Southwest Airways  Douglas DC-3

NC63104, late 1940s, Ed Coates Collection. Southwest Airways (no relation to the currently highly successful Southwest Airlines) was founded in 1946 in San Francisco.  It provided service initially to Los Angeles and Medford, with intermediate stops and specialized in quick turn-around operations ("two minute stops") at minor stations.  In fact, the integral built-in stairs, which became a regular feature on many third level carrier's DC-3s was first developed by Southwest.  The two rare shots in this entry show (above) NC63104 (an ex C-47A-DL) in the late 1940s at a very undeveloped SFO, and a close-up of the integral stairway.  Southwest actually developed the idea of a purser issuing tickets on board, but never exploited the concept..  Years later the practice was taken up by other airlines culminating in the highly successful Washington-New York-Boston Shuttle.  

 N67590, early 1950s, Ed Coates Collection. Here's nice shot of two, now white-topped, Southwest DC-3s at San Francisco Airport in the early 1950s.   The furthest machine is N67590 (c/n 20191).  Both were ex military C-47A-DLs. By this time the airline was serving some 40 small communities from San Diego to northern California with innovative half-fare family plans. .