5X – what 5X?

During the last weeks Aviation Week had a few articles (here and here) about an alleged new Boeing widebody aircraft code-named -5X. More or less a NMA reloaded, this aircraft would be targeting the A330neo family, but in turn as well the 787-8/9.

Stop –say what? The 787 is right now not selling like hot cakes, but the A330neo not as well and the main reason is COVID-19, although also without the pandemic both aircraft would see lower production rates today than until 2019. So where is the point in developing a new aircraft there? The NMA, which was not able to produce a business case for Boeing, was shelved and was probably almost the same aircraft. Part of the problem back then was that the engine companies did not see the market as attractive as Boeing (officially) did and both CFMI and P&WA only wanted to develop an engine as a sole source.

So where is the reason to believe that now, two years later, it actually looks better for an aircraft like this?

The only thing Boeing should concentrate on is a new Single Aisle aircraft family! If Boeing would start an aircraft like -5X now with an EIS not before 2027, themselves as well as the engine companies would not have the resources to be able to counter an A320neo++ family with a new wing and engines that will then get a performance improvement package from the -5X engine(s). Also, as Scott Hamilton from Leeham writes today, the A220-500 is only a question of when, not if. So the lower end of the B737MAX would get increasing pressure once the - 500 is on the market. The B737MAX would be dead then, "killed" from the A220-550 from the lower end and from the A320neo++ and A321neo++ from the upper end – and in turn BCA would be dead!

But is it possible to design an aircraft family that can compete with the A220-500 on the lower end and a future (possible) A322? No, but the Airbus narrowbody aircraft family has two wings, two fuselages and different engines as well. So a clever scaling of the fuselage and the wings could do the trick for Boeing. Starting with the larger (6 abreast) family, starting just north of today's 737MAX-8 up to a A322 sized aircraft. After that scaling fuselage and wings down to a 5 abreast aircraft with a second or third generation of the PW1500G for example.

Just my 2 cents of course - but I see less than these 2 cents of value in a -5X! 

GE and the Geared Turbofan

There was quite a lot of hype in the last days around a story, first reported by Bloomberg, saying that GE talked with Airbus about a new engine for “a narrow-body jetliner in development”. In the article (and many that followed that first story) there is a lot of speculation about the aircraft: If it would be a successor of today's A320, a future stretched variant of the A220 or if that aircraft would in the end be the ZERO E (E for Emissions) aircraft announced by Airbus in September and the engine GE and Airbus discuss here would be an engine that would be used for that aircraft until a ZERO E engine (technology) would be available.

To make it short: this last consideration is – sorry to say it that way – bullshit! Whatever the source of energy of the future ZERO E aircraft would be – hydrogen or electricity comes to mind- the aircraft has to look very different from the design of a jet fuel powered aircraft and it would make no sense at all to hang a Geared Turbofan on an aircraft designed and optimized for zero emissions.

The fact that GE and Airbus talk about a new narrowbody is not a big story in the first place, as there are always discussions between airframers and engine companies about all kinds of possible future projects. But Bloomberg made a lot of noise due to the fact, that the design proposed by GE would be a geared turbofan, which is the engine design that today only Pratt & Whitney uses. GE always more or less dismissed the geared design in public because of the added complexity of the gear. Rolls Royce began developing their own geared engine concept called Ultrafan a few years ago.

So does GE not believe in the conventional turbofan anymore?

Not necessarily: believe it or not, but it is not the first time that GE proposes a geared design to an aircraft manufacturer. For the B777X, today's B777-9, GE also pitched a geared design towards Boeing, as did P&W at that time (I believe RR proposed a 3 spool design). But obviously Boeing went down the low-risk path of the GE9X engine, an evolution of the GE90-115B and the GENx engines, although the geared engines would have had a better fuel burn.

For the now (forever?) dormant NMA, Boeings reference engine was a geared turbofan. This makes sense, as at least in the beginning two of the three possible engine provider offered a geared design (P&W and RR), so we can only guess that GE (or CFM) also offered both variants (geared and non-geared) to Boeing. Later RR went out of the discussions as the aimed EIS timing was too early for the UltraFan.

So when today GE talks with Airbus about a geared engine, there is nothing sensational in there. Most likely the geared engine is just one out of two or more designs. And it most likely not more than a paper study, in which P&W and RR are involved as well. It is not more than the usual business of the future concept groups of all parties involved.

