The Dassault Mercure is a twin-engined narrow-body jet-powered airliner developed and manufactured by French aircraft firm Dassault Aviation. According to Dassault, it was the first large-scale European cooperative civil aeronautics programme. During 1967, the Mercure was proposed as a French competitor to the American Boeing 737. It was Dassault's first venture into the commercial jet airliner market, the company having traditionally built fighters and executive jets. On 28 May 1971, the prototype conducted its maiden flight, while the type entered service on 4 June 1974 with French airline Air Inter. Attempts were made to market the type in the US, including partnerships with American manufacturers Douglas, Lockheed and General Dynamics, with the vision of producing it in the United States. However, the Mercure had very little success on the market, which has been attributed to several factors, including a lack of range in comparison to rival aircraft. As a consequence, there were only 12 aircraft constructed, all of which were built between 1971 and 1975. The Mercure performed its final flight in 1995. Development Engineering During the mid-1960s, Marcel Dassault, the founder and owner of French aircraft company Dassault Aviation, as well as other parties such as the French Directorate General for Civil Aviation (DGAC), examined the civil aviation market and noticed that there was no existing aircraft that was intended specifically to serve low-distance air routes. Thus, it was found that there could be a prospective market for such an airliner, if it were to be developed. The DGAC was keen to promote a French equivalent to the popular American Boeing 737, and suggested the development of a 140-seat airliner to Dassault. In 1967, with the issuing of backing by the French government, Dassault decided to commence work on its short-haul airliner concept. During 1968, the initial studies performed by the company's research team were orientated around a 110 to 120-seat airliner which was powered by a pair of rear-mounted Rolls-Royce Spey turbofan engines; as time went on, a specification for a 150-seat aircraft with a 1000-km range (540 nm) was developed. As envisioned, the new airliner would attack this market segment at the upper end with a 140-seat jetliner, contrasting against the 100-seat Boeing 737-100 and the 115-seat Boeing 737-200 variants then in production. In April 1969, the development programme was officially launched. This aircraft was viewed as being a major opportunity for Dassault to demonstrate upon the