An engineering marvel, the Pratt & Whitney J58 is a one-of-a-kind engine, which powered the SR-71 “Blackbird” at speeds in excess of Mach 3, or 2,100 mph. What makes this engine so unique is the six bypass tubes, which directed airflow from the compressor stage directly into the afterburner. This allowed the SR-71 to operate at a much higher fuel efficiency than other afterburning jet engines when in full afterburner. The bypass tubes are easily visible in the middle section of the J58 on display.