So do not expect an announcement of a new aircraft in the near future. Even a stretched A220 (-500) seems not to be on the horizon too soon...

Next (new) airplanes

After NMA is obviously no more, some people seem to believe, that Boeing could instead bring a refreshed B757 or B767 to market.

Is that viable? No, I would say, at least not for passenger traffic!

Both aircraft are late 1970’s aircraft, thus about ten years older than the A320ceo. Both were the first narrow- and widebodies with a two-crew-glass-cockpit.

But: the design of the airframe and the wing keep to be from these days, aside from getting winglets, saving up to 4% fuel burn.

So a new wing, along with the new engines, would be inevitable. Along with that goes a new center wing box. That means typically at least 50% of the development costs of a complete new aircraft.

But it does not stop here. A new cockpit with all the technology of B787 or B777X would be needed to make these airplanes attractive to airlines.

Now to the engines: for the B767 GEnx engines would be the likely candidate, and here the -2B version, as it has the right thrust and also a bleed air system. The GEnx though is an engine which was designed in the early 2000’s. The concept would me more than 20 years old if Boeing would decide to start development now with an EIS in 4 to 5 years. The basic aircraft concept would then be 50 years old.

The same is basically true for the B757: with the difference that there would not be an “off the shelf” engine with the right thrust available. But would any engine company spend $1bn for a brand new engine for a 50 year old fuselage? CFM/GE and PWA for sure not, as they have their engines in place on the A321XLR. So only RR could have an interest, but with todays news that they are laying off some 8000 people and delaying the development of their Ultra Fan this is more than questionable. In fact, I see RR in danger as they are so heavily exposed to the widebody market, which, in the opinion of all experts, will be the last market segment to recover.

So there won’t be a new aircraft from Boeing for the time being. CEO Dave Calhoun though says that the “true differentiator” of Boeing’s next aircraft will be “the way we manufacture and the way we engineer, as opposed to the… design of the airplane itself” (quote from the Flightglobal article). What does that mean? As I understand it: the B737MAX will stay the B737MAX, Boeing will (just) look into the cost of production. Well, hopefully they will get it right…

What does that mean for Airbus? A great opportunity, if they are bold and can get money in a similar manner as Boeing raised $25bn on the capital market. If Airbus can raise enough money with a lower yield than Boeing did, Airbus could use that money to invest in the so-called A320neo++, where the A320neo and the A321neo will get a new and larger composite wing and a new cockpit and both would be stretched to a “A320.5” (between todays A320 and A321) and a A322. Then Airbus would also need to develop the A220-500 and would have the perfect product line for the rest of the century and the early 2030’s.

Boeing meanwhile is stuck with the problems of the B737MAX:

1.     The grounded fleet at the airline customers has to be upgraded.

2.     The undelivered fleet has to be upgraded and to be delivered.

3.     Reacting to the potential A320neo++ would lead to the B737MAX being a non-seller

4.     The MAX is MAXed out: without a new wing, a complete new, longer undercarriage and larger bypass engines (from the A320neo) the B737MAX could not compete against the A320neo++. But would that make sense? No, then a complete new aircraft would be needed. Means another $15bn to be found somewhere, meanwhile back the $25bn bonds. Not easy…

So far for my theory…

Engine choices for NMA

It looks increasingly likely that next Boeing will launch the NMA -  or MoM, or 797, or whatever you want to call it.

One of the most interesting questions is the engine choice(s) that Boeing will make:

First of all, will the customer have an engine choice? Here the questions are:

-   does Boeing want to give the customers a choice

     and

- how large the engine OEM think the market for the new aircraft will be

The future is geared!(?)

The future in commercial aviation is geared, it seems:
Of course P&W and it's partners in the PWW1000G engine thought so when they started to develop their engines for the Mitsubishi MRJ, the Bombardier CSeries, the A320neo and the Irkut MS-21 and the Embraer E2-Jets.
But then, about three years ago, RR started developing their own engine with a geared architecture, calling their product (to be) the "Ultra Fan".
No I read in an article from Aviation Week that also Safran is working on a geared fan engine, under the umbrella of the european Clean Sky initiative, the equivalent  to NASA's CLEEN program.
A cross section of the engine concept can be seen on page 17 of this presentation.
My guess is, all engine concepts that CFM, RR and  P&W will eventually offer Boeing and Airbus for a replacement of today's A320 and B737 will have a gear between the LPT and the Fan!

