rheinwaldner
Posts: 1577
Joined: Wed Jan 02, 2008 4:58 pm

Re: Boeing 797 Discussion Thread - 2018

Sat Apr 07, 2018 7:07 pm

monomojo wrote:
rheinwaldner wrote:
Anyway, while any other ever designed aircraft is competitive in a rather narrow range window, you are asking Boeing to design an aircraft, that would be efficient over 1000nm as well as over 4000nm.

Absolutely no one is suggesting Boeing will or should do that.

Matt6461 suggested Boeing will do that.

Newbiepilot wrote:
I don’t think the 797 would be optimized for 4000nm, but rather it will be capable of 4000nm.

Capable or competitive? That's a huge difference. The reasoning to which I initially wrote a reply was that the 797 would be competitive from 1000nm to 4000nm. Plus cruise at .85M. That's the tough call I am talking about (to put it mildly). And, as Matt6461 correctly notes, competitive for a larger plane means that it must have significantly better per-seat efficiency than a smaller plane (see A380).
Many things are difficult, all things are possible!
 
User avatar
Stitch
Posts: 25703
Joined: Wed Jul 06, 2005 4:26 am

Re: Boeing 797 Discussion Thread - 2018

Sat Apr 07, 2018 7:31 pm

Newbiepilot wrote:
I don’t think the 797 would be optimized for 4000nm, but rather it will be capable of 4000nm.


"Capable" won't cut it - especially against the A321-200LR, which is "capable" of 4000nm, but not "optimized" for it (due to payload restrictions necessary to tank the volume and weight of fuel).


Newbiepilot wrote:
4000nm is closer to what a 787 is optimized for even though it can fly much farther.


MZFW range for the 787-8 and 787-9 is over 5000nm so I would argue that is (at least) what it is "optimized" for.

Using the ACAPs as a (very) rough guide, if you want to move 44,000kg a 767-300 will do it 2400nm, a 767-300ER will do it 4100nm and a 787-8 will do it 5500nm. A 767-200 will move 36,000kg 2100nm and a 767-200ER will move it 5000nm. So I would expect the 797s to shoot for similar payloads with ranges somewhere around halfway between the baseline and ER models.
 
Strato2
Posts: 320
Joined: Sat Sep 24, 2016 3:52 pm

Re: Boeing 797 Discussion Thread - 2018

Sat Apr 07, 2018 7:37 pm

Stitch wrote:
And depending on the size of these new engines, the optimum diameter might be greater than what the A321's clearance can handle. It would be somewhat ironic / karmic if Airbus finds themselves in the same position with GTF2 and UF with what Boeing found themselves with GTF1 and LEAP-X.


I think Airbus would be quite happy to find themselves with 40% market share against a clean sheet design.
 
User avatar
Stitch
Posts: 25703
Joined: Wed Jul 06, 2005 4:26 am

Re: Boeing 797 Discussion Thread - 2018

Sat Apr 07, 2018 7:48 pm

Strato2 wrote:
I think Airbus would be quite happy to find themselves with 40% market share against a clean sheet design.


:shhh: Don't let a certain someone hear that. :rotfl:
 
User avatar
NeBaNi
Posts: 357
Joined: Sun Dec 20, 2009 10:45 am

Re: Boeing 797 Discussion Thread - 2018

Sun Apr 08, 2018 3:36 am

Revelation wrote:
chidino wrote:
The more I think about this (my earlier post), the more intrigued I'm getting.

Boeing is working on its bread and butter: without saying it, they are replacing the 737. (Hear me out.) They are planning 50 years out with this model; discussions of replacing 757s and 767s are almost irrelevant. Boeing correctly picked up on the long-term PTP shift; now they are planning for a world with constrained space and ever-increasing demand. It's charming to roll out new models, but they have to fit on a stand somewhere, and this provides more capacity without infrastructure changes the airlines can't control. Also, the development kind of fits: they worked out the kinks with the expensive designer model (including outsourcing too much) and are ready for the next 10,000 unit bus. (And as to what happens to the 737? They keep selling them, silly.)

It would be criminal incompetence if they were not thinking about where NMA development would take them in the future. Keep in mind they had pulled together a lot of thoughts about NSA just before they decided to go with MAX instead, and the main issue they could not resolve was how to do high volume CFRP manufacturing at low cost. They are making it clear that NMA too is about how to get cost of manufacture down.

Mark my words, I think the SUGAR High design (pictured below) will have something to do with the new 737-replacement. Boeing also came up with a hybrid-electric SUGAR Volt design, so if electric technology takes off in the future, the SUGAR could be a platform that takes advantage of that. The limiting thing right now is battery technology, but Boeing has to plan a new aircraft for the next couple of decades, so it better be thinking about being able to compete with the aircraft designs of the 2040s-2050s.
Image
Plus, Boeing recently acquired Aurora Flight Sciences, which is known for collaborating with MIT on its "double-bubble" D8 concept (pictured below). So Boeing has a lot of options, but whatever it decides needs to be relatively future-proof.
Image
 
RJMAZ
Posts: 1011
Joined: Sat Jul 09, 2016 2:54 am

Re: Boeing 797 Discussion Thread - 2018

Sun Apr 08, 2018 5:20 am

rheinwaldner wrote:
Capable or competitive? That's a huge difference. The reasoning to which I initially wrote a reply was that the 797 would be competitive from 1000nm to 4000nm. Plus cruise at .85M. That's the tough call I am talking about (to put it mildly). And, as Matt6461 correctly notes, competitive for a larger plane means that it must have significantly better per-seat efficiency than a smaller plane (see A380).

The 797 will have an payload and range envelope where it will be more efficient per seat than a A321. No one doubts the 797 would have better CASM than the A321LR on a super long 4000nm flight. The A321LR is trading payload for fuel massively at this distance. Every 50nm extra you loose multiple paying passengers. Every bit of extra headwind you loose multiple paying passengers.

The 797 will have a payload and range envelope where it will be more efficient per seat than a 787-8. No one doubts the 797 would have better CASM than a 787-8 on a super short 500nm flight. The 787 simply has too much excess weight and empty fuel tanks carrying around.

Adding these two envelopes together will determine just how valuable the aircraft will be. The question is how far does the 797 advantage extend?

The 797 might have better CASM than the A321LR right down to 2500nm and then second best (737) CASM right down to 2000nm.

The 797 might have better CASM than the 787 right up to 3500nm and then second best (A330) CASM right up to 4000nm

This means it the 797 has the best CASM in the world for the ranges of 2500nm and 3500nm. It also is the second best aircraft in the world between the ranges of 2000nm and 4000nm. That is a very versatile aircraft and worth having in every fleet to do medium haul.

The maximum number of seats or the maximum range are all secondary to creating an effieciency advantage envelope as large as possible.
 
User avatar
monomojo
Posts: 58
Joined: Wed Apr 04, 2018 12:39 pm

Re: Boeing 797 Discussion Thread - 2018

Sun Apr 08, 2018 5:43 am

RJMAZ wrote:
rheinwaldner wrote:
Capable or competitive? That's a huge difference. The reasoning to which I initially wrote a reply was that the 797 would be competitive from 1000nm to 4000nm. Plus cruise at .85M. That's the tough call I am talking about (to put it mildly). And, as Matt6461 correctly notes, competitive for a larger plane means that it must have significantly better per-seat efficiency than a smaller plane (see A380).

The 797 will have an payload and range envelope where it will be more efficient per seat than a A321. No one doubts the 797 would have better CASM than the A321LR on a super long 4000nm flight. The A321LR is trading payload for fuel massively at this distance. Every 50nm extra you loose multiple paying passengers. Every bit of extra headwind you loose multiple paying passengers.

The 797 will have a payload and range envelope where it will be more efficient per seat than a 787-8. No one doubts the 797 would have better CASM than a 787-8 on a super short 500nm flight. The 787 simply has too much excess weight and empty fuel tanks carrying around.

Adding these two envelopes together will determine just how valuable the aircraft will be. The question is how far does the 797 advantage extend?

The 797 might have better CASM than the A321LR right down to 2500nm and then second best (737) CASM right down to 2000nm.

The 797 might have better CASM than the 787 right up to 3500nm and then second best (A330) CASM right up to 4000nm

This means it the 797 has the best CASM in the world for the ranges of 2500nm and 3500nm. It also is the second best aircraft in the world between the ranges of 2000nm and 4000nm. That is a very versatile aircraft and worth having in every fleet to do medium haul.

