The Lockheed R6V Constitution was a large, propeller-driven, double-decker transport aircraft developed in the 1940s by Lockheed as a long-range, high capacity transport and airliner for the U.S. Navy and Pan American Airways. Only two of the aircraft were ever built, both prototypes. Although these two planes went into service with the Navy, the Constitution design ultimately proved underpowered and too large for practical airline use at the time. Although the Martin JRM Mars flying boat had a slightly longer wingspan, the Constitution remains the largest fixed-wing aircraft type ever operated by the U.S. Navy. Lieutenant Commander Byron E. Brown flew both of the Navy's Lockheed Constitution R6V aircraft for two years.