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.

Why?

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

Discussion about the B757 replacement

Scott  Hamilton from Leeham has a post about the possible replacement of the B757.
 King5 then came out with it's own story, citing Scott.

I have to say I do not believe we will see a clean-sheet aircraft as a replacement for the B757 - at least not in the time frame Scott is mentioning. He sees a window for EIS opening in 2025, with Boeing probably being the first mover.
The reasons:

1. Business Case for B737MAX and A320neo. The A320neo will delivered from October 2015 onwards, the B737MAX roughly two years later (July 2017 as it looks right now). If a B757 replacement would be available in 2025, announced to the public by 2020, the B737MAX-9 would be dead by then. The B757 replacement aircraft (B757R) would be more economical on all missions - not just on the longer ones. In other words: if the -MAX9 would be more economical on shorter missions, there would be no justification for launching the B757R. In

Surprising engine choice

Last week Aviation Week came out with a story that Philippine Airlines opted for the V2500 and PW1100G for their ordered A321ceo/neo fleet and chose the Trent700 for their new A330-300 fleet.
As of today the whole PAL fleet is powered by either CFM or GE engines this would be a surprise if true - but also shows that PW gained market power through the buy of the RR share in the IAE consortium.
Looking at the A321 in particular though, the choice of the V2500 is not that surprising. From here I pulled all A320 deliveries from this year through August 31: about 84% of all delivered A321 have the V2500. In contrast, about 60% of the A319 and A320 were delivered with the CFM56. As the A320 counts for roughly 76.5% of all A320 family deliveries and the A319 for 7.5%, the CFM56 has the lead with 53.2% market share over the V2500. This is slightly down from 2011, when the CFM56 had a share of 56% for the whole year. In 2009 I found that the market share of the CFM56 was 61%. So with the shift to larger narrowbodies, like I described earlier, the market share in the narrowbody engine segment also changes.

Farnborough Airshow Orders

Here I will try to track all orders and commitments coming in at the Farnborough Airshow (main manufacturers only - sorry).


AIRCRAFT

Paris Air Show 2011

That was quite an event! I will focus on just some of the most important topics here, the most important of course being

A320NEO

1029 order and commitments! (plus a few more options) - Never ever in history there was an aircraft selling so fast. Of course, a comparison to the B737NG is unfair, as 15 years ago we did not have such big and emerging markets in China, India and all over Asia (more than 460 A320neos are ordered by Asian airlines so far). Also I am sure that a reengined B737NG or a NSA/B797 would sell as good as the A320NEO (or in the case of the – hypothetical – B797 even better). But let us roll back one year: there were many skeptics of the A320neo, saying that demand for such a “warmed-up” aircraft would just not be there. Others said that Airbus might be forced to convert many of the orders for the current A320 to the –neo model. Both are proved wrong today. Even Air Asia boss Tony Fernandes did not manage to convince John Leahy to convert some of the old orders to the –neo.

Now if American Airlines would really decide to order 100 A320neo (probably they are most interested in the A321neo) this summer, there would be lots of activities starting in Chicago and Seattle.

The A320neo brings us right away to the next big topic at this year’s Airshow.

LEAP-1A vs. PW1100G

Before I get started, please read what Addison Schonland wrote in his piece on AirInsight. As I laid out before I have my doubts about the performance claims of the LEAP-1A. And as I heard, CFM did more PW1100G-bashing at his media briefing just ahead of the Airshow than talking about their own product and it’s merits. A rock solid confidence looks different…

Nevertheless, CFM managed to get large deals at the Airshow. The largest, of course, was the order for 400+ engines for the 200 aircraft deal of AirAsia. But this was CFM’s to loose, as they are providing the CFM56 for the current 175 aircraft order from AirAsia, GE won with the CF6-80 for AirAsia’s A330-200 just recently and GE became a sponsor of Tony Fernandes F1 Lotus Team.

I did a prediction about A320neo orders and the respective engine choices just a week before the Airshow opened. I was wrong at SAS and Republic – both choose the LEAP-1A over the PW1100G. As it appears, I underestimated the market power of CFM, GE and GECAS.

