Airbus's first airliner, the A300, was envisioned as part of a diverse family of commercial aircraft. Pursuing this goal, studies began in the early 1970s into derivatives of the A300. Before introducing the A300, Airbus identified nine possible variations designated B1 through B9. A tenth variant, the A300B10, was conceived in 1973 and developed into the longer-range Airbus A310. Airbus then focused its efforts on single-aisle (SA) studies, conceiving a family of airliners later known as the Airbus A320 family, the first commercial aircraft with digital fly-by-wire controls. During these studies Airbus turned its focus back to the wide-body aircraft market, simultaneously working on both projects.