Newbiepilot
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Re: Boeing 797 Thread - 2019

Tue Feb 12, 2019 3:20 pm

ewt340 wrote:
morrisond wrote:
Then in equivalent Densities you have MAX-10 at about 160-170 seats, NMA-6 about 200, NMA-7 about 230-240 and 788 about 288 - putting the NMA right in the middle of the market of Boeing's offerings.


Yes, but the main problem as I mentioned before is the lack of range for the larger model. Since B787-8 orders are drying up these days, it's only logical to amp up the range of the larger model to make it close to B767-300ER capability. Otherwise it's not gonna sell as well like B757-300 or B767-400ER. The smaller version capacity and range is great, they just gotta make some modifications for the larger model.


From what I keep reading (and quoted earlier in this thread) the larger 797 is optimized for domestic US, domestic China, Domestic India, Middle East to India and other markets under 2500nm. Chinese airports are running out of slots and Us airlines have consolidated to the point of having excessive frequency. This is the premise of widebody with narrowbody economics is that the plane is viable to displace 757s, A321ceos and 737-800s where airlines want to upgauge, but A330s and 787s are too expensive to be worthwhile for shorthaul. The widebodies don’t have particularly great CASM for short missions since they are way overbuilt for those types of routes and they cost too much to purchase.

Darren Hulst, a senior managing director of sales at Boeing's commercial aeroplane division, said the NMA was particularly compelling for Australian airlines who are struggling with capacity constraints between Sydney, Melbourne and Brisbane.

If it becomes a reality, the new wide-body (twin aisle) plane would fly between 220 to 270 passengers up to 5000 nautical miles, and could enter service as soon as 2025.

... “Whether you’re running out of slots or whether you’re just looking to optimise capacity for the peak levels of demand... an airplane that has the flexibility to carry 20 to 30 per cent more people at the right time is going to be compelling," Mr Hulst said on the sidelines of the International Air Transport Association's AMG in Sydney last week.


https://www.smh.com.au/business/compani ... 4zkto.html
 
jeffrey0032j
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Re: Boeing 797 Thread - 2019

Tue Feb 12, 2019 3:31 pm

ewt340 wrote:
morrisond wrote:
Then in equivalent Densities you have MAX-10 at about 160-170 seats, NMA-6 about 200, NMA-7 about 230-240 and 788 about 288 - putting the NMA right in the middle of the market of Boeing's offerings.


Yes, but the main problem as I mentioned before is the lack of range for the larger model. Since B787-8 orders are drying up these days, it's only logical to amp up the range of the larger model to make it close to B767-300ER capability. Otherwise it's not gonna sell as well like B757-300 or B767-400ER. The smaller version capacity and range is great, they just gotta make some modifications for the larger model.

Boeing is already starting to incorporate some of the 789 parts to streamline production, it is expected as a by-product of this move, some of the improvements done to the 789 will begin to appear on the 788, so we should expect a more efficient 788 coming along progressively.
 
flipdewaf
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Re: Boeing 797 Thread - 2019

Tue Feb 12, 2019 3:32 pm

Newbiepilot wrote:
ewt340 wrote:
morrisond wrote:
Then in equivalent Densities you have MAX-10 at about 160-170 seats, NMA-6 about 200, NMA-7 about 230-240 and 788 about 288 - putting the NMA right in the middle of the market of Boeing's offerings.


Yes, but the main problem as I mentioned before is the lack of range for the larger model. Since B787-8 orders are drying up these days, it's only logical to amp up the range of the larger model to make it close to B767-300ER capability. Otherwise it's not gonna sell as well like B757-300 or B767-400ER. The smaller version capacity and range is great, they just gotta make some modifications for the larger model.


From what I keep reading (and quoted earlier in this thread) the larger 797 is optimized for domestic US, domestic China, Domestic India, Middle East to India and other markets under 2500nm. Chinese airports are running out of slots and Us airlines have consolidated to the point of having excessive frequency. This is the premise of widebody with narrowbody economics is that the plane is viable to displace 757s, A321ceos and 737-800s where airlines want to upgauge, but A330s and 787s are too expensive to be worthwhile for shorthaul. The widebodies don’t have particularly great CASM for short missions since they are way overbuilt for those types of routes and they cost too much to purchase.


Are we to read optimised for under 2500nm as maximum of 4000nm?

