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RJMAZ
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Re: Boeing 797 Discussion Thread - 2018

Thu Oct 18, 2018 2:08 am

flipdewaf wrote:
seabosdca wrote:
For this aircraft, an oval fuselage isn't an "exotic" feature to leave out when price negotiations get down to brass tacks. It's the core of the business case. Take it away and you have a 767 MAX with pretty wings, which Boeing knows perfectly well has no hope of competing on operating economics with the A321neo.
.

So the question is...
Does the reduced lift independent drag outweigh both the increase in induced drag due to increased fuselage weight and the reduced versatility of a smaller cargo compartment?

Fred

It would definitely be worth the going oval.

Medium to long thin routes usually have very little demand for cargo other than passenger bags. It is highly likely the 797 will not be built for cargo.

A 787-8 taking off with maximum payload weight can only fill its fuel tanks to approximately 65% capacity before hitting MTOW. The 787-8 would struggle to fly between two airports 5000nm apart which is well inside the MOM range window. The 797 could fly that same route but with passengers and bags only in a 3 class cabin.

On a 4000-5000nm MOM range route you can use the 787-8 if you need cargo or the 797 if you dont need cargo. They would compliment eachother nicely, it would be silly for Boeing to build the 797 as a big cargo mover when you have the 787. You would lose efficiency by adding cargo volume to the 797.

Also regarding structural efficiency and weight of an oval: The fineness ratio usually takes the width to length of an aircraft. The 797 of reduced height cross section might have a normal finesness ratio when viewed from the side but a short and stubby A310 fineness ratio when viewed from the top. As the oval would not be as strong when it comes to bending Boeing can simply make it stubby. That is why i think it will definitely be a tight 8ab cross section with a reduced height lower lobe.
 
grbauc
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Re: TUI wants the 797

Thu Oct 18, 2018 2:15 am

Revelation wrote:
TTailedTiger wrote:
B777LRF wrote:
Reading the quote you posted, it states rather clearly that Boeing is presenting the airlines with a blank sheet of paper, asking them what they'd like. That's pretty much as far removed from payload/range charts, performance numbers, timelines and what have you, as it gets. And the bit about 'scheduled to enter service in 2025' is yet more marketing fluff; and as anyone who's been following aviation for the last decade will testify, you don't go from a blank piece of paper to 'enter service' in 7 years. That's before we even get to the crux of the matter, which is lack of a suitable engine. RR are knee-deep in doo-doo with the Trent which is bound to the delay the 'superfan'; PW are in the same situation with the GTF and are not in a position to up-gauge that engine any time soon, and GE doesn't even remotely have something in the pipeline. Which means, at present the only propulsion on offer is, indeed, marketing hot air.

PS
I too have been on a team buying aircraft from Boeing.


So then you don't believe Boeing will receive any engine proposals that are due soon?

Especially since they've already gotten a first set of proposals from all three engine vendors?

It's not hard to see CFM propose a scaled up LEAP with the CMC hot section components from GE9x that Lightsaber tells us are as much of a game changer as GTF is.

RR actually is on schedule with SuperFan, see our discussion earlier in this thread.

Agree...


If anyone is a non-starter, I'd have to say its PW. Their track record was bad before GTF and now it's atrocious.

PS: Blank piece of paper? B777LRF has gone from off target to ridiculous.



Spot on!!!
 
grbauc
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Re: Boeing 797 Discussion Thread - 2018

Thu Oct 18, 2018 2:29 am

B777LRF wrote:
musman9853 wrote:
marcelh wrote:
Do we have a reliable engine?



P&W,RR,and GE/CFM have all submitted engine proposals. IMO GE/CFM is a lock, but i'm not sure rr or p&w gets the other option. my moneys on rr tho


'Proposals', well, according to several sources GE are not sure there's a business making it worth their while. RR's SuperFan is still an R&D project, and PW need to get their shyte together before anyone will take them seriously.

What Boeing asked for is an engine weighing x amount of kilograms, producing x amount of thrust with a TSFC in this or that ballpark. And the engine OEMs submitted a paper saying 'sure, we can do that'. That's about as fluffy as Boeing's non-solid 797 'proposals'.


Plenty of proof if you want it.. this project is and has been moving forward. I'm guessing your just being obtuse.
 
grbauc
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Re: Boeing 797 Discussion Thread - 2018

Thu Oct 18, 2018 3:22 am

TTailedTiger wrote:
I am excited with the prospect of traditionally narrowbody only airlines ordering the 797 for upguaging current capacity as well as going into new city pairs. I could definitely see airlines like Alaska and Copa ordering the 797 to expand their operations now that a smaller and highly efficient widebody is available. Perhaps Southwest would be interested in it for Hawaii and South America. But I doubt we would ever see them start service to Europe or Asia. Ryanair could also be a good candidate. I also think it might make sense for GOL. It would be a nice fit for JetBlue but they are attached at the hip to Airbus.