The maximum number of seats or the maximum range are all secondary to creating an effieciency advantage envelope as large as possible.


An 797 that could economically flex between a carrier's longer 737 routes and their shorter 788 routes would be very attractive. I think that would be a good reason why Boeing is happy to push the 788 at the upper-MoM segment (and make sure the 330neo gets pushed out) and have the airlines buy into it, if they're confident the 797 can complement it in a synergistic manner instead of exclusively.
 
RickNRoll
Posts: 1413
Joined: Fri Jan 06, 2012 9:30 am

Re: Boeing 797 Discussion Thread - 2018

Sun Apr 08, 2018 6:13 am

SomebodyInTLS wrote:
Planeflyer wrote:
Regards composites vs metallic frames and barrels vs panels I have a few questions:

Why did AB go with composite panels on the 350 if Al offered better capability? I mean does anyone really believe AB could not make an effective technical presentation on why composites was/is a Boeing fantasy?


I'm not at liberty to go into detail but when the drug like rush was at full hype, a lot of people fell for it.


Computer developments are much the same.

An IBM mainframe years ago had a feature called "Extended Memory".

For the PC for a short period of time there was "Extended Memory" and "Expanded Memory" available for users to overcome the 640K limit. For a short period of time the best option was "Expanded Memory".

IBM renamed the mainframe feature to "Expanded Memory" even though the mainframe and PC had nothing in common.

Software has its' periods of hype. Everything is called "i??????" all of sudden. Or even rebranded "i??????".
Just giving the customer what they want.
 
rheinwaldner
Posts: 1577
Joined: Wed Jan 02, 2008 4:58 pm

Re: Boeing 797 Discussion Thread - 2018

Sun Apr 08, 2018 6:20 am

Just a short reminder:

The only specific data point that we have, how good 797 economics vs a narrowbody could be, is this:
Dutchy wrote:
Some interesting remarks about the potential 797.
Rough translation:
In an interview with Luchtvaartnieuws.nl at the A4E Aviation Summit in Brussels, O'Leary says that the cost per seat mile are substantially higher than with the 737 MAX 200 he has on order.


This means, that whatever range and pax-count is doable by a narrowbody, the 797 will be second at best (because being substantially behind the MAX, means being behind the A321 too). In fact, if we keep in mind, that a larger plane must offer a solid efficiency bonus to make it worthwhile, we have to assume that short range competitiveness for the 797 is not possible and is therefore very likely also not foreseen in the mission specs.

RJMAZ wrote:
The 797 will have an payload and range envelope where it will be more efficient per seat than a A321. No one doubts the 797 would have better CASM than the A321LR on a super long 4000nm flight. The A321LR is trading payload for fuel massively at this distance.

As long the A321 can carry the number of pax of a rather low density long-haul config (don't forget, ANA has a 788 config with 158 seats), it will be unbeatable. The discriminator in favor of the 797 will be added capacity but not better efficiency at those ranges, that the A321 can do.

RJMAZ wrote:
The 797 might have better CASM than the A321LR right down to 2500nm and then second best (737) CASM right down to 2000nm.

That would mean, that the 797 would be competitive with narrowbodies in areas of range/payload landscape where A320/737 are the strongest. This is not credible. And not supported by feedback from the airlines (see reminder above)....
Many things are difficult, all things are possible!
 
JustSomeDood
Posts: 321
Joined: Fri Nov 24, 2017 9:05 am

Re: Boeing 797 Discussion Thread - 2018

Sun Apr 08, 2018 6:39 am

rheinwaldner wrote:
Just a short reminder:

The only specific data point that we have, how good 797 economics vs a narrowbody could be, is this:
Dutchy wrote:
Some interesting remarks about the potential 797.
Rough translation:
In an interview with Luchtvaartnieuws.nl at the A4E Aviation Summit in Brussels, O'Leary says that the cost per seat mile are substantially higher than with the 737 MAX 200 he has on order.


This means, that whatever range and pax-count is doable by a narrowbody, the 797 will be second at best (because being substantially behind the MAX, means being behind the A321 too). In fact, if we keep in mind, that a larger plane must offer a solid efficiency bonus to make it worthwhile, we have to assume that short range competitiveness for the 797 is not possible and is therefore very likely also not foreseen in the mission specs.


That statement by MOL makes sense for his particular airline, given that the vast, vast majority of routes that FR flies are <1000nm. No one's arguing that a MOM would be as efficient as a 737max 200 for those routes, almost certainly, an A321LR would look bad against the 737max 200 on those routes as well. Extending MOL's statement to mean that on a narrowbody would win out against a MOM, CASM-wise, for the entire 3500nm range that such a narrowbody is capable of, is highly misleading.
 
User avatar
seahawk
Posts: 7556
Joined: Fri May 27, 2005 1:29 am

Re: Boeing 797 Discussion Thread - 2018

Sun Apr 08, 2018 7:08 am

Boeing does not need to aim for those short routes, because that is where the 737MAX already shines. They need to aim from 1500nm to 4000nm and that seems doable, as the A321 was never designed for this route length and all Airbus could bring out will be a warmed over compromise of an old fuselage with a new wing, which even Airbus claims (when talking about the 777-9 and the A350) can not be fully competitive against an all new CFRP design.
 
User avatar
keesje
Posts: 11928
Joined: Thu Apr 12, 2001 2:08 am

Re: Boeing 797 Discussion Thread - 2018

Sun Apr 08, 2018 9:25 am

If an aircraft can fly 5000NM with a 25t payload, that same aircraft will be heavily compromized on the typical <100 minutes 180-220 seat flights that are the bulk of air-traffic. Sorry.

Unless it a gamechanging, youjustdon'tunderstand, pipedreamliner of course.
"Never mistake motion for action." Ernest Hemingway
 
rheinwaldner
Posts: 1577
Joined: Wed Jan 02, 2008 4:58 pm

Re: Boeing 797 Discussion Thread - 2018

Sun Apr 08, 2018 9:46 am

I agree with seahawk&Keesje. With my remarks I countered posts that said the 797 would be super on short-haul too. It won't (and it is not the goal).
Many things are difficult, all things are possible!
 
RJMAZ
Posts: 1011
Joined: Sat Jul 09, 2016 2:54 am

Re: Boeing 797 Discussion Thread - 2018

Sun Apr 08, 2018 1:51 pm

rheinwaldner wrote:
I agree with seahawk&Keesje. With my remarks I countered posts that said the 797 would be super on short-haul too. It won't (and it is not the goal).

Airport fees don't go up up linearly with weight.

An old Airbus A300 in max density has lower airport fees per passenger than an A321 in max density.

The shorter the flight the airport fees become a greater percentage of the total trip cost. So the 797 doesn't have to beat the A321 on fuel burn per passenger. On short haul the 797 can easily beat it on the other costs.
 
User avatar
NeBaNi
Posts: 357
Joined: Sun Dec 20, 2009 10:45 am

Re: Boeing 797 Discussion Thread - 2018

Sun Apr 08, 2018 2:42 pm

JustSomeDood wrote:
rheinwaldner wrote:
Just a short reminder:

The only specific data point that we have, how good 797 economics vs a narrowbody could be, is this:
Dutchy wrote:
Some interesting remarks about the potential 797.
Rough translation:


This means, that whatever range and pax-count is doable by a narrowbody, the 797 will be second at best (because being substantially behind the MAX, means being behind the A321 too). In fact, if we keep in mind, that a larger plane must offer a solid efficiency bonus to make it worthwhile, we have to assume that short range competitiveness for the 797 is not possible and is therefore very likely also not foreseen in the mission specs.


That statement by MOL makes sense for his particular airline, given that the vast, vast majority of routes that FR flies are <1000nm. No one's arguing that a MOM would be as efficient as a 737max 200 for those routes, almost certainly, an A321LR would look bad against the 737max 200 on those routes as well. Extending MOL's statement to mean that on a narrowbody would win out against a MOM, CASM-wise, for the entire 3500nm range that such a narrowbody is capable of, is highly misleading.

I think this post, including the comment my Michael O'Leary, inadvertently makes the case for a MOM. Boeing already has a good competitor in the single-aisle size: the 737-8/ 737-MAX200. The MOM complements that instead of trying to compete with it.
 
frmrCapCadet
Posts: 2350
Joined: Thu May 29, 2008 8:24 pm

Re: Boeing 797 Discussion Thread - 2018

Sun Apr 08, 2018 2:45 pm

Can't find a drawing program which would do the freehand Venn diagrams I picture so I will describe it in words. Passenger numbers on the vertical axis, and range on the horizontal:

The distance from the abused NBs to the abused 787/330 is smallest in the center of the diagram. There is more space to the upper left and the lower right. Wish I could draw it. I think the diagram shows the challenge and difficulty of doing a MOM right.

