This is a DC-9-50. This is a rather small aircraft used mainly by North American carriers. This plane can carry 139 people 1,635 miles. Major cutomers include Northwest (above), Continental, Hawaiian Air, USAirways, Air Canada, Aero California, Aero Mexico and Scandinavian Air Service (SAS) This photo was taken from Airliners.net and photo credit goes to Henry Jr Godding.