The early sales success of its Mystere-Falcon 20 series led Dassault to investigate the market prospects for a new short-range airliner, one in very much the same class as the Boeing 737. Subsequent sales of this latter aircraft confirmed the accuracy of the basic market research, but Dassault was unsuccessful in attracting more than one customer for its new venture, which became known as the Dassault Mercure.
Generally similar in size and external configuration to the Boeing 737, Dassault's new aircraft was of low-wing monoplane configuration with a circular-section pressurised fuselage providing accommodation for 120-150 passengers, or a maximum of 162 in a high-density arrangement. The tail unit was entirely conventional, and the tricycle-
type landing gear had twin wheels on each unit. Like the Model 737 the Mercure had two Pratt & Whitney JT8D turbofans, these being of the Dash-15 series which was one of the options available for the Model 737.
The cost of launching such a project was formidable, certainly beyond the resources of Dassault, but the company was fortunate enough to obtain from the French government loan support amounting to 56% of the estimated initial cost of 1,000 million francs. Dassault put in 14% of the total, the balance coming from risk-sharing partners.
The initial prototype Mercure (F-WTCC) flew for the first time on 28 May 1971, the last three letters of this specially chosen registration representing Transport Court-Courrier (short-range transport). This aircraft was powered by two Pratt & Whitney JT8D-11 engines, each of 6804kg thrust, but the second prototype (F-WTMD), flown on 7 September 1972, had the more powerful JT8D-15s. It had been the initial intention to give the go-ahead for manufacture after receipt of orders for 50 aircraft. Somewhat imprudently, however, production began after the receipt of an order for 10 aircraft from Air Inter, a French domestic airline, on 29 January 1972. The first aircraft went into service in May 1974 and the 10th in December 1975. Ten years later, in April 1985, the second prototype was refurbished and added to the Air Inter fleet. Designated the Mercure 100, the 156-passenger airliners, operated with an annual subsidy from the French government to offset the extremely high cost of spares, are due for replacement by similarly sized Airbus A320s in the near future. The Mercure 200 higher capacity version seating 186 passengers and powered by SNECMA CFM56 turbofan engines was projected but did not proceed.