Yes this could be very interesting in opening up new opportunities to some airlines.
 
mffoda
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Re: Boeing 797 Discussion Thread - 2018

Thu Oct 18, 2018 3:55 am

Another article to add to the discussion... :twocents:

https://thewest.com.au/news/aviation/bo ... b88994564z
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adv40624
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Re: Boeing 797 Discussion Thread - 2018

Thu Oct 18, 2018 4:17 am

After reading the article above, I wonder if the airlines will leave the 797 at 7 across seating as Boeing is proposing according to the article, or add another seat and make it 8 across cattle car seating? The 787 was pitched to be 8 across and United took care of that by making their planes 9 across and most every airline followed except for JAL. The 787 is an excellent aircraft, but it was never designed to be 9 across and you can feel it sitting in economy. Most airlines that fly the 777 have followed each other and converted economy into 10 across seating up from 9 that Boeing developed the plane to be. Thank you Delta for leaving it 3-3-3. Some cattle car charter airlines have put 8 across seating in their 767 aircraft as well. It is going to be interesting to follow the development of the 797 and see what the seat count turns out to be.
 
JHwk
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Re: Boeing 797 Discussion Thread - 2018

Thu Oct 18, 2018 4:19 am

mffoda wrote:
Another article to add to the discussion... :twocents:

https://thewest.com.au/news/aviation/bo ... b88994564z


Makes me think it will be a narrow 8 abreast for sure!
 
flipdewaf
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Re: Boeing 797 Discussion Thread - 2018

Thu Oct 18, 2018 8:28 am

RJMAZ wrote:
flipdewaf wrote:
seabosdca wrote:
For this aircraft, an oval fuselage isn't an "exotic" feature to leave out when price negotiations get down to brass tacks. It's the core of the business case. Take it away and you have a 767 MAX with pretty wings, which Boeing knows perfectly well has no hope of competing on operating economics with the A321neo.
.

So the question is...
Does the reduced lift independent drag outweigh both the increase in induced drag due to increased fuselage weight and the reduced versatility of a smaller cargo compartment?

Fred

It would definitely be worth the going oval.

Medium to long thin routes usually have very little demand for cargo other than passenger bags. It is highly likely the 797 will not be built for cargo.

A 787-8 taking off with maximum payload weight can only fill its fuel tanks to approximately 65% capacity before hitting MTOW. The 787-8 would struggle to fly between two airports 5000nm apart which is well inside the MOM range window. The 797 could fly that same route but with passengers and bags only in a 3 class cabin.

On a 4000-5000nm MOM range route you can use the 787-8 if you need cargo or the 797 if you dont need cargo. They would compliment each other nicely, it would be silly for Boeing to build the 797 as a big cargo mover when you have the 787. You would lose efficiency by adding cargo volume to the 797.

Also regarding structural efficiency and weight of an oval: The fineness ratio usually takes the width to length of an aircraft. The 797 of reduced height cross section might have a normal finesness ratio when viewed from the side but a short and stubby A310 fineness ratio when viewed from the top. As the oval would not be as strong when it comes to bending Boeing can simply make it stubby. That is why i think it will definitely be a tight 8ab cross section with a reduced height lower lobe.

I wouldn't disagree with anything you have said there apart from the first part
It would definitely be worth the going oval.
because the question is whether going oval benefits the whole scenario.

Making it stubby = Nothing about the oval
Range and fuel in tanks = Nothing about making it oval

So the question remains wholly unanswered: Does the reduced lift independent drag outweigh both the increase in induced drag due to increased fuselage weight and the reduced versatility of a smaller cargo compartment?

You have characterised the market well and I accept that there is little need for cargo on the particular market the 797 is aimed at. The issue isnt with bending it is with pressurisation and the increased weight which is not being taken account of.

Fred
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Re: Boeing 797 Discussion Thread - 2018

Thu Oct 18, 2018 12:07 pm

AvWeek: Boeing's New Midsize Airplane Will Happen, Say Analysts is registering a shift in sentiments:

Boeing has pushed back an announcement over pursuing the New Midsize Airplane (NMA) until sometime in 2019, but increasingly, financial analysts are seeing the new aircraft as a fait accompli.

It goes on to say:

:arrow: “Airline views on this Boeing concept appeared increasingly positive to us, with the design parameters firming”
:arrow: "Airlines appear to now be more interested in the NMA relative to current Airbus or Boeing products"
:arrow: "This could lead to a more aggressive response by Airbus"
:arrow: Expanding Boeing Global Services is seen as smoothing out development cycles even if it raises interim risk levels
:arrow: NMA provides a proper response to A321
:arrow: NMA provides a lower risk for the eventual 737 replacement
:arrow: 50% of suppliers surveyed see a 2019 NMA release whereas 10% do not
:arrow: Only 20% of suppliers say they are not in discussions with Boeing on NMA

2019 should be an interesting year.
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william
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Re: Boeing 797 Discussion Thread - 2018

Thu Oct 18, 2018 1:28 pm

mffoda wrote:
Another article to add to the discussion... :twocents:

https://thewest.com.au/news/aviation/bo ... b88994564z


Cute, using a pic of the almost launched 7J7 from the "80s". A plane that would have had a GTF like "Superfan"engine by the IAE consortium.