Lots of things don't add up here, the thrust, the pax capacity, the range, the fuselage weight voodoo. I can see the numbers stacking together to form a direct 763 replacement but not a 763 replacement that beats a contemporary narrow body on costs.

Could be a lot of purposeful misdirection at play.

Fred
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jagraham
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Re: Boeing 797 Thread - 2019

Tue Feb 12, 2019 3:43 pm

The problem is that Boeing can replace the 763 directly but then they end up with a 783. And we know how that worked out.

Or Boeing goes for max fuel economy - small engines and long skinny wings. And fairly low MTOW.

The wings can allow a small widebody using uprated narrowbody engines. 5000nm seems doable for pax plus up to 5t cargo. The wings may have to fold . .
 
flipdewaf
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Re: Boeing 797 Thread - 2019

Tue Feb 12, 2019 3:52 pm

jagraham wrote:
The problem is that Boeing can replace the 763 directly but then they end up with a 783. And we know how that worked out.

Or Boeing goes for max fuel economy - small engines and long skinny wings. And fairly low MTOW.

The wings can allow a small widebody using uprated narrowbody engines. 5000nm seems doable for pax plus up to 5t cargo. The wings may have to fold . .


But this is the problem that does not compute, long skinny wings do not equal low MTOW.
Short stubby wings = high induced drag coefficient but low weight
Long skinny wings = Low induced drag coefficient but heavy

Fred
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jagraham
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Re: Boeing 797 Thread - 2019

Tue Feb 12, 2019 4:05 pm

flipdewaf wrote:
jagraham wrote:
The problem is that Boeing can replace the 763 directly but then they end up with a 783. And we know how that worked out.

Or Boeing goes for max fuel economy - small engines and long skinny wings. And fairly low MTOW.

The wings can allow a small widebody using uprated narrowbody engines. 5000nm seems doable for pax plus up to 5t cargo. The wings may have to fold . .


But this is the problem that does not compute, long skinny wings do not equal low MTOW.
Short stubby wings = high induced drag coefficient but low weight
Long skinny wings = Low induced drag coefficient but heavy

Fred


Composites help immensely with regards to weight in long skinny wings.

We could also see trusses make a comeback. Boeing just patented a truss design . .

Also if Boeing does it right most of the fuel will be in the center tank. Even a 767ER has 8000 gal in the center tank; the 787 and A330 are about 12000 gallons.
 
morrisond
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Re: Boeing 797 Thread - 2019

Tue Feb 12, 2019 4:14 pm

ewt340 wrote:
morrisond wrote:
Then in equivalent Densities you have MAX-10 at about 160-170 seats, NMA-6 about 200, NMA-7 about 230-240 and 788 about 288 - putting the NMA right in the middle of the market of Boeing's offerings.


Yes, but the main problem as I mentioned before is the lack of range for the larger model. Since B787-8 orders are drying up these days, it's only logical to amp up the range of the larger model to make it close to B767-300ER capability. Otherwise it's not gonna sell as well like B757-300 or B767-400ER. The smaller version capacity and range is great, they just gotta make some modifications for the larger model.


That may be why 50K engines are being floated maybe the larger NMA will have a higher MTOW than the smaller one to get similar range - just like 788/789.
 
Eyad89
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Re: Boeing 797 Thread - 2019

Tue Feb 12, 2019 4:45 pm

RJMAZ wrote:


No it's not. The 787-3 carried all most of the heavy bits from the 787-8. None of it was optimised for the short range mission.

A clean sheet design would have had:
A smaller landing gear.
Fully scaled down engines instead of a derate.
A smaller tail due to lower engine thrust.
Proper scaled down high aspect ratio wing.
Lighter centre wing box.
A lower max payload.



The 787-3 had most of the changes in that list, and that’s how it lost 19 tons in OEW.

To put things in perspective:
- The 788 is lighter than 789 by 9 tons even though the 789 has a heavier landing gear.
- The 788 is lighter than 78X by 16 tons.
- Now, the 787-3 was supposed to be lighter than 788 by 19 tons.

The 787-3 wasn’t a simple paper MTOW derate like the A330 Regional. It was structurally different than 788.

Yet, it had zero orders before it was canceled. Losing a few more tons in OEW wouldn’t make it drastically more appealing.
 
frmrCapCadet
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Re: Boeing 797 Thread - 2019

Tue Feb 12, 2019 5:29 pm

Boeing has announced a larger shorter range version and a smaller long range version. I don't think anyone on line here has run the numbers for each version's actual use.

i.e. How far could each version go if they lightened the load, how many can the squeeze in and then how far can the go. How short a run can they do and still be efficient, and et cetera? I understand that there are some standard formulas that can provide some answers.