The insight of the Venn diagram is that the strength of any MOM (2 models) will be an oval, but perpendicular to the standard range/passenger curve reaching at some distance from the upper left to the lower right. The central oval is where the two models excel. The extended oval is where they are appropriately abused. The business case is how to manufacture it at a cost that makes it work.
Buffet: the airline business...has eaten up capital...like..no other (business)
 
User avatar
BlueSky1976
Posts: 1789
Joined: Tue Jul 20, 2004 9:18 am

Re: Boeing 797 Discussion Thread - 2018

Sun Apr 08, 2018 4:32 pm

seahawk wrote:
Boeing does not need to aim for those short routes, because that is where the 737MAX already shines. They need to aim from 1500nm to 4000nm and that seems doable, as the A321 was never designed for this route length and all Airbus could bring out will be a warmed over compromise of an old fuselage with a new wing, which even Airbus claims (when talking about the 777-9 and the A350) can not be fully competitive against an all new CFRP design.


Enter *GASP* all-new Airbus "small widebody", a clean-sheet CFRP response to Boeing's 797, capable of killing its efficiency...
You know, the "A321 with new wing" could be just smoke and mirrors tactic...

Time will tell. Until then, it's all just speculation.
Tarriffs are taxes. Taxation is theft. You are not entitled to anything.
If it's a Boeing, I'm not going.
 
rheinwaldner
Posts: 1577
Joined: Wed Jan 02, 2008 4:58 pm

Re: Boeing 797 Discussion Thread - 2018

Sun Apr 08, 2018 7:16 pm

JustSomeDood wrote:
No one's arguing that a MOM would be as efficient as a 737max 200 for those routes

The moment you said that, you and I are in agreement, that the 797 can not compete with a narrowbody over short ranges (beside that there are a couple of posters arguing it can).

RJMAZ wrote:
rheinwaldner wrote:
I agree with seahawk&Keesje. With my remarks I countered posts that said the 797 would be super on short-haul too. It won't (and it is not the goal).

Airport fees don't go up up linearly with weight.

An old Airbus A300 in max density has lower airport fees per passenger than an A321 in max density.

The shorter the flight the airport fees become a greater percentage of the total trip cost. So the 797 doesn't have to beat the A321 on fuel burn per passenger. On short haul the 797 can easily beat it on the other costs.

That's absurd. From the first to last sentence.

Hint: which airport (fees differentiate from airport to airport)? How much cheaper is the A300 in percentage of total cost for a flight? And how much if you pick average density (because thats a proper comparison)?
Many things are difficult, all things are possible!
 
User avatar
Matt6461
Posts: 2840
Joined: Wed Oct 16, 2013 9:36 pm

Re: Boeing 797 Discussion Thread - 2018

Sun Apr 08, 2018 7:30 pm

Rheinwaldner wrote:
Matt6461 suggested Boeing will do that [build an NMA that beats current NB's on shorthaul]


Let me take you back to my prior opinion, as I've said my mind is changing:

First, you have to recognize that a range performance penalty is measured in weight, not in miles.
A newer plane with better engines can have both greater range and less range performance penalty than an older plane.
A321LR's MTOW, for example, is ~35% higher than [OEW + payload] at max pax range.
For the ~same range, that ratio is ~47% for 757-200 and ~80% for 707-320.
The ratio determines the range penalty, not the nominal range. B707 suffered far more penalty for its ~4,000nm range than will A321LR.

Based on past reports and analyses of the NMA, I expected ~15% lower SFC and ~12% higher L/D vs. A321LR.
A simple Breguet calculation shows these numbers to produce ~5,000nm range with less range penalty than A321LR.
So if the A321LR is a good short-hauler, then the NMA should be as well - especially given two aisles for turnaround.
Past analyses by Bjorn at Leeham predicted on the order of 25% lower cash operating costs for NMA versus A321LR.

Now we read that Boeing may derisk the program by using more conservative engines and a more conservative design.
We also have a new report by Bjorn at Leeham saying that the NMA is only "competitive" with A321LR on cash operating costs.

These developments should significantly change the picture. The NMA business case is much less clear absent a big edge over A321LR on unit costs for both short and longhaul.

So to an extent I agree with you, but I don't agree with your method of analysis.
You've been just repeating a very superficial and common sense impression that a longer-range plane is always less efficient on shorthaul than a shorter range plane.
That "man on the street" intuition shouldn't be enough for an intelligent discussion, and it doesn't withstand historical and theoretical scrutiny.
 
User avatar
Matt6461
Posts: 2840
Joined: Wed Oct 16, 2013 9:36 pm

Re: Boeing 797 Discussion Thread - 2018

Sun Apr 08, 2018 7:44 pm

IMO if Boeing launches even a mediocre NMA it will be the final nail in the coffin for A330NEO.
With A330 gone, Airbus will respond with the tight 8ab MoM that Boeing seems afraid of building due to its impact on 787.
Airbus will probably clean Boeing's clock with that plane - dominating the NMA and a large portion of the 787 market.
 
User avatar
JackMeahoff
Posts: 72
Joined: Fri Apr 06, 2018 2:12 am

Re: Boeing 797 Discussion Thread - 2018

Sun Apr 08, 2018 8:38 pm

RJMAZ wrote:
JackMeahoff wrote:
Just one question about this MoM concept: will it be a 3-3 or 2-3-2 aisle design?

Or is there another layout that regulators will let them get away with like a 3-4 or 4-4?

None of those. Everything so far has pointed to a new design with a 2-4-2 as the minimum size. Basically a few inches wider than a 767-200. And the longer version a few inchs wider than the 767-300.

A few rumours point towards a lightweight 787 such as the wing would look identical and the very high thrust requirements. Obviously this would be quite short and stubby. If you picked the half way point between the A321 and the 787-8 the new NMA will be on the larger side of the halfway point.

I don't think anyone here still thinks it will be 3-3 and a few people who originally said 2-3-2 have since converted to 2-4-2 but slightly shorter fuselage. 2-4-2 is slightly better from an economic aisle area perspective.



So basically it will look short and stubby like an A310.

I like it...
 
Deeso
Posts: 23
Joined: Tue Mar 20, 2018 8:30 pm

Re: Boeing 797 Discussion Thread - 2018

Sun Apr 08, 2018 9:04 pm

Matt6461 wrote:
IMO if Boeing launches even a mediocre NMA it will be the final nail in the coffin for A330NEO.
With A330 gone, Airbus will respond with the tight 8ab MoM that Boeing seems afraid of building due to its impact on 787.
Airbus will probably clean Boeing's clock with that plane - dominating the NMA and a large portion of the 787 market.


It doesn't seem too over the top to say that with luck the Airbus will sell at most 500 or 600 A300neo in the entire product life (counting hypothetical freight and MRRT variants).

Pretty soon Airbus will have to think what to do in the next decade. They have said several that times a replacement for the A320 family won't come before the 2030's, but I guess they'll to start working on it in 2026 or so unless they are willing to let it slip later in that decade. If they decide to compete head to head with the MOM, they better start decide about in the next three years. Otherwise that might delay the replacement for the A32x.

Boeing is going to be quite busy in the shorter term handling the 777X and 797 at once.(I'm not counting the 737-10 MAX as it's a very low risk variant). Later in the 20's they have to decide between a 787 refresh or a much needed 737 replacement.
 
RJMAZ
Posts: 1011
Joined: Sat Jul 09, 2016 2:54 am

Re: Boeing 797 Discussion Thread - 2018

Sun Apr 08, 2018 10:37 pm

rheinwaldner wrote:
That's absurd. From the first to last sentence.

Hint: which airport (fees differentiate from airport to airport)? How much cheaper is the A300 in percentage of total cost for a flight? And how much if you pick average density (because thats a proper comparison)?

From my first sentence to the last my post was 100% factual. A 30 year old A300 has less airport fees per passenger than a brand new A321. This is why it will be quite easy for a lightweight, carbon, short range widebody to beat the A321LR.

Not all fees are flat rate by weight such as baggage handling. Here's the total fees at Narita Japan. I will break it all down for members on here. This is a good example of most airports.

