Lockheed’s magnificent P-38 Lightning was one of the most recognizable fighter planes in World War II. Less well recognized is the RP-38, a highly distinctive variation created in 1944 for a specific test purpose. The immense distances between islands in the Pacific Theater required a fighter type that could fly for hours between islands, yet have its pilot fresh for combat at any time. North American’s solution was its XP-82 Twin Mustang, essentially two modified P-51H fuselages combined in a twin-boom configuration, carrying two pilots to share the tasks of flying and fighting. But could a pilot successfully maneuver a fighter from a cockpit which was located far from the centerline? Would the unequal stresses disorient him, or make him less effective: Could the airplane itself maneuver as well as a conventional single-seater? To find the answers, Wright Field technicians removed the turbo-supercharger section from the left engine of the first P-38 to come off the production lines (s/n 40-744), and installed a second cockpit in the empty space over the wing. From this asymmetric port cockpit, several feet removed from the center of thrust, test pilots carefully evaluated the effects upon their own performance and that of the aircraft in various maneuvers. The experiment revealed no adverse effects, and although the Twin Mustang arrived too late for World War II, it joined the Air Force as an escort fighter and night fighter, and went on to a successful combat career in the Korean War.