Wikipedia does have a great page on the possible 797. It is strictly a history, year by year of what has been announced and speculated by Boeing, engine makers, and respected aviation figures.
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WIederling
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Re: Boeing 797 Thread - 2019

Tue Feb 12, 2019 5:41 pm

Eyad89 wrote:
The 787-3 had most of the changes in that list, and that’s how it lost 19 tons in OEW.
To put things in perspective:
- The 788 is lighter than 789 by 9 tons even though the 789 has a heavier landing gear. ???
- The 788 is lighter than 78X by 16 tons.
- Now, the 787-3 was supposed to be lighter than 788 by 19 tons.

The 787-3 wasn’t a simple paper MTOW derate like the A330 Regional. It was structurally different than 788.

Yet, it had zero orders before it was canceled. Losing a few more tons in OEW wouldn’t make it drastically more appealing.

789 vs 7810 OEW divided by length delta gives you the fuselage weight per m : 1.2t/m
1.2t/ time delta 788 789 -> 7.3t, real difference 8.9t -> ~~1.6t is extra structure on the 789.

Issue with the 783 was that any flight longer than 2..300nm would have been more efficient with the heavier 788.

IMU your 783 OEW numbers are either misunderstood or from way back when the 788 would swim on milk too.
Murphy is an optimist
 
flipdewaf
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Re: Boeing 797 Thread - 2019

Tue Feb 12, 2019 5:55 pm

WIederling wrote:
Eyad89 wrote:
The 787-3 had most of the changes in that list, and that’s how it lost 19 tons in OEW.
To put things in perspective:
- The 788 is lighter than 789 by 9 tons even though the 789 has a heavier landing gear. ???
- The 788 is lighter than 78X by 16 tons.
- Now, the 787-3 was supposed to be lighter than 788 by 19 tons.

The 787-3 wasn’t a simple paper MTOW derate like the A330 Regional. It was structurally different than 788.

Yet, it had zero orders before it was canceled. Losing a few more tons in OEW wouldn’t make it drastically more appealing.

789 vs 7810 OEW divided by length delta gives you the fuselage weight per m : 1.2t/m
1.2t/ time delta 788 789 -> 7.3t, real difference 8.9t -> ~~1.6t is extra structure on the 789.

Issue with the 783 was that any flight longer than 2..300nm would have been more efficient with the heavier 788.

IMU your 783 OEW numbers are either misunderstood or from way back when the 788 would swim on milk too.

Be careful, you cannot attribute all the extra weight to the fuselage, the wing will have an increased weight in the -10 due to the higher MZFW.

Fred


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WIederling
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Re: Boeing 797 Thread - 2019

Tue Feb 12, 2019 6:05 pm

flipdewaf wrote:
Be careful, you cannot attribute all the extra weight to the fuselage, the wing will have an increased weight in the -10 due to

Higher MZFW goes against less fuel in the center tank as MTOW stays the same. a wash afaics?
Murphy is an optimist
 
flipdewaf
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Re: Boeing 797 Thread - 2019

Tue Feb 12, 2019 7:04 pm

WIederling wrote:
flipdewaf wrote:
Be careful, you cannot attribute all the extra weight to the fuselage, the wing will have an increased weight in the -10 due to

Higher MZFW goes against less fuel in the center tank as MTOW stays the same. a wash afaics?

The MZFW is the ultimate load case for wing strength. It is because there is no bending relief from the fuel load in the wings. When an aircraft has a centre tank it is highly unlikely that:
a. It will require being utilised when the aircraft is at max payload.
b. Add more to the bending moment than that being relieved by the fuel in the wings.

It’s pretty safe to assume that for any transport category aircraft will have maximum wing bending Moment at MZFW.

Fred


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Eyad89
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Re: Boeing 797 Thread - 2019

Tue Feb 12, 2019 7:10 pm

WIederling wrote:


IMU your 783 OEW numbers are either misunderstood or from way back when the 788 would swim on milk too.



I got the OEW as well as other specs from several articles that were published back then when 787-3 was still a thing.

Sure, you can dismiss those figures as unreliable, 787-3 is like the A358 afterall: stillborns.
 