74T A320 = $2052
569T A380 = $10348

A320 cost per ton = $27.70
A380 cost per ton = $18.10

Source: https://www.naa.jp/en/b2b/fap/airport/charges.html

Now lets do the A300 Vs A321 comparison.

We first must standardise the seating area per passenger. I use. 500 square inches per seat for max density config. E.g A320 is 18inch wide seat by 28inch pitch is 504square inchs. We have the A321 is 240 seats the A300 is 345 seats.

The takeoff weights for a 30minute flight will be empty weight plus 100kg per passenger plus 90minutes of fuel.

A300 takeoff weight would be 132T. 394kg per passenger
A321 takeoff weight would be 82T. 341kg per passenger.

The fees for Narita calculate as follows. Both would be code A noise.

A300 fees are 204600 + 26400 + 76950 + 13000 = 320950 yen
A321 fees are 127100 + 16400 + 68400 + 13000 = 224900 yen

A321 fees are $2114 or $8.80 per passenger
A300 fees are $3016 or $8.74 per passenger

So an 30 year old A300 has less fees per passenger than a A321neo.

Boeing should be able to beat the performance of A300 in all areas.
Empty weight per cabin area/passenger
Fuel burn per cabin area/passenger
Lower maximum takeoff weight per cabin/passenger

Airport fees will allow the 797 to stay competitive with the A321NEO even if it has slightly higher fuel burn on short trips.

So Airlines can either choose to have better comfort for equal economics or equal comfort for better economics.
 
RJMAZ
Posts: 1011
Joined: Sat Jul 09, 2016 2:54 am

Re: Boeing 797 Discussion Thread - 2018

Mon Apr 09, 2018 1:26 am

chidino wrote:
I've been struck by the lack of an overwhelming business case for the 797. Yeah, it fits a lot of tasks, but the fact that there's so much discussion shows the lack of that case -- and Boeing has never done anything this big without one.

Actually Boeing would have closed the business case long ago. The engineers at Boeing would probably laugh at all the newbies on here arguing back and forth. Most members here lack an understanding of basic engineering and things like the brequet range equation. Granted members here would know more than the average population. We can't expect every member to have a masters in aerospace engineering with a decade of experience.

The majority of my posts I have to break down numbers to the most basic values because members simply cant calculate it themselves. Sometimes the argument goes back and forth half a dozen times and each time I've gotta break it down even further for them until they get it. Some still won't believe numbers, they need 1000+ sales and in service fuel burn numbers to be convinced. They simply go back to the fact that there has not been a short range widebody since the A300. That was the first Airbus aircraft and the world market was extremely small back then. 561 aircraft over 30 years may appear small but that would be equivalent of 2000+ today based on todays market size.

The members who I can tell have an engineering background or are just love crunching numbers all day are the ones who are most confident that the Boeing NMA/MOM/797 can deliver the goods.
 
WPvsMW
Posts: 1318
Joined: Thu Mar 23, 2017 7:30 pm

Re: Boeing 797 Discussion Thread - 2018

Mon Apr 09, 2018 6:07 am

 
rheinwaldner
Posts: 1577
Joined: Wed Jan 02, 2008 4:58 pm

Re: Boeing 797 Discussion Thread - 2018

Mon Apr 09, 2018 7:33 am

Matt6461 wrote:
First, you have to recognize that a range performance penalty is measured in weight, not in miles.
A newer plane with better engines can have both greater range and less range performance penalty than an older plane.
A321LR's MTOW, for example, is ~35% higher than [OEW + payload] at max pax range.
For the ~same range, that ratio is ~47% for 757-200 and ~80% for 707-320.
The ratio determines the range penalty, not the nominal range. B707 suffered far more penalty for its ~4,000nm range than will A321LR.

You must be talking about something else. Your methodology of range performance penalty talks about performance. I was talking about relative efficiency over a span of ranges. Relative because it is the efficiency in relation to the competition that defines competitiveness. E.g. the 707 (and the 757) was competitive at short ranges despite your 80% figure. Many intra European flights were made with 707s and DC-8s (at times when DC-9s were already in broad use). And how does your methodology reflect that e.g. the 777-200 was subpar vs A333 on medium ranges or that the narrowbodies have overtaken many routes that were operated by widebodies 30 years ago?

What I was talking about was competitivness over a span of ranges (the Range Competitivness Range, RCR ™ by me). The whole MOM case is based on the notion, that a dedicated mid-range design would have sufficiently reduced operation cost vs. e.g. the 787, that it would be worthwhile to use it to those destinations it can reach.

So I ask you: if the MOM can be designed in a way, that it can compete well with narrowbodies over short ranges, why did Boeing not build the 787 the same way so no MOM would be needed?

The 787 seems to have an efficiency disadvantage below 4000nm. This might be "man on the street" intuition, but it is anyway the truth. The capability to fly double as far takes its toll at some point. So what applies to the 787 (and any other mid or long plane) should not apply to the 797 anymore? That does not pass the smell test.

RJMAZ wrote:
Airport fees will allow the 797 to stay competitive with the A321NEO even if it has slightly higher fuel burn on short trips.

So Airlines can either choose to have better comfort for equal economics or equal comfort for better economics.

I respect the persistence how you fight each day for a new idea that does often not hold water. That said, this must be joke, right?

For you to pass the smell test, you surely can give me a number of examples, where the airport fees have made a larger airplane competitive, that was otherwise inferior?

Some more points, why airport fees wont be a discriminator:
- Have you noticed the smallness of the relative delta? 0.6% cost difference between the two per pax. The impact on the overall efficiency is so tiny, that nobody will care if it gets double as bad!!
- You say, that 797 operators saving 1% airport fees per pax, will thus accept a slight higher fuel burn. That's correct as long as the fuel burn is less than a whopping 0.25% higher (because fuel accounts for roughly four times as much as airport fees in a typical narrowbody cost breakdown)!!
- Why did the A300 not survive longer, if it was so favored by airport fees?
Last edited by rheinwaldner on Mon Apr 09, 2018 7:48 am, edited 1 time in total.
Many things are difficult, all things are possible!
 
rheinwaldner
Posts: 1577
Joined: Wed Jan 02, 2008 4:58 pm

Re: Boeing 797 Discussion Thread - 2018

Mon Apr 09, 2018 7:47 am

RJMAZ wrote:
The majority of my posts I have to break down numbers to the most basic values because members simply cant calculate it themselves. Sometimes the argument goes back and forth half a dozen times and each time I've gotta break it down even further for them until they get it.

Thanks for your numbers, if you put them properly into full contect, we see that your conclusion is rubbish.
Many things are difficult, all things are possible!
 
RJMAZ
Posts: 1011
Joined: Sat Jul 09, 2016 2:54 am

Re: Boeing 797 Discussion Thread - 2018

Mon Apr 09, 2018 8:01 am

rheinwaldner wrote:
Why did the A300 not survive longer, if it was so favored by airport fees?

The A300 starts on parity in terms of fees but as range increases the old tech engines and older non supercritical wing meant it's CASM got worse. So the newer A320's and 737NG's soon had an advantage across the board.

The 797 will have no such problems. It's big wing will provide a better lift to drag ratio than any narrowbody aircraft, it's engines will have equal or superior fuel efficiency. So it will start on parity in terms of airport fees just like the A300 as range increases its CASM will not get worse.

When you require a A321 or 737 to fly 3000+mm it will be taking off at or close to maximum takeoff weight. This means the initial cruise altitude is very low due to the small and overloaded wings. The fully loaded A321LR can not even reach 30,000 feet for the first few hours of its flight. This affects the entire average fuel burn for the trip.

The 797 will most definitely take off and go straight up to 35,000+ft on a 3000nm flight. The higher cruise altitude will improve fuel burn significantly. This payload range point is where the 797 will become the most efficient aircraft. It will extend up until the 787-8 takes over which would be potentially up around 4500nm.

Small deltas of 0.6% and 1% often translate into market dominance.
 
rheinwaldner
Posts: 1577
Joined: Wed Jan 02, 2008 4:58 pm

Re: Boeing 797 Discussion Thread - 2018

Mon Apr 09, 2018 8:23 am

RJMAZ wrote:
rheinwaldner wrote:
Why did the A300 not survive longer, if it was so favored by airport fees?

The A300 starts on parity in terms of fees but as range increases the old tech engines and older non supercritical wing meant it's CASM got worse. So the newer A320's and 737NG's soon had an advantage across the board.