I also expressed before that I think there could be an alliance between Airbus and CFM to keep potential CSeries customers away from ordering the Bombardier aircraft by giving them deals they cannot deny. This strategy can work with airlines which have business with CFM, GE and/or GECAS today.

Look at Republic: the whole Frontier fleet is powered by the CFM56 today - about half of the A319 fleet from Frontier is leased through GECAS.

Republic has the largest Embraer EJet fleet in the world, all powered by the CF34-8/-10. Most of the E170 in the fleet of Republic Airlines, one of Republics subsidiaries, is leased from GECAS.

So GECAS, CFM and GE have all possibilities to sweeten the LEAP-1A deal with discounts on spare parts and leasing rates – one thing that Pratt&Whitney can not do.

SAS on the other hand is a large B737NG customer and they also have a CRJ900 fleet powered by the CF34-8. They choose 2^nd hand B737-700 over the CSeries earlier this year. This decision was probably more cash driven, as leasing rates for used aircraft are of course cheaper than for new ones and SAS is going through a tough time right now. SAS has also A319 and A321’s in their fleet, powered by the IAE V2500. But firstly the V2500 powered fleet is much smaller than the B737NG fleet, and secondly, PW always has to deal with Rolls Royce on the V2500 business. And as RR has no stakes at all in the –neo business, they have no interest in building a bridge for PW at all.

One A320neo deal that did not materialize in Paris was the anticipated order for 50 aircraft from Qatar (as well as the “deferred” CSeries order). The A320neo will come one day of the other, just as U-Turn Al’s mood allows, but I guess the chances for the PW1100G are better here.  Although GE can throw their GGE90-115B business on the B777-300ER/-200LR fleet here (Qatar just ordered 6 more of them in Paris) and CFM powers 4 A340-300 in Qatar’s fleet, the A320 fleet is powered by the V2500 and PW might to persuade Qatar by making good deals on both the CSeries and the A320neo.

CSeries

John Leahy still thinks that Bombardier should scrap the CSeries program. As an Airbus employee he has to say that, regardless of what he thinks.

But as in the weeks before and at the Airshow there were five new customers announced (three of them unnamed so far), I think it became clear  that a growing number of airlines got convinced that in this market segment an optimized aircraft is better suited than, say an A319neo. Surprisingly, the CS100 got the biggest chunk of the new orders – maybe something to think about at Embraer…

I guess we will see a few other orders for the CSeries until the end of the year:

- Delta Air Lines

- Qatar (finally)

- GoAir, which just ordered 72 A320neo, hinted for a “raft” of CSeries soon to order

Boeing

Boeing did not raise the bar very high in the run-up of the Airshow, but did extremely well with orders, especially on the widebody front. It remains to be seen, if the revised A350-1000 can break the monopoly the B777-300ER enjoys in their segment. A stretched A350-1100X was denied by Airbus officials, but we will see…if the Rolls Royce managers are wise, they build in another 5% thrust margin above the 97klbf in their revised Trent XWB nacelle lines to cover for growth.

Scott Hamilton further explains Boeing’s success – I suggest to read his entry for more.

Other stuff

There was lots of other stuff to talk about – but I won’t, at least for today…

A350-1000 with more range - Update

Flightglobal has a new take on what is going on with the A350-1000. Contrary to Scott Hamilton, Max Kingsley-Jones thinks that the wing would be part of the design change, thus getting larger. This could indicate two things:
1. The Thrust/Weight-Ratio could get down without sacrificing runway performance as the larger wing would provide more lift. In other words, the MTOW could be lifted more than the ~5% gain in takeoff thrust, enabling the aircraft to carry more payload (especially cargo) over the reportedly new design range of 8500nm.
2. The investment for a larger wing and a "new" engine would make more sense, if another type would be added to the A350 family - call it the A350-1100 for now. With a further stretch of 4m it would have a fuselage length of roughly 80m, representing the ultimate stretch and would be a real B777-300ER competitor in terms of passenger capacity. The question then only is, if the range of the -1100 would be limited to 8000nm, comparable to the B777-300ER range, or if the -1100 would also get a range suitable for LAX-DXB (I now think that the 8500nm should work in >90% of the time for that route). If so, the "new" engine should really be a "new" engine - not just with an enlarged core, but also with a larger fan, as the thrust requirement would be more in the range of 105klbf. That would have implications to the basic design of the aircraft, especially the length of the undercarriage.

