterburner; Mach 4 capability. JT11D-20 (J58-P-4) Production version for the SR-71. J58-P-2 proposed for a US Navy fighter, canceled mid-1959. J58-P-4 Applications Lockheed A-12 Lockheed M-21 Lockheed SR-71 Blackbird Lockheed YF-12 Specifications (JT11D-20) See also References Bibliography External links Pratt & Whitney J58 EngineHistory.org P&W J58 images SR-71 Online – J58 Engine Photos 1950s turbojet engines J58