What's old is new again.

The 797 is not the engineering leap some make it out to be. Boeing has been working on these same concepts for years. The leap is trying to build it cheaply with fat profit margins.
 
morrisond
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Re: Boeing 797 Discussion Thread - 2018

Thu Oct 18, 2018 1:42 pm

RJMAZ wrote:
flipdewaf wrote:
seabosdca wrote:
For this aircraft, an oval fuselage isn't an "exotic" feature to leave out when price negotiations get down to brass tacks. It's the core of the business case. Take it away and you have a 767 MAX with pretty wings, which Boeing knows perfectly well has no hope of competing on operating economics with the A321neo.
.

So the question is...
Does the reduced lift independent drag outweigh both the increase in induced drag due to increased fuselage weight and the reduced versatility of a smaller cargo compartment?

Fred

It would definitely be worth the going oval.

Medium to long thin routes usually have very little demand for cargo other than passenger bags. It is highly likely the 797 will not be built for cargo.

A 787-8 taking off with maximum payload weight can only fill its fuel tanks to approximately 65% capacity before hitting MTOW. The 787-8 would struggle to fly between two airports 5000nm apart which is well inside the MOM range window. The 797 could fly that same route but with passengers and bags only in a 3 class cabin.

On a 4000-5000nm MOM range route you can use the 787-8 if you need cargo or the 797 if you dont need cargo. They would compliment eachother nicely, it would be silly for Boeing to build the 797 as a big cargo mover when you have the 787. You would lose efficiency by adding cargo volume to the 797.

Also regarding structural efficiency and weight of an oval: The fineness ratio usually takes the width to length of an aircraft. The 797 of reduced height cross section might have a normal finesness ratio when viewed from the side but a short and stubby A310 fineness ratio when viewed from the top. As the oval would not be as strong when it comes to bending Boeing can simply make it stubby. That is why i think it will definitely be a tight 8ab cross section with a reduced height lower lobe.


I still say it will be a tight 7W with small lower lobe so they can reuse the cross section and nose on NSA (albeit with different wing, tail and wingbox most likely). It just makes too much financial sense to not do this and then have a lot of commonality between NMA and NSA.
 
parapente
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Re: Boeing 797 Discussion Thread - 2018

Thu Oct 18, 2018 2:08 pm

Commonality between NMA and NSA?
I am not sure it's not an NSA in disguise!
They are talking 228 pax and 4,500 nm.Well that's a one class 240-250 seater which is what the A321neo is and the range is the same give or take what the A321XLR proposal is.
The difference is two fold.It can take cargo at this range if needs be and it's turnaround time will be much faster (It will no doubt fly and climb faster too).
Also passengers will prefer its (twin aisle) space internally as they do the 767.Perhaps this is why stretching the A321neo (322) has been taken off the table?
 
osupoke07
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Re: Boeing 797 Discussion Thread - 2018

Thu Oct 18, 2018 2:18 pm

morrisond wrote:
RJMAZ wrote:
flipdewaf wrote:
So the question is...
Does the reduced lift independent drag outweigh both the increase in induced drag due to increased fuselage weight and the reduced versatility of a smaller cargo compartment?

Fred

It would definitely be worth the going oval.

Medium to long thin routes usually have very little demand for cargo other than passenger bags. It is highly likely the 797 will not be built for cargo.

A 787-8 taking off with maximum payload weight can only fill its fuel tanks to approximately 65% capacity before hitting MTOW. The 787-8 would struggle to fly between two airports 5000nm apart which is well inside the MOM range window. The 797 could fly that same route but with passengers and bags only in a 3 class cabin.

On a 4000-5000nm MOM range route you can use the 787-8 if you need cargo or the 797 if you dont need cargo. They would compliment eachother nicely, it would be silly for Boeing to build the 797 as a big cargo mover when you have the 787. You would lose efficiency by adding cargo volume to the 797.

Also regarding structural efficiency and weight of an oval: The fineness ratio usually takes the width to length of an aircraft. The 797 of reduced height cross section might have a normal finesness ratio when viewed from the side but a short and stubby A310 fineness ratio when viewed from the top. As the oval would not be as strong when it comes to bending Boeing can simply make it stubby. That is why i think it will definitely be a tight 8ab cross section with a reduced height lower lobe.


I still say it will be a tight 7W with small lower lobe so they can reuse the cross section and nose on NSA (albeit with different wing, tail and wingbox most likely). It just makes too much financial sense to not do this and then have a lot of commonality between NMA and NSA.


My wild speculation is that the 797 and NSA will share a common nose and flight deck, but NSA will get a narrower fuselage for 6 abreast seating. My guess is they'll also have a common type rating. The NSA could also be branded under the 797 family name, taking up either the 8/9 designations to replace the 737 model numbers or using 1/2/3.
MD82, MD83, MD88, B717, B732, B733, B735, B737, B738, B739, B752, B763, B77W, CR2, CR7, CR9, A320, A321
 
musman9853
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Re: Boeing 797 Discussion Thread - 2018

Thu Oct 18, 2018 2:26 pm

Revelation wrote:
AvWeek: Boeing's New Midsize Airplane Will Happen, Say Analysts is registering a shift in sentiments:

Boeing has pushed back an announcement over pursuing the New Midsize Airplane (NMA) until sometime in 2019, but increasingly, financial analysts are seeing the new aircraft as a fait accompli.

