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Dassault Mercure

The 150-passenger Mercure airliner was a French 737, meant to fly short routes. The joke about the Mercure was that its short range would never let it leave France. A worldwide fuel crisis made airlines seek more efficient use of more fuel-efficient aircraft. And the Mercure entered a market already dominated by the popular McDonnell-Douglas DC-9 and Boeing 737-200 aircraft, both of which had established loyal followings and both of which had longer range than the Mercure. The A320 and its derivatives now fly many routes for which the Mercure was designed.

In 1967, the aircraft manufacturer Générale Aéronautique Marcel Dassault (GAMD), which would later become Dassault Aviation, exposed its wish to enter the commercial airplanes market. So far, the manufacturer had only designed and produced military aircraft and business jets. The decision to launch a commercial jetliner came after the manufacturer held talks with potential partners for a medium-haul aircraft earlier in the decade which would eventually from a stand for Airbus. Dassault, in cooperation with the Direction Générale de l'Aviation Civile (DGAC) - the French civil aviation authorities - observed that a large number of air routes were short distances; on the 3,500 routes scrutinized, eight out of ten were shorter than 1,500 kilometers. Furthermore, a study outlined the need for up to 1,500 aircraft with a capacity between 130 and 150 seats in the years 1973 to 1980, and Dassault was hoping to roll out the 300th airplane by 1979.

On 9 April 1969, Dassault and the French government signed a Memorandum of understanding (MoU) for a twin-jet seating up to 135 passengers. In June, a one-to-one-scale model was first presented at the Paris Air Show at Le Bourget. The design of the airplane was to take advantage of the valuable experience gained with the construction of military aircraft, and first of all high-speed aerodynamics and low-speed sustentation. Nonetheless, the technical realization of the airplane was shared with foreign partners; ADAP (Belgium), Canadair (Canada), CASA (Spain), Fiat (Italy) and FW of Emmen (Switzerland) were involved in the construction even though they were to support 30% of the overall cost, against 14% for Dassault and 56% for the French government.

The French domestic carrier Air Inter (IT) appeared as a natural customer for Dassault. The airline was looking for an airplane larger than the Sud-Aviation Caravelle 3s it was operating (99 seats), with around 150 seats for the most popular routes of its network, linking Paris with the main metropolitan French cities (all within 750km from Paris). Boeing was looking to place 727-200s with the French airline, and had proposed interesting credit conditions. But Air Inter eventually opted for the French jetliner on 30 January 1972, placing a order firm for 10 units to be delivered from 1973 onwards.

The Mercure looked rather good on paper, with lower operating cost and breakeven load factor than those of its competitors. Dassault was also offering to equip the airplanes with an "all-time landing system" which meaning operations would not be disrupted with Cat. III weather conditions thanks to a Head up display (HUD). And last but not least, the French state was pushing to have the airplane placed with Air Inter in order to promote the Mercure abroad and ensure an alternate way to the French aviation industry in case the Concorde and Airbus programs would fail. But this was not an issue to Air Inter's management which saw the opportunity to be the sole airline associated to the design of this airplane. IT also received guaranties from the government as well as finance help for the Mercure program.

The design work was already under way at Dassault. A first prototype (F-WTCC) was completed in April 1969, with the certification target of 1973. Dubbed as "Mercure 01", it was rolled out at Mérignac on 4 April 1971 and performed its maiden flight on 28 May with Jean Coureau (Captain), Jérôme Résal and Gérard Joyeuse. It was subsequently presented at the Paris Air Show '71 as from 2 June with only 9 flights and 6 hours on the log. The prototype brought an important experience to Dassault engineers' for the primarily definition negotiations with Air Inter before an agreement was found.

While the prototype was completed at Mérignac (Gironde), the final assembly line for the second prototype and production airplanes was constructed at Istres (Bouches-du-Rhône) in a brand new factory. But Istres was only one of the four assembly sites alongside Martignas (Gironde), Poitiers (Vienne) and Seclin (Nord). These different locations were selected at the request of the DATAR (Direction de l'Aménagement Territoire et de l'Action Régionale - governmental agency for the French territory development) and were to allow for a massive production.

The contract with Air Inter stipulated the first airplane would be delivered on 30 October 1973, one year and nine months after the contract was signed. But very quickly, Dassault announced it would not be able to deliver the airplanes on time and had to pay for the lease of five Caravelle 12s to Air Inter, as well as pay for the associated costs. The Mercure was finally certified by the DGAC on 12 February 1974, with a 11-month delay on the initial schedule.

