Hello everyone,
I thank you for your participation. I answer each of you point by point by broadening the debate:
STBYRUD said
Well, take a close look at a LEAP-1B, and tell me that you don't find it in any way similar to a CFM56
Its still made by CFM, comes in equivalent thrust ratings to the CFM56-7B, and is probably closer to the -7B than the -3B is to the 7B
First of all STBYRUD your answer seems to me a little off topic, I did not speak of comparison between the performance of the CFM56 and the Leap, but the moment when will be decided the stopping of the chain of the CFM56, and the total replacement of this engine by LEAP.
But even so, I doubt that motorists would commit millions of dollars and a program of 5 years of research and development (is the rule for any new engine in this sector) to produce machines without real progress for airlines customers both in terms of consumption performance and engine thrust ... The standard for current engines is a dillution rate of 9 when at the time of the first CFM56 when reaching the 7 was a feat !!. ..And according to Safran Engines, the CFM56-3 thrust range was 82/105 kn compared to the 124.5kn of Leap 1B !
I think in fact that the current goal of any motorist is to lighten up the entire reactor by using more and more composite or other alloys conferring endurance and strength especially for blades of compressors and turbine , and the resistance of the combustion chamber, to space maintenance cycles, and to refine more and more the specific consumption by improving the dillution rate to give more autonomy to the aircraft equipped.
RVF750
The 7BE has been in production since 2014. The wing is hte same, more or less, so re-engining is perfectly possible, however, with the life expectancy of most CFM engines being very good, the real question is will the number of -NGs going to the boneyard provide enough to keep the new build NGs in the air for the next 30 years. Probably more than likely.
I think that a remotorization is not directly related to the type of wing but rather with the ancillary equipment accompanying the operation of the reactor: the kerosene circuit is it the same, the pumps are they the same, are the various accessories out of the engine block the same for a CFM56 as for a LEAP? If not, is their replacement expensive in addition to installing the new engine?
On the other hand, I would be interested to know the elements that determine the maximum life of a reactor in general, and different variants of the CFM56 more precisely (if possible)? Which elements of the reactor wear out the most and which others are so vital that it is necessary to replace it with a new engine? For how many hours of flight are the current CFM56-7Bs expected compared to LEAP?
Do not the conditions of use of an airplane affect the life of a reactor: for example low-cost airlines that have the practice of using their aircraft at the maximum of the number of hours they can do per day, and therefore the multiplication of takeoff cycles where the engines give their full power, does it not reduce more the life of the reactors that equip them than in other companies generally state?
The climatic environment in which reactors commonly operate can also, in my opinion, affect the overall service life of a reactor: if, for example, it is in a salty climate, the wear of the parts will be greater than for an aircraft operating in mountainous areas do not you think?
RVF750
The reason for the single supplier is cost saving for Boeing. One thing that really blows costs out of proportion, is too many options and choices. Airbus must be rueing the day they gave in on that with the A380...
Regarding the variety of engines proposed by an aircraft manufacturer, I think that opposite to you it gives the choice to companies to refine the performance of their aircraft in terms of operating costs and autonomy, and to play competition between engine manufacturers in terms of the performance of engines that each offers in terms of maintenance cost, endurance, and adaptation to noise and ecological standards. I think in fact that it is not up to the aircraft manufacturer to impose a particular type of engine, unless it has difficulties of integration with other competing models. It is true that for the Leap the nacelle of 737 MAX has been modified, but I do not know if it really is what dictates the only choice of this engine.
And finally another question to come back to our subject, is the production line of an engine stops automatically with that of an airplane (so with the chains of the A320 ceo and B737NG), or is it maintained for the used aircraft market for spare parts? Since planes are generally intended for a maximum lifespan of 40 years, the 737NG and A320 ceo will not leave the scene until 2030, is to say that the CFM56 continue to exist until that date?