It goes on to say:

:arrow: “Airline views on this Boeing concept appeared increasingly positive to us, with the design parameters firming”
:arrow: "Airlines appear to now be more interested in the NMA relative to current Airbus or Boeing products"
:arrow: "This could lead to a more aggressive response by Airbus"
:arrow: Expanding Boeing Global Services is seen as smoothing out development cycles even if it raises interim risk levels
:arrow: NMA provides a proper response to A321
:arrow: NMA provides a lower risk for the eventual 737 replacement
:arrow: 50% of suppliers surveyed see a 2019 NMA release whereas 10% do not
:arrow: Only 20% of suppliers say they are not in discussions with Boeing on NMA

2019 should be an interesting year.




seems almost a forgone conclusion that the 797 is going ahead, much to the chagrin of those who say it's a paper airplane.
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Stitch
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Re: Boeing 797 Discussion Thread - 2018

Thu Oct 18, 2018 2:36 pm

A "tight 8" means a 767 cross section at minimum and while this plane does seem to be designed around being a true 767 successor, the world's majors all appear to have set a minimum width of 17 inches / 43 centimeters so I expect that even if Boeing does with a 767 cross-section in the main cabin, you will see 2+3+2 by almost all operators.
 
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Re: Boeing 797 Discussion Thread - 2018

Thu Oct 18, 2018 2:45 pm

16,5 will work for economy minus.
 
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Stitch
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Re: Boeing 797 Discussion Thread - 2018

Thu Oct 18, 2018 3:35 pm

seahawk wrote:
16,5 will work for economy minus.


If it did, we'd see 767s with an 8-abreast section of the cabin and A330s, A340s and A350s with a 10-abreast section of the cabin from the worldwide majors.
 
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seahawk
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Re: Boeing 797 Discussion Thread - 2018

Thu Oct 18, 2018 3:45 pm

I can easily see Boeing trading seat width for the comfort of an extra aisle. And if the pre-launch focus links passenger comfort to the volume of overhead bins, I am always sceptical. So yes, I would not be surprised to see them go below 17".
 
skystar767
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Re: Boeing 797 Discussion Thread - 2018

Thu Oct 18, 2018 4:04 pm

I don’t think this plane should be a wide body. A narrow body would be much better for Boeing. It would replace the 757 which most airlines around the world liked. The 737 max too low the 787 too big. I thing the 797 narrow body would give the A321lr a run for its money.
 
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Re: Boeing 797 Discussion Thread - 2018

Thu Oct 18, 2018 4:34 pm

skystar767 wrote:
I don’t think this plane should be a wide body. A narrow body would be much better for Boeing. It would replace the 757 which most airlines around the world liked. The 737 max too low the 787 too big. I thing the 797 narrow body would give the A321lr a run for its money.

Sounds like you've never been in the last row of an A321 or 757-300 waiting for 200+ pax in front of you to deplane...
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Stitch
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Re: Boeing 797 Discussion Thread - 2018

Thu Oct 18, 2018 4:50 pm

seahawk wrote:
I can easily see Boeing trading seat width for the comfort of an extra aisle. And if the pre-launch focus links passenger comfort to the volume of overhead bins, I am always sceptical. So yes, I would not be surprised to see them go below 17".


Boeing would only trade it if airlines demanded it and I don't seem them doing so because otherwise we would have 8-abreast 767s, 9-abreast A330s and 10-abreast A350s as the "normal" configuration.
 
iamlucky13
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Re: Boeing 797 Discussion Thread - 2018

Thu Oct 18, 2018 5:05 pm

Revelation wrote:
skystar767 wrote:
I don’t think this plane should be a wide body. A narrow body would be much better for Boeing. It would replace the 757 which most airlines around the world liked. The 737 max too low the 787 too big. I thing the 797 narrow body would give the A321lr a run for its money.

Sounds like you've never been in the last row of an A321 or 757-300 waiting for 200+ pax in front of you to deplane...


To spin this from an airline standpoint: 270 seats, at the US domestic average RASM of $0.12, means lost revenue potential of roughly $200 per minute of unnecessary time spent unloading. Of course, that revenue potential is only realized if you can actually gain extra utilization from it, but there is still a non-trivial value for airlines to pursue from faster turn times.

Shaving 10 minutes off the load and unload process could work out to ~1-2% worth of revenue gain, not counting any potential for higher ticket prices if passengers have a preference for airlines operating small twin-aisle versus long single-aisles.
 
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Re: Boeing 797 Discussion Thread - 2018

Thu Oct 18, 2018 5:18 pm

seahawk wrote:
16,5 will work for economy minus.