The Mercure was close to the newly-developed 737-200, even though it was slightly longer and had a 5-centimeter wider cross section. The competition was tough with the DC-9 and 737-200 with a smaller capacity (100-130 seats) and the 727-200 (150-190) at the other end of the Mercure's market. And more important: both manufacturers had been in the business for years, whereas Dassault was a new entrant. One of the fundamentals of the conception of the airplane was to set the rapidity standards on short sectors, with an important climb-rate (1,000m per minute), a low cruise altitudes, and an important speed at climb, cruise and approach (858km/h cruise speed and up to 925 km/h at 6,095m). The performances achieved by the Mercure still don't pale the comparison with today's subsonic airliners. It established two records, on Paris-Lyon (391km) with 27 minutes and Paris-Bordeaux (492km) in 31 minutes. Overall, the Direct operating costs (DOC) of the Mercure were around 25% lower than those of its direct competitors. The airplane's Specific fuel consumption (SFC) and speed were better than those of the 727-200 thanks to the important aerodynamic work and know-how of the Dassault engineers.

Some US carriers drew interest in the new Dassault airplane. But it became quickly obvious it would be tough for the French manufacturer to sell its product. First of all the Mercure did not match the range of the McDonnell-Douglas DC-9 and Boeing 727-200Adv, its two main competitors, which was a major drawback on basically any market outside Europe. Common joke about the Mercure was that its limited range would never allow it the leave France. While the first prototype was powered by Pratt & Whitney JT8D-11 engines (15,000lb), the Mercure 02 and the production Mercures would the more powerful and efficient JT8D-15s (15,500lb), which was part of the fuel performance improvement pack of 727-200Adv. But the engine was nonetheless as a fuel-guzzling engine which restricted the weight and performance of the Mercure.

The launch timeframe of the Mercure was particularly unfavorable to Dassault; the 1973 oil crisis and the global downturn was a formidable and unexpected turn for the market. Basically all airlines were forced to reduce capacities as well as costs, and the introduction of an all-new airplane was not particularly welcome. The radical change in the US Federal Reserve's monetary policy led to the devaluation of the US dollar after 1973, which benefited to the US manufacturers Boeing and McDonnell-Douglas, and was detrimental to their competitors. The philosophy with which the airplane was designed - shorter block/block times on short routes - was suddenly outdated, as airlines were seeking fuel-efficient airplanes and began to introduce a strict fuel saving policy that would be carried out well within the 1980s. Air France's (AF) decision not to order the Mercure, publicly announced in June 1973, brought a definitive halt to the program, making sales abroad almost impossible from then on. In July of the same, Sabena's (SN) selection of the 737-200 over the Mercure annihilated any chance of ever gaining any further order for the French-built airplane.

Nonetheless, the project was not cancelled and carried on for its sole customer, with the first series airplane making its maiden flight on 19 July 1973. The airplane was awarded its Certificate of Airworthiness (CofA) by the DGAC on 12 February 1974. Dassault tried to downplay the short range drawback of the aircraft with a proving flight performed by F-BTMD on Paris (ORY)-Casablanca (CMN) on 6 March 1974 with 130 passengers on board (1929km).

The first aircraft, F-BTTA was delivered to Air Inter 15 May 1974. After the integration into the fleet and the Orly's maintenance procedures, the first revenue was eventually performed on 4 June 1974 on the ORY-Lyon (LYS) route. The other nine airplanes were progressively delivered and entered into service on the "radiales" from Paris to the main Province cities, until 19 September 1975 when the tenth and last Mercure was delivered to Air Inter (F-BTTJ). The Mercure gained its Cat. IIIA certification on 30 September 1974 (minimum of 150m horizontal visibility and 15m of vertical visibility).

With no future ahead, the Istres production line of the Mercure 100 was closed down on 15 December 1975 with only two prototypes and 10 series aircraft produced. Despite, the very small fleet in service, Air Inter and Dassault had reached an agreement over the spare parts production, resulting in no impact on Air Inter's Mercure operations.

From the point of view of the technical crews, the Mercure was a pleasant airplane to fly; its servo-commands were very precise, the instruments' layout was well thought-out and efficient. Air Inter's pilots often called it "le chasseur d'Air Inter" (the Air Inter's fighter jet). This alone shows the overall spirit with which the airplane was designed, and the good perception it had with the crews and passengers.

As Air Inter was satisfied with its Mercure fleet, Air Inter ordered an eleventh airplane on 11 July 1983 to Dassault. Rather than resuming the construction of the type dropped eight years ago, the second prototype was retrofitted to IT's specifications. This included lengthening the fuselage which was initially shorter on the Mercure 02. The airplane registered F-BTMD was eventually delivered to the carrier on 08 March 1985.

