Boeing 737 successor Part V

I swear that this is the last piece in that series - before the Paris Air Show!
A recent piece in Flightglobal as well as a blog entry from Scott Hamilton this week shows that inside Boeing there are diverging blocks: one wants a new airplane, the other wants to reengine the B737NG and it seems like a "put them all in one boat"-solution to do it both. With a A320neo family arriving from 2015 onwards and a hypothetic new model from Boeing arriving in 2019 or 2020, with the CSeries entering the market in late 2013 and probably another 5 abreast aircraft from Embraer arriving at the end of the decade, who then needs a reengined B737NG? And if the backlog is so big that there are filled delivery positions even in 2018 today with todays B737NG, a reengined B737NG would only get a handful of orders from customers which did not get a delivery slot from Airbus, Bombardier or Embraer before the Boeing NSA is available.
So doing both makes no sense if the NSA is really slated for around 2020 - but a later arrival, around 2025 could make sense, as the differentiation against the A320neo in terms of engine and aircraft technology and thus operating costs could be larger then. That thinking should behind when Albaugh (quote Flightglobal) "questioned whether such an aircraft would be "good enough with rising fuel costs and emerging environmental regulations" and whether it could stay in service for 50 years." (quote end)
In the meantime, a reengining would make sense and would give that reengined B737NG a life expectation of at least ten years. At last years european ISTAT conference I spoke with some appraisers about the (the not yet launched) A320neo and they said that it would need a production run of at least ten years - the same should be true for a 737NGneo.
A "mild" reengining, maybe even avoiding changes to the front landing gear, should not bind too many engineering resources and should put Boeing in the position to counter Airbus if they should announce any changes to the A350-1000 that would make that aircraft to a better competitor to the B777-300ER than before.

No new Boeing airplane in sight...?

Scott Hamilton has it here: chances that we will seen and hear an announcement from Boeing for a new airplane, call it 737RS, call it 797, are getting slim. Buckingham Research now says that they do not expect an announcement from Boeing for a new airplane at the Paris Air Show. An approval to offer would not come before the end of 2012/ early 2013.
As I argued earlier, there is no real technical case for a new aircraft in the 2020 timeframe. And if there is no technical case, there is no business case. No business man will spend $10-15 billion without getting a decent return, if he can get the same return by spending $1-1.5 billion, as Airbus does it.
I don't want to say that Boeing now will do the 737RE - but in my eyes it would do much more sense. And this is one if the rare occasions I agree with Richard Aboulafia, who just today at the Aero Club in Wichita said that Boeing should quickly go forward with the reengining.
If they do not move quickly, there is a real danger that long-time Boeing customers are moving to Airbus.

A problem with reengining for Boeing could be the emerging signs that the CFM LEAP-X could be a little bit behind schedule. At least there is no customer for the LEAP-X on the A320NEO yet. As EIS for the NEO is 4.5 years away, some airlines (as well as ILFC) seem to be confident enough to order the GTF, but not the LEAP-X. They could also wait another year or even two and decide then about the engine - means ordering one engine now that they are sure that the other is not ready in time? Leahy last week said that the LEAP-X would be available by about 9 months, but no more than 12 months after the GTF. As EIS of the NEO was moved forward by 6 months at the same time, that means that the LEAP-X would have been 3-6 months later than the GTF per original schedule. Three to six months should not really be the deciding factor when ordering an aircraft that is used for twenty years and longer. So there could be something more behind all that...

Boeing 737 successor Part II

A few days ago I wrote about a possible 737 successor, aka 797.
Every day I get a mail with the headlines from ATI (Air Transport Intelligence) and today there where two headlines that catched my eyes.

1. Boeing sets performance targets for 737 clean-sheet contender (10Mar11
   23:29 GMT) Boeing would like its possible 737 clean-sheet design to
   have a 15-20% improvement in fuel efficiency over today's
   model, VP for marketing Randy Tinseth says at the Asian
   Aerospace show in Hong Kong.
2. Boeing: Twin-aisle 737 replacement could increase aircraft utilisation
   (10Mar11 23:25 GMT) Boeing is evaluating how to reduce weight from a 737
   replacement with a wider fuselage accommodating two aisles,
   vice-president for marketing Randy Tinseth says at the Asian
   Aerospace airshow in Hong Kong.

