There is a lot of information on this thread that bears no respect for the truth and facts that disregard historical sense and detail.
1/- The engine : The design dates from 1968, at which time the only logical engine would have been the PW
JT8 and accordingly, the Mercure was closely tailored to the eventual D-17.
From the word go, Dassault envisioned an airliner that would make the best economic sense on short sectors, through very advanced aerodynamic design and structure lightness. As at that time the oil prices weren’t yet biting, the emphasis was on the quickest time possible, and that the Mercure did with some sparkling performance : climb and descent at IAS
380 kt / Mach .83, cruise at Mach .84… no wonder her pilots called her “The Air Inter Fighter “ !
What Prebennorholm refers to in his # 58 is the Mercure 200 project, a stretched version capable of 185 passengers but needing an engine in the 10 ton range : the M56 would have fitted quite nicely on that project but couldn’t be available before 1976… and the SNECMA study went into the (CF)M56 that they designed and built with GE
. In terms of calendar, it could still have worked alright for the Mercure 200. Problem was the French government was already spending a lot on Concorde and the A300 and Dassault didn’t have the resources – and the will – to go on its own and the -200 project was shelved.
2/- The A320 parentage : It’s another red herring as the initial basis for the A320 was the Aerospatiale SA
)">AS 200… and even that is doubtful as the studies of the JET are the true initiators of the Airbus SA
( for “single aisle” ) family.The man in charge of the design was Derek Brown who had nothing in common with either Dassault or Aerospatiale – and was based in Weybridge.
Of course, the single aisle airplanes all look alike, but the silhouettes hide some drastic changes : the A320 was designed some 13 years after the Mercure and the technical solutions are several orders of magnitude apart.
3/- The three man cockpit . Contrarily to A.net wisdom, the Mercure was designed for two pilots.The problem was Pilot Unions’ politicking, led by the IFALPA and some of the most vocal – and powerful –syndicates, especially in France.
The 737 used in the Carribbean had a flight engineer on the foldable jumpseat. It’s worth noticing that the aircond-pressurisation panel was displaced to the right side of the observer panel, close to the O2 mask storage : The FE
had something to do !
It is also worth reminding that when Air France management couldn’t agree with the SNPL for a two-man cockpit, they simply cancelled their 737 order, postponing its EIS by some 8 years , until it became obvious that ther FE
was seeing the end of his usefulness on single aisle airliners… but still the eventual acceptance of the FE
-less crew on the 737 and the A320 led to a painful schism at the SNPL with the creation of the SPAC with the die-hard dissidents.
For the Mercure, the FE
was in fact very useful : its speed alone required another pair of eyes and hands to manage the systems and procedures, of which the CAT III autoland validation was a big time consumer.