The last revenue flight of a Mercure was operated by F-BTTB on 29 April 1995. With Air Inter, the Mercure fleet has logged some 360,815 flight hours and 430,916 landings. The airplane has performed well, without any major problem, and an overall on-time performance of 97% (+/-15 minutes). The type has carried around 50 million passengers during its 24 years in service with the French domestic carrier. The airframe was designed for a 42,500-cycle life, and this was achieved by F-BTTG before being withdrawn in November 1994.

Even before the Mercure 100 entered into service, Dassault had understood an airplane optimized for only 1,500km sectors would not appeal to any further customer and that the future of the Mercure lied in a more capable version. The idea of a beefed Mercure 200 emerged at GAMD in 1973 already, and the project was firmed up in 1974. The French government was again backing up the project, especially as Dassault considered powering this more capable Mercure with an adequate 10,000kg engine the French engine manufacturer Snecma was developing in cooperation with General Electric, after it rejected the idea of using the P&W JT8D-17. Talks were held with the Société Nationale de Construction de Moteur d'Aviation (Snecma) over the Mercure 200, but also with the SNIAS and McDonnell Douglas. Although nothing serious came out of these discussion, Dassault was still firmly convinced of the viability of its new project.

The St Could-based airplane maker presented a model of the Mercure 200 with two CFM56s at the June 1995 Paris Air Show. The airplane was basically a stretched Mercure 100 with new engines and a far more important fuel capacity. At the occasion his usual official visit, Prime Minister Jacques Chirac called for an international cooperation, re-launching the hope of a partnership with the Long Beach-based manufacturer. A second project, called Mercure-ASMR (Advanced Short/Medium Range) was presented to 55 airlines at Long Beach in October 1976, while Jean Coureau and F-BTMD traveled across the United States to promote the Mercure during the same month. The Mercure-ASMR was to have an all-new wing to improve its fuel efficiency, as well as a larger fuselage section. But it would retain some of the valuable engineering work for the original Mercure and thus keeping the development cost fare below that of an all-new airplane. The airframe was to be optimized for a range/capacity mix; the Mercure-ASMR would have carried up to 174 passengers on 2,750km, which was significant improvement over the 150 pax/1,000km (130 pax/2,000km) of the Mk. 100. The improved SFC was also to be achieved thanks a to much lower cruise speed; 700km/h (at 6,850m) against 857km/h for the Mercure 100.

Once again, Dassault was convinced it would a part of the single-aisle market thanks to the better efficiency of its Mercure. Air France, which was seeking a smaller airplane than its 727-200s to open up new routes and increase new frequencies, had drawn some interest in the ASMR project, and was followed by some US operators. But in the 1977, both partners had yet to secure any order and decided to drop the Mercure-ASMR project. The airplane would eventually never leave the drawing board.

The Mercure is a great airplane and despite its failure, Despite its commercial failure, the Dassault Mercure remains an important step for the French aviation industry of the 1970s, and even beyond if the consequences of its fate are taken into account.

The Dassault Mercure Production List
 Type  Serial nbr.  Registration  First flight  Delivery date  Current status
 Mercure (prot.)  01  F-WTCC  28/05/1971  -  Destroyed
 Mercure (prot.)  02  F-BTMD (F-WTMD)  07/09/1972  08/03/1985  Destroyed
 Mercure  1  F-BTTA (F-WTTA)  19/07/1973  15/05/1974  Destroyed
 Mercure   2  F-BTTB  02/05/1974  June 1974  Museum Spire
 Mercure  3  F-BTTC  19/06/1974  July 1974  Destroyed (?)
 Mercure  4  F-BTTD  22/07/1974  September 1974  Museam LBG
 Mercure  5  F-BTTE  11/09/1974  October 1974  ESMA Montpellier
 Mercure  6  F-BTTF  08/11/1974  ?  Bordeaux
 Mercure  7  F-BTTG  31/12/1974  ?  Morlaix
 Mercure  8  F-BTTH  11/02/1975  ?  Vitrolles
 Mercure  9  F-BTTI  17/03/1975  ?  Bordeaux
 Mercure  10  F-BTTJ  26/11/1975  13/12/1975  Parray

 ENGINE2 x Pratt & Whitney JT8D-15 turbo-fans, 7031kg
    Take-off weight56500 kg124562 lb
    Empty weight31800 kg70107 lb
    Wingspan30.56 m100 ft 3 in
    Length34.84 m114 ft 4 in
    Height11.37 m37 ft 4 in
    Wing area116.0 m21248.61 sq ft
    Max. speed925 km/h575 mph
    Cruise speed858 km/h533 mph
    Range w/max.payload756 km470 miles

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Page last modified: 11-07-2011 02:53:42 ZULU