Dassault Mercure
| Company type | Aircraft model |
|---|---|
| Industry | Aerospace |
| Predecessor | None |
| Founded | 1967 |
| Founder | Dassault Aviation |
| Fate | Production halted after 12 aircraft built |
| Headquarters | Martignas (near Bordeaux), France , France |
Area served | Europe (primarily France) |
Key people | Marcel Dassault (founder) |
| Products | Narrow-body twin-engine jet airliner |
| Parent | Dassault Aviation |
The Dassault Mercure was a narrow-body twin-engine jet airliner created by the French aerospace company Dassault Aviation. Dassault described it as the first major collaborative civil aviation project in Europe.
Introduced in 1967 to rival the American Boeing 737, the Mercure marked Dassault's inaugural venture into commercial airliners, having previously concentrated on military fighters and business jets. Its prototype took to the skies for the first time on 28 May 1971, and the aircraft entered operational service on 4 June 1974 with the French airline Air Inter.
To break into the US market, Dassault formed alliances with American companies such as Douglas, Lockheed, and General Dynamics, with plans for local production. Nevertheless, its comparatively limited range impeded broader sales success, resulting in a total production of only 12 aircraft between 1971 and 1975. The Mercure was withdrawn from service following its last flight in 1995.
Engineering
During the mid-1960s, Marcel Dassault and France’s Directorate General for Civil Aviation (DGAC) recognized a gap in the market for a short-haul airliner tailored specifically to short-distance routes. The DGAC encouraged Dassault to develop a 140-seat model as a French alternative to the Boeing 737.
With governmental support beginning in 1967, Dassault initiated development of a short-range jet. Early design efforts in 1968 centered on an aircraft seating 110-120 passengers powered by rear-mounted Rolls-Royce Spey turbofan engines; this concept evolved into a specification for a 150-seat plane capable of flying approximately 1,000 km (540 nm). Positioned at the higher end of its category, it contrasted with the smaller Boeing 737-100 and -200 models. The program was formally launched in April 1969.
Dassault capitalized on its experience in high-speed aerodynamics gained from military jets such as the Ouragan, Mystère, and Mirage series. The French government financed 56% of development expenses, recouped via sales levies, while Dassault contributed $10 million and primarily covered manufacturing costs. Total program expenditures reached $75 million, with unit prices increasing from $6 million in 1971 to $6.5 million in 1972.
According to Flight International, Dassault aimed at an underserved segment with the Mercure. Marcel Dassault chose the name Mercure (the French term for Mercury), inspired by the winged messenger god symbolizing swiftness.
Sophisticated computer-aided design tools were employed for wing development, resulting in an aircraft larger yet faster than the Boeing 737. A full-scale mockup was unveiled at the Paris Airshow in June 1969, followed by the prototype’s rollout at Bordeaux-Mérignac on 4 April 1971.
Flight testing
The initial prototype completed its maiden flight on 28 May 1971 at Mérignac, powered by two Pratt & Whitney JT8D-11 turbofan engines delivering thrust up to . The second prototype, fitted with JT8D-15 engines which powered all subsequent Mercures, flew on 7 September 1972. The first production model took flight on 19 July 1973. The Mercure earned its Type certificate on 12 February 1974 and gained Category IIIA all-weather automatic landing certification by September that year. Remarkably, one Mercure 100 flight was operated entirely by a female crew—the first commercial airliner to do so.
Dassault marketed the Mercure primarily to major and regional carriers as a replacement for Douglas DC-9 aircraft. Despite some initial interest, only Air Inter from France placed orders. Sales were constrained by factors including the dollar’s devaluation during the 1970s, the oil crisis, and especially the Mercure’s limited maximum payload range of just , restricting operations to domestic European routes. No international sales occurred; with only ten units sold—including a refurbished prototype—the Mercure became one of history’s least commercially successful airliners.
Mercure 200 project
After the commercial disappointment of the Mercure 100, Marcel Dassault advanced development on the Mercure 200C in collaboration with Air France, aiming to accommodate 140 passengers over a moderate distance. This new model attracted interest from several prominent U.S. airlines. In early 1973, the French government agreed to support the initiative by providing a loan of 200 million Francs, repayable after the sale of 201 units. Air France requested quieter JT8D-117 engines and a larger airframe, which led to an additional loan request of 80 million Francs. However, the government required Dassault to finance half of the development expenses, a condition that proved unattainable following the Mercure 100’s failure, resulting in the project's termination.
Dassault also explored alternative versions equipped with CFM International CFM56 engines and a supercritical wing design. In 1975, negotiations took place with Douglas and Lockheed for potential U.S. manufacturing and distribution, as well as with SNIAS in France. The Mercure 200-1 variant would be extended by to seat up to 184 passengers across two classes, while the Mercure 200-2 would maintain the original fuselage length but integrate the new wing design, accommodating up to 150 passengers.