So Airbus could end up with the sub-families fo the A350 - the -900 and the -800 on the lower end and the -1000 and the -1100 on the upper end, very much comparable with the A340.

But again - until June 18 all is about speculation! But that's the fun with it...

A350-1000 with more range - implications for B737 successor?

Scott Hamilton just came out with this story: the A350-1000 will get more range (500nm) and a more powerful Trent XWB engine (+5000lbf).
A quick calculation revealed that 500nm more range need about 12.3t more MTOW. About 10 tonnes are for the extra fuel burned to cover the extra 500nm, about 2 tonnes needs the structure to carry the heavier aircraft, the balance goes for fuel reserves, as these are calculated in dependence of the actual flown range.
Thrust-to-weight ratio thus will be largely unchanged, runway performance probably a little bit worse, if the wing is unchanged. Compared to the B777-300ER, the wing is not heavily loaded, so I do not believe Airbus will enlarge the wing.
Scott writes that even the 8500nm will not meet Emirates desire of being able to fly Dubai - Los Angeles nonstop. The great circle distance for DXB-LAX is about 7250nm, so there is a 17% range margin. But is this enough to counter strong headwinds. A quick calculation shows that 17% of Ma0.85 (cruising speed of the A350) are equal to about 83nm/hr, meaning that if the average headwind on the route is higher than 83 knots, a technical stop would be necessary. I do not the average wind speed on the route over the north pole, but I could imagine that average wind speeds of 83knots and more ar possible.
The calculation also confirms that Emirates second desire - to add more pax - cannot be part of the change in the A350-1000 specification. So I wonder what is the rationality behind these changes? The 777-300ER has slightly less than the 8000nm of the "old" -1000 configuration, the 500 extra miles is good for a couple of extra city pairs, but does that justify the pain? The pain is probably bigger for RR than for Airbus, as these 5000lbf more of thrust will very likely mean that the whole core has to be changed, which means a lot of investment.
The main reason for that change might be to prevent Boeing from concentrating on the B737 successor. Airbus might hope that Boeing now feels more pressure on the B777-300ER and to concentrate R&D resources here and "only" to re-engine to B737 as Airbus always predicted.
And Airbus is apparently not alone: the recent Bernstein Research Note also suggests that Boeing should re-engine. Richard Aboulafia, VP of Teal Group, also thinks that a B737RE is the best answer to the A32XNEO, as one can reread in the AirInsight Paris Airshow Discussion transcript.
I guess we can expect the official Airbus announcement on Saturday, June 18th at the press briefing.
One is for sure - this years Paris Air Show is getting more and more interesting.

737 successor Part IV

In early March I wrote the first piece of this story and explained why I think that a "small widebody" seems unlikely as a 737 successor aircraft.
Hearing Boeing CEO McNerney at the conference call on Wednesday kind of confirms that. He said that the next new airplane will probably first address “the heart of the market,” which is 145 to 185 seats, McNerney said. “Which is not to say that we will leave the (7)57 space unaddressed at all.” (quoted from the seattle.pi blog).
So Boeing clearly will not back away from the "Southwest Airlines" market, which is (as of today) the lower end of that bandwidth, but SWA just this year also ordered their first batch of B737-800, representing the upper end of that "heart of the market".
Not leaving the 757 space unaddressed means they also plan to have an aircraft in the family with 200+ seats. But this would lead to a competitive disadvantage on the lower end, if all family members would have the same wing. If the 200+ seater should have a transatlantic range, the wing has to be considerably larger than today's 737NG wing. That would burden the 145 seat family member with a wing that is too large and too heavy. Trim drag would have to be used during cruise to keep the aircraft flying in level flight with the desired speed, as the large wing produces too much lift - alternatively the aircraft could fly slower, burning less fuel, but cutting productivity.
And by the time the new Boeing aircaft arrives, there could be, apart from the CSeries, another narrowbody - optimised for around 150 seats and probably lower range than the ~3000nm CSeries: a new 5 abreast aircraft from Embraer. With around 2200nm as today's EJets, a specific version of the GTF, the LEAP-X or even a new engine from RR, it could be better than the CSeries and the new Boeing aircraft.