Assuming identical aisle size for a widebody, that would mean designing the plane for almost 19" 7-abreast seating. That seems like an awkard position that may suit ULCC's well, and be a perk for mainstream airlines offering premium economy, but unlikely to resonate strongly with the majority of the market in economy.
 
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keesje
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Re: Boeing 797 Discussion Thread - 2018

Thu Oct 18, 2018 5:33 pm

I would prefer single aisles if seat width, aisle width and available luggage space is bigger.
"Never mistake motion for action." Ernest Hemingway
 
iamlucky13
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Re: Boeing 797 Discussion Thread - 2018

Thu Oct 18, 2018 5:34 pm

flipdewaf wrote:
So the question remains wholly unanswered: Does the reduced lift independent drag outweigh both the increase in induced drag due to increased fuselage weight and the reduced versatility of a smaller cargo compartment?

You have characterised the market well and I accept that there is little need for cargo on the particular market the 797 is aimed at. The issue isnt with bending it is with pressurisation and the increased weight which is not being taken account of.


Is the weight increased? This is not an easy question to answer. The frames and/or floor beams do have to be stronger in an ovalized fuselage, but the frame and skin circumference also decreases.

If I remember right, RJMAZ has been arguing in favor of a flattened double-bubble design. This still puts the floor beams in compression, and compromises cabin width at shoulder height, but I think is more favorable to the frame loading than an elliptical design.
 
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Re: Boeing 797 Discussion Thread - 2018

Thu Oct 18, 2018 5:48 pm

Stitch wrote:
seahawk wrote:
I can easily see Boeing trading seat width for the comfort of an extra aisle. And if the pre-launch focus links passenger comfort to the volume of overhead bins, I am always sceptical. So yes, I would not be surprised to see them go below 17".


Boeing would only trade it if airlines demanded it and I don't seem them doing so because otherwise we would have 8-abreast 767s, 9-abreast A330s and 10-abreast A350s as the "normal" configuration.


We do not know what the airlines demand. maybe they demand single aisle cost levels and then every inch matters. Or it is 17" with a 15" aisle which airlines might turn into 16.5" with a 17" aisle. I am not saying this is certain but i would also not rule that out.
 
RJMAZ
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Re: Boeing 797 Discussion Thread - 2018

Thu Oct 18, 2018 10:29 pm

Stitch wrote:
A "tight 8" means a 767 cross section at minimum and while this plane does seem to be designed around being a true 767 successor, the world's majors all appear to have set a minimum width of 17 inches / 43 centimeters so I expect that even if Boeing does with a 767 cross-section in the main cabin, you will see 2+3+2 by almost all operators.

That is not true. The 797 would have a much smaller cross section than the 767.

The 767 in 8 abreast uses 16.4" seats.

I predict the 797 will have a cabin 6" wider to allow standard 17" seats in 8ab.

The 767 fuselage is 5.03m wide but 5.41m tall.
The A330 fuselage is 5.64m circular.
The 797 I estimate to be 5.18m wide but only 4.5m tall. That is only 36cm taller than the A321.

Cross section area
A330 - 250,000 cm2
767 - 214,000 cm2
797 - 185,000 cm2
A321 - 129,000 cm2

The 767 wastes a lot of area to fit the LD2's with increased height.

The 767 is 26% less area than the A330 and 13% less area than the 767.

Cross section area per passenger would be a good metric for efficiency. Assuming 8ab and 7ab for the A330 and 767.

A330 - 31,250 cm2 per seat
767 - 30,570 cm2 per seat
797 - 23,125cm2 per seat
A321 - 21,500cm2 per seat

So a tight 8ab double bubble reduced height fuselage with LD3-45's height containers that are maybe a foot or two wider.
 
mzlin
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Re: Boeing 797 Discussion Thread - 2018

Thu Oct 18, 2018 10:33 pm

RJMAZ wrote:
The 767 is 26% less area than the A330 and 13% less area than the 767.

Cross section area per passenger would be a good metric for efficiency. Assuming 8ab and 7ab for the A330 and 767.

A330 - 31,250 cm2 per seat
767 - 30,570 cm2 per seat
797 - 23,125cm2 per seat
A321 - 21,500cm2 per seat

So a tight 8ab double bubble reduced height fuselage with LD3-45's height containers that are maybe a foot or two wider.


Thanks for the estimates; nice to have some numbers.

I believe there is a typo in the sentence "The 767 is 26% less area than the A330 and 13% less area than the 767."

For the area/seat calculations, for the 797, are you assuming 7ab or 8ab?
 
RJMAZ
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Re: Boeing 797 Discussion Thread - 2018

Thu Oct 18, 2018 11:24 pm

That is 8ab for the 797 with 17" seats. Cabin width is approximately half way between the 767 and A330.

Container wise. I would call the new custom container the LD8-45. Basically two 767 LD2 containers joined together but the height reduced from 64" to 45".
 
