Mailplane

A mailplane is an aircraft used for carrying mail. Aircraft that were purely mailplanes existed almost exclusively prior to World War II. Because early aircraft were too underpowered to carry cargoes, and too costly to run any "economy class" passenger-carrying service, the main civilian role for aircraft was to carry letters faster than previously possible. During the 1920s, some mailplanes in the USA were operated by the United States Army Air Corps. In the past, mail-carrying aircraft had to carry a special official emblem on the fuselages; in case of British-registered aircraft, a special Royal Air Mail pennant (a blue triangular flag with a crowned bugle emblem in yellow and the letters "ROYAL AIR MAIL" in white) would sometimes be flown as well.