Why I don't believe In MoM...

In the last couple of weeks a new discussion about the so-called „Middle of the Market“ or “MoM” aircraft broke out. Apart from that nobody really knows what this aircraft should look like (B757 successor or B767 successor or both, narrowbody or widebody, scalable to cover the B737 market or not?) or every potential customer wanting something different, I do not really believe in the launch of such an aircraft in the near future.


Airbus has no interest in such an aircraft. They have a good market position with their A321neo, especially the LR version and the future A330-800, although I don’t foresee large order volumes for that aircraft. For sure Airbus is studying the MoM, but (for now) for the pure purpose of looking into what Boeing could do and if and how Airbus would have to react to it.

Boeing would be the one to launch such an aircraft. But do they have to do it? Although the B737MAX has less orders than the A320neo, the amount of orders the B737MAX got is massive. The B737MAX8 is right in the sweet spot of the market and has a small advantage in costs per seat against the A320neo – if the LEAP-1B engine performs as advertised, what remains to be seen.

The B737MAX8 just had it’s first flight. the –MAX9 and the –MAX7 have to follow. So why unsettle your (potential) customers talking too much and eventually launching a new aircraft that would at least partly overlap with the B737MAX family?

Also, Boeing will probably feel a drop in cash flow during the transition of the B777 Classic to the B777X between 2020 and 2022, just when the MoM would need large sums of money for R&D spending.

But there is another aspect why I do not believe in a launch of MoM for a, say, 2024 entry into service:


It’s the engines, stupid!


To explain this, let’s go back to 2010: both CFM and P&W committed brand new engine developments to COMAC (CFM LEAP-1C) for the C919 and Irkut (PW1400G) for the MS-21. For both engine companies it was clear that both of these applications were not presenting a clear business case (to say it politely). So it was in the best interest of both CFM and P&W that Airbus went forward with the A320neo.

What is the situation today? Both CFM and P&W spend a hell lot of money to develop these two new engines and in building the infrastructure to build these engines for the announced production rates of the A320neo and the B737MAX and need to sell these engines now in the thousands to get the money back. At least CFM should have no real interest in MoM. P&W could see a potential to gain market share from CFM if they get onboard MoM. But what would be the reaction from Airbus if MoM would be launched? I would guess it would be a A320neo+ with a new wing, a taller landing gear and maybe including a A322neo+. So P&W would have to further invest into today’s PW1100G with another PIP (the first PIP is already announced for 2019) or a 2nd generation GTF engine.

And how much better would a MoM aircraft then be? Would it justify to invest billions of dollars into an aircraft that is maybe 5% better than the refreshed aircraft of the competitor, who can sell his product for a better price then? I don’t think so…


What about Rolls Royce? They are working on their own version of the Geared Turbo Fan called Ultra Fan. But a MoM launch decision by Boeing this year would definitely too early for RR to get onboard. The risk for Boeing would be too high. To me it isn’t even clear that we would see two different engine suppliers on a potential MoM aircraft. The market could be not large enough for two engine supplier to get a sound business case – and CFM likely would “force” Boeing with money to be the one, because they would be the one to loose market share if MoM would be launched with a second engine.

So I don’t believe in MoM – until it flies…


  1. I am speculating here, but it seems to me that the only way a new MOM aircraft makes sense is when you put it in the context of the whole NSA discussion for Boeing. The aircraft we are calling the MOM aircraft will simply be the largest variant of the NSA. The smaller variants of the family will come out in subsequent years, and customers will convert as appropriate to their needs, and timelines.

    The NSA architecture will be all about bringing the experiences from previous projects to the 737 replacement product line, and to your point, scaling up the engines to allow for larger diameter fans on the single aisle Boeing form factor.

    Boeing needs to do an aircraft with a taller stance to allow for larger diameter engines, or abandon the traditional underwing pylon engine design. They need to do something to allow for the next turn in the crank of engine efficiency, and that is the NSA aircraft, which will have a MOM scaled product in it.

    When you look at in that vein, the all three engine OEMs will want to be in the game, or miss out on the next 737 family. I am sure that the engine OEMs will be interested in participating in that program, as Boeing is likely going to make a reasonably good jump forward with this product, and they do a decent job of doing the economics too.

    1. Rob, of course in the end all three engine OEM want to be in the MoM game, but a) the business case has to be sound and b) for CFM and P&W it should not erode their sales of LEAP-1A/B and PW1100G and c) RR has to be "technology ready". This is why I think they would not be too happy if a launch of MoM would come too soon.

  2. I think there are too many unknowns for a sensible aircraft project. The single/twin aisle is one thing. I would love to see a twin aisle, but from the physics point of view a single aisle is the better solution. When oil prices come up again it is probably more rewarding to go for "leapfrog" technologies such as the open rotor. Boeing as company has sufficient powder for one shot before 2025, and I don't think they waste it for a market that isn't absolutely firm.

    1. @ Anonymous : suit yourself - why not 'have the cake and eat it' ? ... or reformulated, take a twin aisle in the guise of a narrowbody ... you'd combine the trip physics excellence of the latter with the leapfrog APEX of the former ?

  3. If the MOM is conceived as a type 753 MAX (the 2 G$ fingersnap avenue, no moonshot, just the 737 fuselage with fwd + aft fuselage plugs ---> 43 m long cabin, a new carbon wing, stilted up on long legs and fitted with 81" or larger fans - high BPR - MAX engines, etc), ie assuming Boeing will endorse the MAX Family concept till the bitter end, then the thrust class required for such a "753 MAX" (some geeks call it the MAX-10 ?) will approach 40 +/- klbf ... will there be some Leap or PurePower development version available to power such a contraption, at the corresponding timeframe, say, around 2020-22 ?

    1. EIS 2020: not possible! Remember that it took 5 years from launch to EIS of the A320neo - EIS 2022: the engine OEM; would have to begin NOW with development. But there is no aircraft specification and thus no engine specification. And Boeing is developing the B777X now and the B737MAX-9 is not done yet. A 2024 EIS is the earliest possible I can see, with all the Limitations I described above.

    2. EIS by 2024 means 1st flight of FTV1-FTV5 by 2022 ... reformulated, 5 sets of development engines will be required for the test flights ---> certification. You are telling me this is improbable. Let's hope in such case that a type PW1135G or Leap1A will suffice to power the '753 MAX' whatever that is ? However I think two competing OEMs should avoid using identical versions of the same engine. Further, by 2024 Airbus will have sold, built and delivered vast quantities of A321NEO or A321LR, reducing the Business Case for Boeing's MOM to whatever scarce left-over peanuts can be traced in the market. The prospects aren't brilliant for Boeing, it seems ? Unless they can afford risking to wait another year to grab the UltraFan to power a cleansheet MOM Wonderliner for EIS in 2025, combined in a Family with the mythic 737 replacement ... but that might be a bit too early, respect to stamping the MAX with the 'OBSOLETE' coin ?

    3. By 2024 a 2nd generation of the GTF or the LEAP would be possible - but as I said above, at least I don't see why CFM would be too much interested in it as their market share would not be much better than before as the MAX would see lower sales. PW could be interested as they would increase their market share - but with all the investment for the 1st generation GTF over the last 10 years the beancounters in the company could slow the hunger for market share.

  4. BernardP:

    Nobody wants to entertain the possibility of a MoM with a 3-engine design, using the existing PW-1100G from the A320neo?

    There is no rule stating that all future airliners must use only 2 engines.

    There are designs for 3 engines that differ from what has been used on the 727/DC-10/L-1011.

    Three engines does away with ETOPS, although these rules have become complacent and no longer mean much... ETOPS-370? Really?