The 797 will have no such problems. It's big wing will provide a better lift to drag ratio than any narrowbody aircraft, it's engines will have equal or superior fuel efficiency. So it will start on parity in terms of airport fees just like the A300 as range increases its CASM will not get worse.

When you require a A321 or 737 to fly 3000+mm it will be taking off at or close to maximum takeoff weight. This means the initial cruise altitude is very low due to the small and overloaded wings. The fully loaded A321LR can not even reach 30,000 feet for the first few hours of its flight. This affects the entire average fuel burn for the trip.

The 797 will most definitely take off and go straight up to 35,000+ft on a 3000nm flight. The higher cruise altitude will improve fuel burn significantly. This payload range point is where the 797 will become the most efficient aircraft. It will extend up until the 787-8 takes over which would be potentially up around 4500nm.

Small deltas of 0.6% and 1% often translate into market dominance.

We were talking about 1000nm not 3000nm. You are moving the goalpost by the factor of three. 3000nm of course is within the RCR (range of competitive ranges) of the 797.

Everybody knows, that small deltas in one area of 0.6% and 1% never translate into market dominance, because there are far more dominant discriminators. A 0.25% difference in fuel burn or acquisition cost already makes up your 1%...

And b.t.w. the big wing is bad for airport fees...
Many things are difficult, all things are possible!
 
User avatar
Matt6461
Posts: 2840
Joined: Wed Oct 16, 2013 9:36 pm

Re: Boeing 797 Discussion Thread - 2018

Mon Apr 09, 2018 8:37 am

Rheinwaldner wrote:
What I was talking about was competitivness over a span of ranges (the Range Competitivness Range, RCR ™ by me).


I don't see conceptual clarity in this reply sufficient to respond.

Rheinwaldner wrote:
Some more points, why airport fees wont be a discriminator:


You and RJMAZ are missing an important factor: slot acquisition cost.
The ability to fly to/from congested airports depends on having slots, for which a price is paid additional to landing fees.
Sometimes this cost is explicit as with secondary markets for slot trading.
More often it's an implicit opportunity cost: any flight from a congested point means you forego another flight to/from that point.
The most expensive documented slot trade, AFAIK, is Oman Air's acquisition of a prime LHR slot for $75mn. https://centreforaviation.com/insights/ ... ity-267222

If a slot's market or opportunity cost is $20mn, if we depreciate/capitalize the slot at 10%/year, and if we use the slot 100%, then the roundtrip cost allocated to slot acquisition is $5,480. On a 1.5-hr flight, that's ~25% of A321's total trip cost. A 40% bigger NMA would save ~10% cost per pax.

Slot economics probably explains why the less-efficient A330 carries much of Asia's shorthaul traffic between megahubs. Probably also explains UA's use of 772's from its biggest hubs, despite 772's worse efficiency vs. NB's. Many other examples.

[aside for longtime fans]Airbus claims slot costs are a reason for A380, but it doesn't work there. A380 has terrible economics on shorthaul that even slot costs wouldn't overcome. On longhual flights where A380 has decent economics, slot costs are only a small percentage of trip costs even from LHR.
 
rheinwaldner
Posts: 1577
Joined: Wed Jan 02, 2008 4:58 pm

Re: Boeing 797 Discussion Thread - 2018

Mon Apr 09, 2018 9:08 am

Matt6461 wrote:
Rheinwaldner wrote:
What I was talking about was competitivness over a span of ranges (the Range Competitivness Range, RCR ™ by me).


I don't see conceptual clarity in this reply sufficient to respond.

Which word did you not understand? ;) At least the questions should be very clear to answer.

Matt6461 wrote:
You and RJMAZ are missing an important factor: slot acquisition cost.

These are one-off costs. The slots an airline has at the congested hubs are often stable for years. Unless a new airline is ramping up their network, there are not much slot acquisition costs. Especially if aircraft like the A321 are used in a route fragmenter role, because fragmented routes tend to avoid congested hubs.
Many things are difficult, all things are possible!
 
DfwRevolution
Posts: 9209
Joined: Sat Jan 09, 2010 7:31 pm

Re: Boeing 797 Discussion Thread - 2018

Mon Apr 09, 2018 9:34 am

rheinwaldner wrote:
The 787 seems to have an efficiency disadvantage below 4000nm. This might be "man on the street" intuition, but it is anyway the truth. The capability to fly double as far takes its toll at some point. So what applies to the 787 (and any other mid or long plane) should not apply to the 797 anymore? That does not pass the smell test.


Intuition is not truth. Intuition is the kernel of a hypothesis, which cannot become "truth" until positively tested.

You're claiming the 787 has an "efficiency disadvantage" on routes under 4,000 nm. Efficiency as measured by what? Disadvantage versus what?
I have a three post per topic limit. You're welcome to have the last word.
 
User avatar
Matt6461
Posts: 2840
Joined: Wed Oct 16, 2013 9:36 pm

Re: Boeing 797 Discussion Thread - 2018

Mon Apr 09, 2018 10:17 am

Rheinwaldner wrote:
These are one-off costs. The slots an airline has at the congested hubs are often stable for years.


The same can be said of plane purchases - I guess plane purchase cost isn't part of operating economics?
News flash: businesses learned how to calculate long-term assets' impact on operating cost at least 2,000 years ago (Roman writers wrote about the necessary "yield" - compared to an interest rate - from purchase of a vineyard).
This is just poor economic thinking. Are you familiar with the concept of opportunity cost? If you aren't there's really no point to further discussion until you read up on it.

Rheinwaldner wrote:
Which word did you not understand? ;) At least the questions should be very clear to answer.


I didn't see any clear coherent thoughts in the post. As for the questions, they're just repeats of the same platitudes.

Let's make this analytically clear. I will attempt to summarize your thesis; tell me whether I'm right.

Thesis: Planes with greater range cannot be more efficient than planes with less range.

If that is not a correct statement of your thesis, please explain in a clear manner that does not veer into questions.
Last edited by Matt6461 on Mon Apr 09, 2018 10:22 am, edited 1 time in total.
 
rheinwaldner
Posts: 1577
Joined: Wed Jan 02, 2008 4:58 pm

Re: Boeing 797 Discussion Thread - 2018

Mon Apr 09, 2018 10:21 am

DfwRevolution wrote:
You're claiming the 787 has an "efficiency disadvantage" on routes under 4,000 nm. Efficiency as measured by what?

CASM? Or do you know something better to specify efficiency on a global level? No to forget I am replying to posts where CASM is used allover...

DfwRevolution wrote:
Disadvantage versus what?

MOM kind of aircraft. The A321LR in particular, the 797 and A321LR upgrades potentially. As this thread discusses the 797 I assumed that to be clear.
Many things are difficult, all things are possible!
 
User avatar
Revelation
Topic Author
Posts: 19136
Joined: Wed Feb 09, 2005 9:37 pm

Re: Boeing 797 Discussion Thread - 2018

Mon Apr 09, 2018 10:46 am

WPvsMW wrote:

Thanks for the post, but not so "late" ( "Posted on 12th March 2018 by Jon Ostrower" ).
Wake up to find out that you are the eyes of the world
The heart has it's beaches, it's homeland and thoughts of it's own
Wake now, discover that you are the song that the morning brings
The heart has it's seasons, it's evenings and songs of it's own
 
Amiga500
Posts: 1706
Joined: Tue Mar 03, 2015 8:22 am

Re: Boeing 797 Discussion Thread - 2018

Mon Apr 09, 2018 11:11 am

Matt6461 wrote:
You and RJMAZ are missing an important factor: slot acquisition cost.
The ability to fly to/from congested airports depends on having slots, for which a price is paid additional to landing fees.


Are slots paired with gates?

As in, if an airline decides to change from operating a 737 on a route to go with a 787 (or same for A320 => A330), is that "slot" then renegotiated based on the need for a bigger gate, or are the fees just adjusted?

[Or does it come down to airport availability on a case-by-case basis?]

A lack of available Code D gates could mean an airport cannot simply allow an airline to change from 737 to 797 in a specific landing/take-off slot.
 
RJMAZ
Posts: 1011
Joined: Sat Jul 09, 2016 2:54 am

Re: Boeing 797 Discussion Thread - 2018

Mon Apr 09, 2018 11:33 am

rheinwaldner wrote:
We were talking about 1000nm not 3000nm. You are moving the goalpost by the factor of three. 3000nm of course is within the RCR (range of competitive ranges) of the 797.

