The Pratt & Whitney J58, an engine officially designated by the company as the JT11D-20, is a turbojet engine manufactured by US-based engine maker Pratt & Whitney, which powered the Lockheed A-12 and its successor aircraft. This afterburning turbojet offers a unique compressor bleed design that gives this unique engine its impressive speed and massive thrust output, becoming one of the few engines ever to power an aircraft beyond Mach 2.