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keesje
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Re: Boeing 797 Discussion Thread - 2018

Thu Oct 18, 2018 11:53 pm

Average cabin width (without 20 inch aisle(s)) at shoulderheight per passenger would have my preference. Sidewall shape, armrest number/ width, aislewidth give too much opportunity for creativity / perception management with seat(bottom, cushion)width.
"Never mistake motion for action." Ernest Hemingway
 
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lightsaber
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Re: Boeing 797 Discussion Thread - 2018

Fri Oct 19, 2018 12:04 am

RJMAZ wrote:
Stitch wrote:
A "tight 8" means a 767 cross section at minimum and while this plane does seem to be designed around being a true 767 successor, the world's majors all appear to have set a minimum width of 17 inches / 43 centimeters so I expect that even if Boeing does with a 767 cross-section in the main cabin, you will see 2+3+2 by almost all operators.

That is not true. The 797 would have a much smaller cross section than the 767.

The 767 in 8 abreast uses 16.4" seats.

I predict the 797 will have a cabin 6" wider to allow standard 17" seats in 8ab.

The 767 fuselage is 5.03m wide but 5.41m tall.
The A330 fuselage is 5.64m circular.
The 797 I estimate to be 5.18m wide but only 4.5m tall. That is only 36cm taller than the A321.

Cross section area
A330 - 250,000 cm2
767 - 214,000 cm2
797 - 185,000 cm2
A321 - 129,000 cm2

The 767 wastes a lot of area to fit the LD2's with increased height.

The 767 is 26% less area than the A330 and 13% less area than the 767.

Cross section area per passenger would be a good metric for efficiency. Assuming 8ab and 7ab for the A330 and 767.

A330 - 31,250 cm2 per seat
767 - 30,570 cm2 per seat
797 - 23,125cm2 per seat
A321 - 21,500cm2 per seat

So a tight 8ab double bubble reduced height fuselage with LD3-45's height containers that are maybe a foot or two wider.

Your cross sectional area per passenger is a great metric. It really shows the cost of the widebody cross section and how the 797 could minimize that cost.

I'd be curious if you did the numbers for:
C-series
A380
777
E-jets

Thanks in advance,
Lightsaber
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Re: Boeing 797 Discussion Thread - 2018

Fri Oct 19, 2018 12:17 am

Did I miss something about cabin width? Why are we quoting numbers? Did one of the articles actually give the elusive airplane dimensions? I just saw two class seat counts.
 
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Re: Boeing 797 Discussion Thread - 2018

Fri Oct 19, 2018 12:43 am

keesje wrote:
Average cabin width (without 20 inch aisle(s)) at shoulderheight per passenger would have my preference. Sidewall shape, armrest number/ width, aislewidth give too much opportunity for creativity / perception management with seat(bottom, cushion)width.

I disgree. Aisle width can and should vary.

A 2-3-2 economy cabin can use narrower aisles than say 3-5-3 economy cabin. To use the same width aisle on both is unfair against narrower aircraft.

Also a shorter aircraft can use narrower aisles. The long 757-300 desperately needed a wider aisle but that same aisle width works fine on the shorter 737-8.

A tight 8ab cabin on the 797 would have a fairly short fuselge length based on the published capacity numbers. Cabin length would probably be similar to a 737-10. As each aisle is effectively serving a 2-2 seating cabin it can be much narrower.

It would not surprise me if the 797 in 8ab had two 16" aisles. That is still more aisle area per passenger than the A320 family. You might have to walk slower down the aisle but having two aisles completely offsets this.
 
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Re: Boeing 797 Discussion Thread - 2018

Fri Oct 19, 2018 12:48 am

RJMAZ wrote:
keesje wrote:
Average cabin width (without 20 inch aisle(s)) at shoulderheight per passenger would have my preference. Sidewall shape, armrest number/ width, aislewidth give too much opportunity for creativity / perception management with seat(bottom, cushion)width.

I disgree. Aisle width can and should vary.

A 2-3-2 economy cabin can use narrower aisles than say 3-5-3 economy cabin. To use the same width aisle on both is unfair against narrower aircraft.

Also a shorter aircraft can use narrower aisles. The long 757-300 desperately needed a wider aisle but that same aisle width works fine on the shorter 737-8.

A tight 8ab cabin on the 797 would have a fairly short fuselge length based on the published capacity numbers. Cabin length would probably be similar to a 737-10. As each aisle is effectively serving a 2-2 seating cabin it can be much narrower.

It would not surprise me if the 797 in 8ab had two 16" aisles. That is still more aisle area per passenger than the A320 family. You might have to walk slower down the aisle but having two aisles completely offsets this.

First excellent post. However, I'm recalling a 18" minimum width for evacuation paths. But I'm going from memory.

Lightsaber
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Re: Boeing 797 Discussion Thread - 2018

Fri Oct 19, 2018 1:17 am

lightsaber wrote:
First excellent post. However, I'm recalling a 18" minimum width for evacuation paths. But I'm going from memory.

Lightsaber

I remember checking and it is 15" minimum so we are all good.