Everybody knows, that small deltas in one area of 0.6% and 1% never translate into market dominance, because there are far more dominant discriminators. A 0.25% difference in fuel burn or acquisition cost already makes up your 1%...

And b.t.w. the big wing is bad for airport fees...

I was covering all ranges from 0nm up to 5000nm when comparing the A321 to the 797.

On a 0nm flight airport fees will be similar on a per passenger basis. The heavier aircraft gets a slight bulk discount which makes it pretty much equal or competitive.

On a 1000nm flight the fuel burn per passenger will be on par. The better lift to drag ratio of the larger wing will allow slightly less thrust so it would cancel out any extra bulk of the 797. So at this range both are equal or competitive. This passes the "widebody with narrowbody economics" phrase in my opinion.

This fuel burn parity will extend to greater ranges but the A321 will eventually start to lose efficiency. As range increases the initial cruise altitude of the A321 becomes lower and lower and the 797 will take over. The point at which the efficiency gain starts to appear and the rate of the gain increase is up for discussion. The 797 will have a huge advantage at 3500nm but at what range did that advantage start to appear?

At 5000nm the A321LR would have to ferry that distance with no passengers. So it's CASM would be infinitely higher than the 797 at this range.

A 1% fuel burn delta is the difference between the A320 and 737 families and the A330NEO and 787 families. So it can make a big difference on market share.

Landing fees, baggage fees, parking fees, gate fees and slot costs they all work in the advantage of the bigger aircraft on a per passenger basis. The advantage might be very small but it is big enough to make the 797 more than competitive against the smaller A321.
 
User avatar
SomebodyInTLS
Posts: 1306
Joined: Wed Jun 15, 2016 12:31 pm

Re: Boeing 797 Discussion Thread - 2018

Mon Apr 09, 2018 12:02 pm

RJMAZ wrote:
The members who I can tell have an engineering background or are just love crunching numbers all day are the ones who are most confident that the Boeing NMA/MOM/797 can deliver the goods.


Ha ha! The members I can tell are engineers (or who know their brequet from their Breguet - not that I've seen that equation since university, so definitely no measure of credentials...) are the ones like Astuteman and Amiga500 (and more) who seem to deal in realism and nuance and don't just endlessly churn out meaningless numbers to "prove" their baked-in opinions.
"As with most things related to aircraft design, it's all about the trade-offs and much more nuanced than A.net likes to make out."
 
User avatar
Matt6461
Posts: 2840
Joined: Wed Oct 16, 2013 9:36 pm

Re: Boeing 797 Discussion Thread - 2018

Mon Apr 09, 2018 12:04 pm

Amiga500 wrote:
Are slots paired with gates?

As in, if an airline decides to change from operating a 737 on a route to go with a 787 (or same for A320 => A330), is that "slot" then renegotiated based on the need for a bigger gate, or are the fees just adjusted?


I can't say the global practice but I know of several U.S. airports where slot-gate pairing isn't a given.

Re fee readjustment based on plane size - I don't think that happens except for the weight-based landing fees, which are generally scheduled instead of negotiated (exception being rebates and other contracts).
The lack of size-based adjustment is a massive inefficiency across the entire industry. Airlines should be incentivized to use airfields most efficiently by up-gauging flights, and airport charges should be adjusted to reflect that policy. Instead, secondary slot trading is rarely legal, few slots are liquid even when it is legal, and airlines play slot-sitting and other anti-competitive games with current regulations.

RJMAZ wrote:
Landing fees, baggage fees, parking fees, gate fees and slot costs they all work in the advantage of the bigger aircraft on a per passenger basis.


...and because these fees become more important at shorter ranges, they can counteract the relative fuel disadvantage - if any - of the larger plane. In other words, the CASM edge may be constant at both 1,000nm and 4,000. Only the fuel/other composition of the advantage would be different.
 
User avatar
seahawk
Posts: 7556
Joined: Fri May 27, 2005 1:29 am

Re: Boeing 797 Discussion Thread - 2018

Mon Apr 09, 2018 12:08 pm

Do not forget the terminal. You have to consider waiting areas at the gate. What now is used for 3x180 passengers won´t hold 3x300. So, yes gates are connected to a certain plane size.
 
rheinwaldner
Posts: 1577
Joined: Wed Jan 02, 2008 4:58 pm

Re: Boeing 797 Discussion Thread - 2018

Mon Apr 09, 2018 12:32 pm

Matt6461 wrote:
Let's make this analytically clear. I will attempt to summarize your thesis; tell me whether I'm right.

Thesis: Planes with greater range cannot be more efficient than planes with less range.

If that is not a correct statement of your thesis, please explain in a clear manner that does not veer into questions.

It is a bit a far fetched interpretation of what I wrote, but under the assumption that the level of technology would be comparable, the thesis is correct IMO.

My thesis would include the competitiveness in relation to other aircraft:
"Mid- and long-range planes are not competitive against optimized aircraft from the range class below."

The whole idea of the MOM relies on this thesis to be true. If it is not true, the 787 would cover the MOM market sufficiently well.

To RJMAX:

We discussed whether the 797 could be competitive over short ranges (e.g. 1000nm).

Then you said:
RJMAZ wrote:
When you require a A321 or 737 to fly 3000+mm it will be taking off at or close to maximum takeoff weight. This means the initial cruise altitude is very low due to the small and overloaded wings. The fully loaded A321LR can not even reach 30,000 feet for the first few hours of its flight. This affects the entire average fuel burn for the trip.

The 797 will most definitely take off and go straight up to 35,000+ft on a 3000nm flight. The higher cruise altitude will improve fuel burn significantly. This payload range point is where the 797 will become the most efficient aircraft. It will extend up until the 787-8 takes over which would be potentially up around 4500nm.


I replied regarding this exact quote:
rheinwaldner wrote:
We were talking about 1000nm not 3000nm. You are moving the goalpost by the factor of three. 3000nm of course is within the RCR (range of competitive ranges) of the 797.


You then replied:
RJMAZ wrote:
I was covering all ranges from 0nm up to 5000nm when comparing the A321 to the 797.


So I ask, where is 0nm to 5000nm covered in the quoted text?
(try to stick to discussed topic and not change the parameter on the fly all the time. Since 10 posts or so I never discussed about anything else than the wrongfully claimed short range competitiveness of the 797).


RJMAZ wrote:
On a 1000nm flight the fuel burn per passenger will be on par. The better lift to drag ratio of the larger wing will allow slightly less thrust so it would cancel out any extra bulk of the 797. So at this range both are equal or competitive. This passes the "widebody with narrowbody economics" phrase in my opinion.

Above you said that the 797 would have the best CASM down to 2500nm. How can the 797 have on par fuel burn at 1000nm, but CASM would be second best below 2500nm, if large planes have much more benefits beside the fuel burn? To me it seems you just pull all your numbers as they suit your foregone conclusion.

If the 797 can be designed in a way that fuel burn is on par at 1000nm Boeing would better have designed the 787 that way to cover the 4000nm market too.

RJMAZ wrote:
The 797 will have a huge advantage at 3500nm but at what range did that advantage start to appear?

That's a matter of believe but not a matter of fact.

RJMAZ wrote:
A 1% fuel burn delta is the difference between the A320 and 737 families and the A330NEO and 787 families. So it can make a big difference on market share.

Sorry for being precise, but we were not talking about a fuel burn delta, but about a airport fee delta. As airport fees account for something like 6% in the total cost breakdown, a 1% delta in airport fees will make up a whopping difference of 0.06% of the total cost. Case closed.

And, even if the fuel burn delta between the mentioned aircraft families would really be 1%, the different market share would be result of other factors...
Many things are difficult, all things are possible!
 
User avatar
Matt6461
Posts: 2840
Joined: Wed Oct 16, 2013 9:36 pm

Re: Boeing 797 Discussion Thread - 2018

Mon Apr 09, 2018 1:21 pm

Rheinwaldner wrote:
It is a bit a far fetched interpretation of what I wrote, but under the assumption that the level of technology would be comparable, the thesis is correct IMO.

My thesis would include the competitiveness in relation to other aircraft:
"Mid- and long-range planes are not competitive against optimized aircraft from the range class below."


Now we're getting on the same page. Let me restate:

"Assuming equal technology level, longer-range planes are not competitive against optimized aircraft from a lower range class."