Here are my questions (and in the unlikely case that Randy Tinseth reads this, I would be the most happy man to get the answers directly from himself):

1. Why does Boeing only target 15-20% better fuel efficiency over the 737? If this is all they want, they can go straight ahead with reengining (Mike Bair said that reengining would yield 11%) plus some (more or less) minor improvements like weight savings through more composites and aerodynamic improvements. As a reengining benefits from grandfather-rights, Boeing would not have to care for some safety regulations that were introduced after the EIS of the 737-100. If Boeing goes with an all-new aircraft, they would have to care for all these with a weight disadvantage for the new aircraft versus the B737NG from the beginning.
2. Aside from the problems I tried to describe in the earlier entry, I still do not understand how the twin-aisle concept reduces the time for passengers to board and de-board an aircraft. The bottleneck are always the doors, so Boeing should better build wider doors. And for some low-cost airlines they should maybe have an option to build in a same-sized rear exit door, as Ryanair usually does not use airbridges at the terminal but boards and deboards on the tarmac via stairs.

Looking forward for the Paris Airshow this year more than ever...

There are three more parts of this story:
Part I
Part III
Part IV

Boeing 737 successor

Reportedly, Boeing focuses on a replacement of the B737 rather than doing something with the B777 in the nearer future. Mike Bair, who leads the B737RS studies at Boeing, said in the interview with Bloomberg, that "Six or nine months ago, we were leaning toward a bigger airplane sooner" - meaning that Boeing did not expect Airbus to launch the A320NEO and now finds itself captured between Bombardier on the low-end side of the single-aisle market and Airbus trying to steal traditional B737 customers. So they have to react, but reading carefully the Bloomberg interview and also the latest blog entries from Flightblogger Jon Ostrower makes me believe that they are not really sure what to do. Basically, they have two choices:

• A 6 abreast family sized from 149 seats (to please Southwest Airlines in particular) to around 200 seats. That would mean, that todays -700 would grow a little bit, todays -800 and -900 could stay in cabin lenght were they are today. For sure, cabin diameter has to increase to "speed loading and unloading, with either a wider aisle or possibly two aisles".
• That brings us to the second option: a 7 abreast in 2-3-2 configuration with two aisles. That configuration would make it very hard to please Southwest with a 149 seater. The aircraft's fuselage would be heavy in comparison with a 6 abreast aircraft, as the extra aisle takes extra space you have to buid around. Then the 149 seater would have 22 seat rows, compared to 23 rows of the  -700 with 137 seats in Southwest configuration today. It would not only look like a "Mini Guppy" (see below), but the problem is that in case of "one engine out" the stabilizer has a small moment arm and thus has to have a relatively large area, comprising weight for the larger family members, which does not need the large stab. Vice versa is the case with the wing: to get exceptable runway performance and range for the largest family member (runway performance is today's weak point of the -900ER), the wing has to be sized accordingly, which means extra weight for the smallest member. Of course that's a problem of today's B737 and A320 families, too. But with the CSeries entering the market, which is optimized around 135 seats and trans-con range, there is an alternative available which does not have to make this heavy compromises.

Another question Boeing and the engine manufacturers have to answer (first for themselves) is: what are the improvements in SFC for an engine with an EIS 2010 compared to EIS 2013 (CSeries) or EIS 2016 (A320NEO, C919, MS-21).
Boeing today dismisses the NEO as the 15% fuel burn improvement would be not enough. Remember: fuel is about 40% of Direct Operating Costs (DOC), even for narrowbodies (the numbers in Jon Ostrowers interview with Mike Bair seem to be too low) and it could rise even further. Historically, SFC gets down by 0.5-1% per year. So the best we can expect for a EIS 2020 engine is 4% better than the NEO engines will be - and they could be upgraded as the V2500 and the CFM56 were upgraded several times in their life.
So where could the big advantage in DOC come from?

• Aircraft weight: the new aircraft will benefit from new and lighter materials. If you read the interview, it will probably not be a plastic aircraft but a will get a Al-Li fuselage, like the CSeries.
• Plastic wing with smaller wing area (compared to today's B737) with higher aspect ratio: that leads to lower drag, lower weight and better aerodynamics
• The first two bullets both lead to a lower thrust requirement, directly leading to lower fuel burn.
• Maintenance costs of the aircraft: as the B737 today is the airline's darling when it comes to maintenance costs I can't see where this could get dramatically better
• Maintenance costs of the engines: as these engines will (most probably) be enhanced versions of the LEAP-X and the GTF or something similar from RR (Advantage 2 or 3), the difference in maintenance costs to the NEO engines would be small if at all. They could be even higher, as one way to improve SFC would be to raise OPR and therefore core temperatures.

Conclusion: there will be an cost advantage of the 737RS/797 compared to the NEO: of course. But will it be a step change? I can't see it today. And there are alternatives like the Bombardier CSeries and maybe another 5 abreast model from Embraer - they will decide what to do after Boeing announces their final plans - what could happen in June according to Bair. So in the second half of the year, we should have an announcement from Brasil...watch out!

This is how a 130 seater in a 2-3-2 seat configuration would look like...



Meanwhile there are three more blog entries about the possible 737 successor:
Part II
Part III
Part IV