First flown in June 1974 the Ecureuil was designed for the civilian market and introduced many features including the Aerospatiale 'Starflex' rotor system. Built from composites/fibre-glass, the rotor head was designed without the need for conventional mechanical hinging. It used the inherent flexibility of laminated composites for movement. This replaced the old style bearings and introduced laminated self-lubricating bearings. Fibre-glass was also used in the tail-rotor, formed by two blades attached to a composite beam which is both torsional and flexible and allowed the hinge system to be replaced. Aerospatiale also employed a large amount of composites within the fuselage, allowing for weight reduction, anti-corrosion and reduced operating costs. Powered by a single Turbomeca Arriel turbine-engine the AS.350 is produced in a civil and military variant and these have sold well overseas in both versions.

If the Alouette II represented the first family of French helicopters, the Puma the second generation and the Dauphin the third, the Ecureuil (Squirrel) is essentially a fourth generation, not just in terms of technology and performance, but above all, in the efforts made to simplify the production process, bringing assembly line techniques for helicopters increasingly close to those for ordinary motorcars.

The AS.350 in fact uses many automobile parts such as a cooling fan from a normal Citroen car and an oil radiator by another automobile manufacturer, while the Starflex rotor has very few parts, thereby eliminating the need for lubrication. Metal blades have also been abandoned in favour of fiberglass reinforced plastic ones which have a virtually unlimited life. The use of composite materials and pressed parts has contributed a great deal to simplifying the production process. The spacious cabin, for instance, is made of thermoformed polycarbonate semi-monocoque sections with ultrasonic welding. The bearings usually found in rotor hubs have been replaced by elastomeric ball joints which need no lubrication.

The first prototype of the AS.350 with a Lycoming LTS engine flew in January 1974 and the second (with a French Turbomeca Arriel engine) in February 1975. Deliveries began in July 1978 after eight pre-production models had been built. By the end of December of that year, the company had 459 orders for machines of this type, only six of which were for the military version. Essentially a civil helicopter, therefore, it has been a big success in the United States, where it was called Astar and customers could opt for an American or French engine.

Technical data for SA-350