Early Airbus proposals for a family of airliners centred around twin-aisle and single-aisle designs, and while the first two aircraft featured twin-aisles, the third member of the family introduced the single-aisle. Although it shared some aerodynamic similarities with its two larger cousins, the A320 is essentially an all-new design, incorporating state-of-the-art airliner engineering features. Among the technological, firsts are a full fly-by-wire control system with sidestick controllers, gust alleviation function for a smoother ride and greater fatigue life and a centralised fault display and warning system. Intended for the 737/MD-80 market, the A320 has seating for 150 to 179 passengers, these accommodated in a wider cabin than most single-aisle aircraft, allowing for far greater comfort and the ability to take standard baggage containers.

Go-ahead for the programme was announced on 2 March 1984, and on 22 February 1987 the first aircraft took to the air from Toulouse with CFM56 engines. The first 21 aircraft were the basic A320-100 version, but these have since been superseded by the definitive A320-200, this featuring an extra fuel tank and wingtip fences. Versions under consideration are a convertible passenger/freight model and an all-cargo freighter. In 1989 Airbus announced a stretched version, the A321 with.a 44.51m long fuselage. With 186 passengers in a two-class layout, this will fill the capacity gap between the A320 and A310.

In service the A320 has proved extremely reliable and economical. These factors, together with the advanced technology, have made it the best-seller yet for the Airbus family. Air France took the first delivery on 28 March 1988, and the type was certificated in 1989 for operations with the IAE V2500 high technology engine. The type has achieved major sales in the United States with Northwest and Braniff.