During WWII, the unsolicited Douglas Aircraft proposal for a contra-rotating pusher propeller powered light bomber would become the most unusual and iconic U.S. military aircraft built during the war. Shades of ?Buck Rogers? to be sure. Amazingly, no major problems were encountered by this challenging design. The XB-42 ?Mixmaster? performed well, even setting a transcontinental speed record. Its fuselage housed two Allison V-1710 engines and their long propeller driveshafts. This gave the fuselage enough width to house two jet engines and the all-jet XB-43 proposal was born. While the XB-42 was designed, built, and flown within a year of Douglas first proposing it, the XB-43 ?Jetmaster? took many years to complete, mostly waiting for its promised J-35 engines to be delivered.