The ingenious Douglas XB-42A Mixmaster was America's first 400 mph bomber. One of the most advanced reciprocating-engine aircraft flown. Two engines driving tail propellers were housed in the XB-42 “Mixmaster” fuselage. The Mixmaster pilot and copilot sat beneath individual Plexiglas canopies while the third crewman, a navigator/bombardier, sat behind a clear plastic bubble in the nose. The XB-42 was a top security WWII program which produced only two flying aircraft.