Abridged from Wikipedia, “Capital Airlines was a scheduled airline serving the eastern, southern, southeastern, and midwestern United States, (with) headquarters at Washington National Airport.  In the 1950s Capital was the fifth largest United States domestic carrier by passenger count (and sometimes by passenger-miles) after the Big Four (American, United, TWA, and Eastern.  Capital merged with United Airlines in 1961.”  Whether this card was official from Capital or not, we’re not certain; it serves mostly as a promotion for Shell Oil as the supplier for their fleet of Viscounts.  Unused aircraft postcard.  Grade: 1