TYPE: Fighter, fighter bomber
ACCOMMODATION: Pilot only
POWER PLANT: One Chrysler XI-2220-11 inverted-Vee in-line engine, rated at 2,500 hp
PERFORMANCE: 414 mph
COMMENT: While the production of the Republic P-47 Thunderbolt had been emerging in ever-mounting quantities, Republic’s engineers had been investigating other ways in which the Thunderbolt could be improved. Two P-47D-15-RAs were assigned for testing the Chrysler XI-2220 engine, a 16 cylinder inverted-Vee liquid-cooled unit which transmitted its power to a propeller shaft by way of gears located midway along the crankshaft. The design was such as to produce an extremely finely-streamlined cowling of low frontal area, despite the engine’s ability to produce 2,500 hp. The converted aircraft were designated Republic XP-47H and remembered to a pre-war project, the Republic XP-69. Extensive redesign of the P-47 airframe was necessary to install the XI-2220-11 engine, with which was associated a General Electric CH-5 single-stage turbosupercharger in a modified installation in the rear fuselage. The first flight was not made until July 1945 and in one of the 27 flights a top speed of 414 mph had been recorded. The second XP-47H flew briefly after the war ended (Ref.: 9).