Boeing introduced the 747-300 because it wanted to offer increased seating capacity, using a stretched upper deck. The first flight was in 1982.
In 1983, the airplane entered service on a Swissair flight. Unlike its predecessors, the 747-300 had a straight staircase to the upper deck rather than a spiral staircase.
The last delivery of the 300 was in 1990 to the Belgian carrier Sabena.