19 (again). If it's not Eastern, then it's a Mohawk Airlines BAC One-Eleven 200 to Ithaca and Pittsburgh. Later Mohawk was acquired by Allegheny then, as USAirways, American West, which gobbled up American.
The real big airlines in the US today are Delta, America West masquerading as American, and Continental or Texas International masquerading as United. The next group include Alaska, Southwest, and JetBlue.