Here are the cabin cross sections accurate to nearest 1%
Ejet - 80,000 cm2
A220 - 108,000 cm2
737 - 120,000 cm2
A320 - 129,000 cm2
797 estimate - 185,000 cm2
767 - 214,000 cm2
A330 - 250,000 cm2
787 - 268,000 cm2
A350 - 285,000 cm2
777 - 302,000 cm2
A380 - 473,000 cm2

Here are the area per passenger:
Ejet (4) - 20,000 cm2
A220 (5) - 27,000 cm2
737 (6) - 20,000 cm2
A320 (6) - 21,500 cm2
797 (8) estimate - 23,125 cm2
767 (7) - 30,500 cm2
A330 (8) - 31,250 cm2
787 (9) - 29,700 cm2
A350 (9) - 31,600 cm2
777 (10) - 30,200 cm2
A380 (18) - 26,200 cm2

Obviously these dont take into account the aisle width. Also the Airbus models have seats half an inch wider than the Boeing models listed. They are all very close with a few exceptions.

The A380 is really well packaged with very little wasted crown space. The C series is far too big for a 5 breast cabin. Explins the poor sales, all that wizz bang tech would struggle to make up for that.

The 737 would have less drag than the A320 which is why it can remain competitive despite being limited on engine fan diameter.
 
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Re: Boeing 797 Discussion Thread - 2018

Fri Oct 19, 2018 2:27 am

Wonder if Boeing will us any of the design from the Aurora D8? I Boeing has a partnership with them and that plane kind of fits the bill. Google Aurora Flight Science D8 there is a video of a mock-up interior also.
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Re: Boeing 797 Discussion Thread - 2018

Fri Oct 19, 2018 3:18 am

HermansCVR580 wrote:
Wonder if Boeing will us any of the design from the Aurora D8? I Boeing has a partnership with them and that plane kind of fits the bill. Google Aurora Flight Science D8 there is a video of a mock-up interior also.


Interesting - thanks for sharing that. The inside certainly fits the narrative.
-Dave


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RJMAZ
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Re: Boeing 797 Discussion Thread - 2018

Fri Oct 19, 2018 3:46 am

https://youtu.be/H7Z04Tl1-1Q

The double bubble starts from the 4 minute mark.

Interesting concept.

Again it shows why it should be 8ab and stubby.
 
Strato2
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Re: Boeing 797 Discussion Thread - 2018

Fri Oct 19, 2018 3:52 am

Revelation wrote:
skystar767 wrote:
I don’t think this plane should be a wide body. A narrow body would be much better for Boeing. It would replace the 757 which most airlines around the world liked. The 737 max too low the 787 too big. I thing the 797 narrow body would give the A321lr a run for its money.

Sounds like you've never been in the last row of an A321 or 757-300 waiting for 200+ pax in front of you to deplane...


I'd certainly rather have a couple of minutes extra de-boarding time than a Boeing economy class seating standard for several hours.
 
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Revelation
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Re: Boeing 797 Discussion Thread - 2018

Fri Oct 19, 2018 11:51 am

Strato2 wrote:
Revelation wrote:
skystar767 wrote:
I don’t think this plane should be a wide body. A narrow body would be much better for Boeing. It would replace the 757 which most airlines around the world liked. The 737 max too low the 787 too big. I thing the 797 narrow body would give the A321lr a run for its money.

Sounds like you've never been in the last row of an A321 or 757-300 waiting for 200+ pax in front of you to deplane...

I'd certainly rather have a couple of minutes extra de-boarding time than a Boeing economy class seating standard for several hours.

You can get what you want, if you buy your own airplanes. Unfortunately the people who do buy airplanes work for airlines who are more interested in maximizing the airline's profits, and taking excessive time to board and deplane impacts their profits.
Last edited by Revelation on Fri Oct 19, 2018 11:57 am, edited 1 time in total.
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Re: Boeing 797 Discussion Thread - 2018

Fri Oct 19, 2018 11:53 am

Put in "18 inch" seats, 16 inch aisle(s), three seaters, incoming sidewalls, 28-29 inch pitch ultra slim seats and big IFE seat boxes and you will have the most miserable 18 inch seat experience of your life. You'll hang over into the aisle(s) and there the trolley and fellow passengers are unsuccessfully trying to not hit you all flight. And the airline will say the have industry standard width seats, 18 inch. Taking the public & media for a ride.

Image

Nobody is advertising their seatwidth boosting, half width armrest.
"Never mistake motion for action." Ernest Hemingway
 
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Re: Boeing 797 Discussion Thread - 2018

Fri Oct 19, 2018 12:55 pm

keesje wrote:
Put in "18 inch" seats, 16 inch aisle(s), three seaters, incoming sidewalls, 28-29 inch pitch ultra slim seats and big IFE seat boxes and you will have the most miserable 18 inch seat experience of your life. You'll hang over into the aisle(s) and there the trolley and fellow passengers are unsuccessfully trying to not hit you all flight. And the airline will say the have industry standard width seats, 18 inch. Taking the public & media for a ride.

Image

Nobody is advertising their seatwidth boosting, half width armrest.


I changed your picture because I don’t see how that relates to the 797. No one has shared any actual information on what the actual cabin width will be, so why are you talking about 16 inch wide seats?