I mostly agree with this statement, with an additional qualifier:

"Assuming equal scale level and assuming... "

So I have two main critiques of your application of your thesis to the NMA/A321LR case:

1. You have so far evaded and/or ignored the impact of technology on this comparison. This will be ~2025 plane versus a revised 1988 plane - 37 years difference. More than between A320 and 707. The potential for tech impact is vast.

2. You have so far evaded and/or ignored the impact of scale economies on the comparison. Bigger planes generally have lower unit costs - flight crew alone is a significant delta vs. NB's.

Extending from (1), your analysis has so far failed to grapple with the following dynamic: advances in technology (SFC and L/D) continually reduce the magnitude of the "range penalty" while also decreasing the relative importance of fuel burn. Any comparison between historical planes of 4,000nm and 5,000nm range is not the right metric - it's comparisons of planes whose fuel fraction ratios at MTOW are similar to the fuel fraction ratio of NMA and A321LR. By 1980's standards, we're talking only ~500nm range differential.

...to repeat what I've said throughout, I'm only correcting your analytical framework - not necessarily your conclusions.
I'm now agnostic on the NMA; it depends on what the plane actually looks like.
Waiting for some projected performance figures is the only intellectually serious thing to do here; instead you're relying on simplistic, trite, superficial intuitions. You can do better.
 
RJMAZ
Posts: 1011
Joined: Sat Jul 09, 2016 2:54 am

Re: Boeing 797 Discussion Thread - 2018

Mon Apr 09, 2018 2:00 pm

rheinwaldner wrote:
We were talking about 1000nm not 3000nm. You are moving the goalpost by the factor of three. 3000nm of course is within the RCR (range of competitive ranges) of the 797.

I can't see any post where we were talking about 1000nm.

I mentioned that the efficiency drops off.
Where did we originally decide we were talking about 1000nm?

The first mention of range was by me at 3000+nm.


rheinwaldner wrote:
To me it seems you just pull all your numbers as they suit your foregone conclusion..
As Matt said I don't see any clear coherent thoughts in your post. You ask no direct questions. It is extremely frustrating and extremely time consuming going around in circles. You need to be much more direct with your argument.

The confusion might be because fuel efficiency is not a straight line.

For example the A321 might have a 2% fuel burn advantage at 500nm, a 1% advantage at 1000nm and become equal at 2000nm. The 797 then gains a 1% advantage at 3000nm.

As the 797 will have lower airport costs per passenger the 797 might win up to 500nm, but the superior fuel burn of the A321 at 500nm means it takes the lead as the range goes above 500mm. The 797 then takes back the lead at range approaches 2000nm.

The reason for this is the small wing of the A321 means it's fuel burn increases at a quicker rate than other aircraft as flying weight increases. On a 500nm flight the A321 would be light. It would go straight up to max cruise altitude so the 797 wouldn't have the initial cruise altitude advantage that it would have when the A321 gets heavier.

rheinwaldner wrote:
If the 797 can be designed in a way that fuel burn is on par at 1000nm Boeing would better have designed the 787 that way to cover the 4000nm market too..
Well no. The 797 will be a third gen carbon fibre design with aerodynamics from 2018. The A321 which is a metal plane with a tiny over worked wing, a wing designed 40 years ago. So it is easy for the 797 to match fuel burn down to 1000nm.

The 787 and 797 are both carbon and have modern aerodynamics. As you say:

"Mid and long range planes (787) are not competitive against optimized aircraft from the range class below (797)."

This obviously only applies if the aircraft are built with similar engine tech, similar materials and similar decade of wing aerodynamics. The A321NEO may has similar engine tech but has inferior materials and wing aerodynamics.



rheinwaldner wrote:
As airport fees account for something like 6% in the total cost breakdown, a 1% delta in airport fees will make up a whopping difference of 0.06% of the total cost. Case closed..

That depends on how short the flight is. They are a bigger percentage difference on a 1 hour than they are on a 10 hour.
Last edited by RJMAZ on Mon Apr 09, 2018 2:13 pm, edited 1 time in total.
 
rheinwaldner
Posts: 1577
Joined: Wed Jan 02, 2008 4:58 pm

Re: Boeing 797 Discussion Thread - 2018

Mon Apr 09, 2018 2:08 pm

Matt6461 wrote:
1. You have so far evaded and/or ignored the impact of technology on this comparison. This will be ~2025 plane versus a revised 1988 plane - 37 years difference. More than between A320 and 707. The potential for tech impact is vast.

2. You have so far evaded and/or ignored the impact of scale economies on the comparison. Bigger planes generally have lower unit costs - flight crew alone is a significant delta vs. NB's.

Extending from (1), your analysis has so far failed to grapple with the following dynamic: advances in technology (SFC and L/D) continually reduce the magnitude of the "range penalty" while also decreasing the relative importance of fuel burn. Any comparison between historical planes of 4,000nm and 5,000nm range is not the right metric - it's comparisons of planes whose fuel fraction ratios at MTOW are similar to the fuel fraction ratio of NMA and A321LR. By 1980's standards, we're talking only ~500nm range differential.

1) Technology impact:
-> Expected SFC difference of 2022 A322 vs a 2025 NMA: small enough that RJMAXs airport fee gap might come into the picture...
-> Expected L/D difference between the same two aircraft: small enough that inherent weight disadvantage of the beefed up 797 wont be overturned...

2) Size impact:
-> More than negated by 3) (see below). I am a fan of larger aircraft too. But 77Ws replacing 744s, 789s replacing 772ERs, A321s replacing 757s show that airlines put the focus more on efficiency than on the scale of economies. The A380 (which is on par regarding fuel burn) would sell much better if the size benefit would be as large as you say. Ask yourself the question, how popular it would be, if the US airlines would half the flight frequency in their networks and start using A300-type of aircraft instead of 737s.

But how about the next one? You forgot to consider your own requirement:
3) A larger plane must offer significantly improved efficiency per seat, otherwise airlines prefer the flexibility and lower risk (less seats to fill) of a smaller plane, flown at higher frequency if needed.
Many things are difficult, all things are possible!
 
User avatar
Matt6461
Posts: 2840
Joined: Wed Oct 16, 2013 9:36 pm

Re: Boeing 797 Discussion Thread - 2018

Mon Apr 09, 2018 2:25 pm

Rheinwaldner wrote:
But how about the next one? You forgot to consider your own requirement:
3) A larger plane must offer significantly improved efficiency per seat, otherwise airlines prefer the flexibility and lower risk (less seats to fill) of a smaller plane, flown at higher frequency if needed.


No I didn't. We were discussing efficiency. Efficiency means unit costs; capacity impacts both unit costs and unit revenues.
This is why conceptual clarity is essential: you must have a clear picture of the discussion in mind, otherwise you bring up irrelevant points that make things harder.

Rheinwaldner wrote:
1) Technology impact:
-> Expected SFC difference of 2022 A322 vs a 2025 NMA: small enough that RJMAXs airport fee gap might come into the picture...
-> Expected L/D difference between the same two aircraft: small enough that inherent weight disadvantage of the beefed up 797 wont be overturned...


Again, conceptual clarity: you didn't make any of these assertions in your past posts; you only asserted that longer range means lower efficiency.

Now that you've made your assertions I can evaluate them. I find them wanting.
Ultrafan should have ~15% lower SFC than PW1000/LEAP. L/D difference over A321 should be huge: A321 is underwinged.
Re "beefing up," with sufficient SFC and L/D differential NMA's fuel lift per pax could be equal to A321's. Therefore ZERO beefing up penalty versus A321. There would be a penalty versus a 2025 optimized shorthauler but nobody expects that plane to exist.

Re size impact: I don't find a coherent thought to respond to. Your question about A300's and frequencies again shifts the grounds of discussion from efficiency to revenue/profitability. That's a related discussion but for now let's keep that distinct and try to tackle the question before us. We can move from efficiency to profitability once we've clarified the efficiency picture.

EDIT: Now I notice you reference a 2022 A322 instead of 321. Once again you're shifting the grounds of debate sub silentio. You have maintained that no LR plane can beat a SR's efficiency, but now you want to use a better SR plane for the comparison.
...which wouldn't matter if the issue were simply SR v. LR. But it's not of course.
You appear to have conceded that it's not simply SR v. LR, but you haven't clarified that as part of your concession you're now giving yourself a better SR plane. Very frustrating.
 
parapente
Posts: 2877
Joined: Tue Mar 28, 2006 10:42 pm

Re: Boeing 797 Discussion Thread - 2018

Mon Apr 09, 2018 2:38 pm

Thanks for posting/re posting the latest JonO's words and pic's on the 797.Key quote.