The version featuring a wingspan of was designed with a wing area of , an empty weight ranging from , and a maximum takeoff weight of . Nevertheless, competition increased when Douglas introduced a stretched DC-9 model. Dassault considered partnerships with General Dynamics but was unable to reach an agreement. In 1981, Marcel Dassault made efforts to license production rights in the United States but met with no success.
Design
The Dassault Mercure was a jet-powered narrow-body aircraft engineered primarily for short-haul flights. It prioritized passenger capacity over fuel range, offering up to 17% more seating than the Boeing 737 at the expense of reduced range. Designed for operation by a two-person flight crew, Air Inter opted instead for three-man crews. According to Flight International, the Mercure’s fundamental design allowed for straightforward stretching in future variants without major modifications to its wing structure, cabin layout, or landing gear configuration. The landing gear spacing was deliberately set to accommodate longer undercarriage legs needed for larger engines and an extended fuselage.
The wing featured a conventional design with a thickness tapering from 12.5% at the root to 8.5% at the tip. Dassault’s design team optimized its shape and airfoil sections through extensive wind tunnel testing and computer modeling, resulting in an efficient lift-to-drag ratio and excellent block efficiency. The flaps formed a continuous spanwise unit when deployed for takeoff, eliminating the necessity for low-speed ailerons or jet exhaust cut-outs due to engines mounted low on deep pylons.
Production aircraft were equipped with two Pratt & Whitney JT8D-15 turbofan engines delivering 15,500 lb (69 kN) of thrust each, attached to underwing pylons featuring anti-vibration mounts. The propulsion units incorporated thrust reversers and noise suppression systems jointly developed by Snecma and Dassault. Considerable emphasis was placed on noise reduction in anticipation of potential FAA regulations within major markets such as the United States.
Dassault underscored the Mercure’s commercial appeal by highlighting its low operating costs on short routes, achieved through refined aerodynamics and lightweight structural design. The aircraft utilized an advanced fail-safe airframe manufactured using techniques derived from Dassault’s military production experience. It featured an internally developed triplicated fail-safe hydraulic flight control system without manual reversion capability. Air conditioning was managed by dual independent systems fed via cross-feed from engine compressors and an auxiliary power unit (APU), operable during takeoff, ground operations, or dual-engine failure scenarios. Electrical power comprised two independent three-phase AC systems at 120/128 volts and 400 Hz frequency driven by engine alternators, supplemented by a third AC system powered by the APU, alongside three separate 28-volt DC sources.
Operational history
Dassault envisioned large-scale production of the Mercure, aiming to deliver the 300th unit by the close of 1979. To facilitate this, four specialized manufacturing facilities were set up in Martignas (near Bordeaux), Poitiers, Seclin (close to Lille), and Istres. Production responsibilities were also shared across Europe through collaborations with Fiat Aviazione in Italy, SABCA in Belgium, CASA in Spain, and the Swiss National Aircraft Factory located in Emmen, distributing development risks among partners.
On 30 January 1972, Air Inter placed an order for ten Mercure aircraft, with deliveries planned from October 1973 through December 1975. The break-even threshold was projected at between 125 and 150 planes. Nevertheless, due to a lack of sufficient orders, manufacturing halted on 15 December 1975 after producing only two prototypes and ten operational units. Subsequently, Air Inter refurbished one prototype (registration number 02) for active service within its fleet.
The final two Mercure aircraft completed their last commercial flights on 29 April 1995. Throughout their service period, the Mercure accumulated 360,000 flight hours, transported 44 million passengers over 440,000 flights without any accidents, and achieved a remarkable 98% operational reliability rate.
Operators
Surviving aircraft
- F-BTTB, construction number 2, is displayed at the Technik Museum Speyer in Germany. Its interior remains as it was upon retirement and is viewable through a protective grille.
- F-BTTD, c/n 4, is showcased at the Musée de l’air et de l’espace located in Paris–Le Bourget.
- F-BTTE, c/n 5, functions as a ground training airframe at Montpellier–Méditerranée Airport for the Ecole Supérieure des Métiers de l'Aéronautique.
- F-BTTF, c/n 6, is currently stored at Bordeaux–Mérignac Airport.
- F-BTTH, c/n 8, has been preserved at Marseille Provence Airport.
- F-BTTI, c/n 9, serves as an instructional airframe at Bordeaux–Mérignac Airport.
- F-BTTJ, c/n 10 was formerly maintained at the Musée Delta near Paris-Orly but was dismantled in 2018; components have since been relocated to the Netherlands where they are utilized for exhibition and set design.