Boeing of course could produce two wings - one for the lower end of the market and one for the upper end - in case of the 787 that strategy failed, but for reasons that do not apply in the narrowbody sector.

About the timing McNerney said:  “You’ll hear more from us at the end of the year.”
So, as I wrote in the third part of the story, we will obviously not hear anything spectacular from Boeing at the Paris Air Show - only a "guidance", probably further emphasizing that they lean towards an all new airplane, but not ruling out a reengining at all.

The first three parts of the story are here:
Part I
Part II
Part III

Geared Turbo Fan scores first

Now we have the long-awaited first battle "GTF vs. LEAP-X" fought out: the GTF (PW1133G) won at ILFC. Today they ordered up to 100 A320NEO aircraft, 60 of them will be powered by the GTF, the rest remains open.
Of course, this is only the first round of the battle, with many more to follow.
But many, including me, would have thought that a leasing company would opt for both engines, leaving their customers a choice.
Per CFM and PW, both engines promise the same reduction in fuel burn.
PW states that the GTF has 20% lower maintenance costs compared to today's engines - probably they compare the GTF to the V2500. CFM says maintenance costs for the LEAP-X will stay where they are with the CFM56 today. So at the end of the day the maintenance cost should be comparable, as the V2500 with it's 2nd HPT stage has "by definition" higher maintenance cost than the CFM56.
So the question is: why ILFC feels better with the GTF than with the LEAP-X - at least for the time being? Do they know something the public does not know?
One could say it is just a matter of a good deal, of course, and that could be right. PW might have offered ILFC a to good deal not to make. But on the other hand, pricing power should be something that CFM could play with - they have thousands of engines in the field and will have many more when the deal comes "online" in 2016 and beyond, so they could cross-subsidize more easily than PW can with their limited market power in the narrowbody market, as they are tied to RR in the V2500 - not to speak about the virtually non-existent widebody market power, where their only really selling products are the GP7000 (in a joint venture with GE) - the PW4000 picked up a little bit recently after it got the Advatage70 package.
Bottom line: it is unlikely that pricing power was the driving factor behind the engine decision from ILFC.
Let's wait for the next battles and their outcomes - maybe we can see some kind of a pattern then...

Oh, and by the way - I would love to know what our "friend" Saj Ahmad from the fleetbuzz Editorial has to say about the GTF now...

IndiGo launches the A320NEO

Well, here he is: IndiGo, the first customer for the A320NEO. A massive 150 aircraft order means a good start for the programme. Expect more big orders to come soon...
Coincidentally, Scott Hamilton talked about the prediction by Buckingham Research that Boeing will come out with two new models to replace the B717, B737 and B757 by 2018 and will launch this effort officially by late 2011 or 2012.
While Scott (or Buckingham) does not go into details, I guess this would be a single aisle aircraft for the reüplacement of the B717 and the lower end of the B737 and the "New Light Twin", which was briefly mentioned by Scott at the end of last year for the upper end of the B737 and the B757.
While it would be a good strategy in principle to replace three aircraft (families) with two new ones, I doubt that it will be that fast. How good can these aircraft be - or, in other words, how much better than the NEO? Engines for a 2018 EIS can only be slightly better than for the NEO with EIS 2016. And both CFM and PW have their hands full with developing the engines for the C919 and NEO (CFM) as well as the MRJ, CSeries, MS21 and NEO (PW). So one should not expect a completely new engine by the two manufacturers by 2018 but just minor improvements, which could also be sold to Airbus. And I do not expect RR to catch up in the 30k engine market by then - they lost the NEO competition and they have their hands full with their Trent programmes.
So the advantage has to come from the airframe. As of today, it is not clear if the A320/B737 successors will be build from carbonfibres. Bombardier opted for AlLi, apparently for good reasons.
To be clear, a new aircraft frame  by Boeing by 2018 would of course be better than the A320 frame, there would be 30 years between them. But would it be enough? - I doubt it!
The other question of course: does Boeing have the money to do it and the backing from their shareholders? Developing two aircraft takes a lot of ressources - manpower and money. If they do it, I expect the japanese to take over large parts of the responsibility for the smaller aircraft.
Another fascinating year in aviation just started!