When the Airbus A300 was being designed, Airbus studied many different sizes of plane. The Airbus A300B was chosen, and it was one of the smaller designs. When the A300B prototypes were made, many airlines asked for a plane which could hold more passengers. Airbus then changed to the A300B2 version, which was the first type to be made. Airbus noticed that many airlines also wanted smaller planes. Some airlines did not have enough passengers to use the A300. 