The yet-to-be-launched NMA is slated to arrive in 2025. First with the base model, the NMA-6X (225 passengers at 5,000nm) and the NMA-7X (265 passengers at 4,500nm) two years later, according to two people familiar with Boeing’s planning today.

To me Boeing have been absolutly consistent with what they see as a 'Middle of market' aircaft.It isn't an A321LR nor is it a 778 - it is a MOM.
Of course it will overlap and compete at both edges of its performance profile both pax and range but it is a different aircaft.Different fuse size,different power requirements optimised for the job it will do best.
It's really quite a bold move imho.The a/c in this area (A300,310 B767,757) have effectively been out of production for circa a decade.And as the market as a whole expands and fragments there is every reason to suggest it will do well.After all non optimised aircraft in this area (A321LR/788) have/are selling well.If that growth trend is extrapolated forwards 20 years it could well be quite a tasty market.

Off topic.But if they do launch,clearly it puts back any 737 replacement by 10+ years.From a technological standpoint this may be very fortunate.We are hearing more and more about the increasing possibilities of hybrid electric aircaft.The technology is not quite there yet-especially battery technology.But if all reports are to be believed this is only 5-8 years away (solid metal batteries).Then all sorts of things become possible.A solid state magnesium (as opposed to lithium) battery will have x4 energy density and be far lighter than present batteries.
No it wont touch the energy densities of hydrocarbons but probably enough for hybrid use.Particularly as we are talking far shorter trips for such NB aircraft.
So imho the 797 timing happens to be right from this standpoint as well.
 
User avatar
seahawk
Posts: 7556
Joined: Fri May 27, 2005 1:29 am

Re: Boeing 797 Discussion Thread - 2018

Mon Apr 09, 2018 3:25 pm

I would rather think that the NSA will follow by 2030, as the 797 gives Boeing the production capabilities to redo the 737.
 
rheinwaldner
Posts: 1577
Joined: Wed Jan 02, 2008 4:58 pm

Re: Boeing 797 Discussion Thread - 2018

Mon Apr 09, 2018 3:57 pm

RJMAZ wrote:
rheinwaldner wrote:
We were talking about 1000nm not 3000nm. You are moving the goalpost by the factor of three. 3000nm of course is within the RCR (range of competitive ranges) of the 797.

I can't see any post where we were talking about 1000nm.

I mentioned that the efficiency drops off.
Where did we originally decide we were talking about 1000nm?

I am talking for many posts now about short-haul competitiveness of medium-range aircraft (and I used 1000nm just as a synonym for short-range). If that was not clear to you, I can understand why you were talking about many other things. I fully agree that the 797 will rule at 3000nm. It was just not my topic.

I just wonder whether my posts really were so hard to understand. Maybe some other users, who have read my posts, can give me feedback whether the topic "short-haul competitiveness of medium-range aircraft" was made clear enough or not...

Matt6461 wrote:
Rheinwaldner wrote:
But how about the next one? You forgot to consider your own requirement:
3) A larger plane must offer significantly improved efficiency per seat, otherwise airlines prefer the flexibility and lower risk (less seats to fill) of a smaller plane, flown at higher frequency if needed.


No I didn't. We were discussing efficiency. Efficiency means unit costs; capacity impacts both unit costs and unit revenues.
This is why conceptual clarity is essential: you must have a clear picture of the discussion in mind, otherwise you bring up irrelevant points that make things harder.

My dear friend, the thesis, to which you mostly agreed (it is in fact common sense), did not talk about efficiency but about competitiveness. So no wonder you miss conceptual clarity so dearly if you thought that I was talking about efficiency.

Competitiveness includes all. Frequency, capacity, RASM. It gives the full picture.

Matt6461 wrote:
Again, conceptual clarity: you didn't make any of these assertions in your past posts; you only asserted that longer range means lower efficiency.

Look through the posts and find the point, from where we discussed the application of the thesis in the NMA/A321 case. Beside your twist that you suddenly were talking about efficiency instead of competitiveness, I simply replied in the context that you have defined in the quoted post. It is not my problem if you loose conceptual clarity after I reply in line with the question that you have raised. So please read my post once more under the idea, that we apply the thesis to the A321/NMA situation (I have only taken the freedom to include the A322, as its existence will be extremely probable once the 797 is born).
Many things are difficult, all things are possible!
 
User avatar
Revelation
Topic Author
Posts: 19136
Joined: Wed Feb 09, 2005 9:37 pm

Re: Boeing 797 Discussion Thread - 2018

Mon Apr 09, 2018 4:52 pm

parapente wrote:
Thanks for posting/re posting the latest JonO's words and pic's on the 797. Key quote.

The yet-to-be-launched NMA is slated to arrive in 2025. First with the base model, the NMA-6X (225 passengers at 5,000nm) and the NMA-7X (265 passengers at 4,500nm) two years later, according to two people familiar with Boeing’s planning today.

To me Boeing have been absolutely consistent with what they see as a 'Middle of market' aircraft. It isn't an A321LR nor is it a 788 - it is a MOM.
Of course it will overlap and compete at both edges of its performance profile both pax and range but it is a different aircraft. Different fuse size, different power requirements optimised for the job it will do best.

I'm with you.

I think we're down to two possibilities:
a) Boeing will be producing an all-new ovoid twin-aisle NMA with the general characteristics above
b) Boeing has run a masterful disinformation campaign that has fooled the CEOs of DL, QF, UA, et al and they're actually making 788-lite
c) Boeing can't convince itself/customers/BoD that there's a business case here, move on, nothing to see here

Personally, I'm thinking (a) is the most likely outcome.
Wake up to find out that you are the eyes of the world
The heart has it's beaches, it's homeland and thoughts of it's own
Wake now, discover that you are the song that the morning brings
The heart has it's seasons, it's evenings and songs of it's own
 
User avatar
QuarkFly
Posts: 326
Joined: Mon Aug 15, 2016 4:20 pm

Re: Boeing 797 Discussion Thread - 2018

Mon Apr 09, 2018 5:41 pm

Interesting that AA just ordered a bunch of 788's -- a model that seemed moribund and close to the end of its production run. But it does show if you want a mid-market passenger count (< 250) with significant LD3 cargo, there is an option (probably not A338 anymore)...Which makes me think that if NMA is launched by B -- it will not support the Asian carriers' desire for lots of belly cargo. You want that -- B will happily still sell you a 788. NMA is primarily a people mover.

Wonder if a weight limited 788 will ever be produced? -- An on-paper reduction to about 175 ton MTOW -- to reduce airport charges. However the A330-Regional apparently never did well.

Way too much discussion here about NMA vs. a A321LR / A322 ...The NMA sounds like it Is a risky strategy of trying to create a new market above the A321...These massive narrow-body backlogs at A and B are perhaps showing that single-isle's are being shoved into markets where they don't belong. Two years ago I flew on a 739 from S. Korea ICN to BKK, Yuk !!...I also really hate transatlantic on a 757...and A321 or 738 will be worse.

I would hope that a NMA small-twin would save us from a mid-range single-isle nightmare...but I fear the LCC mentality will move into the mid-to-long range, trans-Atlantic and intra-Asia routes -- on NEO's and Max. So I am hoping for a NMA success but I am not confident.
Always take the Red Eye if possible

Popular Searches On Airliners.net

Top Photos of Last:   24 Hours  •  48 Hours  •  7 Days  •  30 Days  •  180 Days  •  365 Days  •  All Time

Military Aircraft Every type from fighters to helicopters from air forces around the globe

Classic Airliners Props and jets from the good old days

Flight Decks Views from inside the cockpit

Aircraft Cabins Passenger cabin shots showing seat arrangements as well as cargo aircraft interior

Cargo Aircraft Pictures of great freighter aircraft

Government Aircraft Aircraft flying government officials

Helicopters Our large helicopter section. Both military and civil versions

Blimps / Airships Everything from the Goodyear blimp to the Zeppelin

Night Photos Beautiful shots taken while the sun is below the horizon

Accidents Accident, incident and crash related photos

Air to Air Photos taken by airborne photographers of airborne aircraft

Special Paint Schemes Aircraft painted in beautiful and original liveries

Airport Overviews Airport overviews from the air or ground

Tails and Winglets Tail and Winglet closeups with beautiful airline logos