View of the XP-56 pursuit aircraft. Note contra-rotating propeller and minimal clearance of the lower vertical fin with the ground. The first example flew on September 6, 1943 at Muroc Dry Lake, piloted by John Myers.
Left, port side view of the Pratt & Whitney X-1800 SA-G with single-stage supercharger. Right, mock-up of the X-1800 A4G, with two-stage supercharger and large aftercoolers (visible at rear); such a unit ran in 1940.