Here is a quote from Air Transat on how they advertise the economy on their 9 abreast A330s

Our Economy Class offers a warm welcome and personalized service, with unparalleled comfort, ergonomic Italian-leather seats, a dedicated crew and an inflight entertainment system!


Marketing departments will try to make anything sound good.
 
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Re: Boeing 797 Discussion Thread - 2018

Fri Oct 19, 2018 1:07 pm

keesje wrote:
Put in "18 inch" seats, 16 inch aisle(s), three seaters, incoming sidewalls, 28-29 inch pitch ultra slim seats and big IFE seat boxes and you will have the most miserable 18 inch seat experience of your life. You'll hang over into the aisle(s) and there the trolley and fellow passengers are unsuccessfully trying to not hit you all flight. And the airline will say the have industry standard width seats, 18 inch. Taking the public & media for a ride.

I think you're taking the reality of an Air Asia X A330/A330neo and trying to project it on to NMA, before we even know NMA's actual dimensions.

This has all the markings of a classic FUD ( https://en.wikipedia.org/wiki/Fear,_unc ... _and_doubt ) campaign.

Yet again.
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keesje
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Re: Boeing 797 Discussion Thread - 2018

Fri Oct 19, 2018 1:28 pm

Responding to posts #3234 & 35 of RJMAZ & Lightsaber. The photo I posted is an ultra narrow 2-4-2 767, but we could as well use a 9 abreast A330 or 10 abreast 777 or A350. Claiming "18 inch" seat width while shaving of inches from arm rests and aisles is widely used to mislead the public. Also claims 2-3-2 NMA would be more comfortable than 3-3 is misleading. As said we don't know yet & a wide 3-3 can be far more comfortable than a cramped twin aisle. The airlines and OE are the last to debunk those misconceptions if it suits them..

Marketing departments will try to make anything sound good.


:checkmark:

I think you're taking the reality of an Air Asia X A330/A330neo and trying to project it on to NMA, before we even know NMA's actual dimensions.


Asia XA330neo? To be honest I have no idea what you are referencing Revelation.
"Never mistake motion for action." Ernest Hemingway
 
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Re: Boeing 797 Discussion Thread - 2018

Fri Oct 19, 2018 2:02 pm

When you consider just how many airlines have,are and will buy the 787 family,I would be more than surprised if the seats they recommend for the 797 are not identical to those in the 787.It makes marketing common sense in so many ways.You can call them whatever width you like (somewhere about 17in + or- depending on armrests).But whatever you call it,it is the de facto standard for thousands of aircaft now and in the future.Since it's going to fly much shorter legs there is no reason to be more expansive - but it won't be less- guaranteed!
I have not read one article from one journalist (those with access to the facts) that suggest it's going to be an 8ab in economy aircraft.All have stated it to be 7ab in Y.As a width it's actually very good for Premium (2x2x2) and Biz (at 2x1x2).
Have to wait for Paris for Boeing confirmation though.Then it will be Airbus' move!
A 'Plus Plus' 320 response would be to deliver an inferior product (to the 797)and the 338 NEO should have shown them that this will condemn them to a minority share of the sector ( and it has been stated as shelved).But if not that then what? Perhaps something radically different? Might just be the only way.
 
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Re: Boeing 797 Discussion Thread - 2018

Fri Oct 19, 2018 2:07 pm

keesje wrote:

I think you're taking the reality of an Air Asia X A330/A330neo and trying to project it on to NMA, before we even know NMA's actual dimensions.


Asia XA330neo? To be honest I have no idea what you are referencing Revelation.


I think that is exactly what you are doing. I am seeing all these strawman arguments about how cramped the NMA could be even though we have no idea what the actual dimensions will be. 2x3x2 configurations are vastly more comfortable woth fewer middle seats yet you keep posting about how 3x3 COULD be better if the 2x3x2 has narrow seats and aisles even though we have no evidence of that being the case
 
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Re: Boeing 797 Discussion Thread - 2018

Fri Oct 19, 2018 2:17 pm

Who cares about comfort for economy class? It can be miserable.
 
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keesje
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Re: Boeing 797 Discussion Thread - 2018

Fri Oct 19, 2018 2:54 pm

seahawk wrote:
Who cares about comfort for economy class? It can be miserable.


Boeing. Behind the curtains airlines forwarded the unfiltered passenger feedback on 777 10 abreast. So they decided to do huge investments in structure mods, widening the cabin, enlarging windows to make the 10 abreast acceptable, gaining empty weight in the process. Guess who in the end pay all the salaries, bonuses, infrastructure, development projects and jobs at Boeing..
"Never mistake motion for action." Ernest Hemingway
 
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Re: Boeing 797 Discussion Thread - 2018

Fri Oct 19, 2018 3:06 pm

skystar767 wrote:
I don’t think this plane should be a wide body. A narrow body would be much better for Boeing. It would replace the 757 which most airlines around the world liked. The 737 max too low the 787 too big. I thing the 797 narrow body would give the A321lr a run for its money.



Luckily, you aren't designing it. You have no idea what would be better for Boeing. You're just talking out of your hiney.
Whatever

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