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seabosdca
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Re: Boeing 797 Thread - 2019

Tue Feb 12, 2019 7:25 pm

Eyad89 wrote:
The 787-3 had most of the changes in that list, and that’s how it lost 19 tons in OEW.

To put things in perspective:
- The 788 is lighter than 789 by 9 tons even though the 789 has a heavier landing gear.
- The 788 is lighter than 78X by 16 tons.
- Now, the 787-3 was supposed to be lighter than 788 by 19 tons.

The 787-3 wasn’t a simple paper MTOW derate like the A330 Regional. It was structurally different than 788.


My memory of the time is that the original OEW goal was widely recognized as a pipe dream and that Boeing was struggling to make the 783 even 10 tonnes lighter than a 788. If that's accurate, it certainly explains why the 783 stopped looking attractive even for Japanese domestic service.

In hindsight it seems pretty clear that the 788 fuselage was somewhat overengineered, but it was Boeing's first all-composite fuselage and they didn't yet have the knowledge to be super-aggressive about taking weight out.

I can appreciate that a 787-size aircraft 20 tonnes lighter than a 788 would change a lot of things, but I also don't think that's the size of aircraft Boeing's customers are looking for with the 797.
 
iamlucky13
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Re: Boeing 797 Thread - 2019

Tue Feb 12, 2019 7:54 pm

Eyad89 wrote:
RJMAZ wrote:


No it's not. The 787-3 carried all most of the heavy bits from the 787-8. None of it was optimised for the short range mission.

A clean sheet design would have had:
A smaller landing gear.
Fully scaled down engines instead of a derate.
A smaller tail due to lower engine thrust.
Proper scaled down high aspect ratio wing.
Lighter centre wing box.
A lower max payload.



The 787-3 had most of the changes in that list, and that’s how it lost 19 tons in OEW.

To put things in perspective:
- The 788 is lighter than 789 by 9 tons even though the 789 has a heavier landing gear.
- The 788 is lighter than 78X by 16 tons.
- Now, the 787-3 was supposed to be lighter than 788 by 19 tons.

The 787-3 wasn’t a simple paper MTOW derate like the A330 Regional. It was structurally different than 788.

Yet, it had zero orders before it was canceled. Losing a few more tons in OEW wouldn’t make it drastically more appealing.


Aside from the points others have made, the 797 won't be, or rather it must not be, merely a "few tons" lighter than the 787-3. It just plain would stand no chance if its OEW is nearly as much as the A321XLR MTOW and more than the 767 OEW.

It needs to be something more like 30 tonnes lighter than the 787-3 would have been. That would place it in between the 757 and 767 for OEW.

And it's not just about weight. Truncating a wing designed for a 225 tonne MTOW, 8000 mile aircraft to fit a much shorter range mission was far from optimal aerodynamically.

And of course, there is the much-debated rumor it will have a flattened fuselage cross section for additional drag reduction.

The 787-3 simply does not work as a point of comparison to assess the business case for the MoM.
 
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keesje
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Re: Boeing 797 Thread - 2019

Tue Feb 12, 2019 8:17 pm

The 787-3 was basically a 787-8 with shortened wings. To keep commonality high and costs down the same engines, wing box and main wing and system were 787 standard. The landing gear was probably the same, not for MLW landings but for high cycles. I wonder if they shaved of more than 5t of the 788 OEW, 115t? Not even close to the 767 and A300 who are way below 100t. Luckely Boeing, ANA, JAL saw the writing on the wall and took the right decision before wasting a lot of money.
"Never mistake motion for action." Ernest Hemingway
 
RJMAZ
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Re: Boeing 797 Thread - 2019

Tue Feb 12, 2019 8:39 pm

Eyad89 wrote:
RJMAZ wrote:


No it's not. The 787-3 carried all most of the heavy bits from the 787-8. None of it was optimised for the short range mission.

A clean sheet design would have had:
A smaller landing gear.
Fully scaled down engines instead of a derate.
A smaller tail due to lower engine thrust.
Proper scaled down high aspect ratio wing.
Lighter centre wing box.
A lower max payload.


The 787-3 had most of the changes in that list, and that’s how it lost 19 tons in OEW.

Most? 3 out of the 6 points is not most. You'll need to look much further than wikipedia to see the correct history of the 787-3.

The 787-3 had inefficient derated engines, they were not scaled down.

The 787-3 shared the 787-8 tail, it was not scaled down.

The 787-3 wing was not scaled down, it had the wing tips removed and a poor aspect ratio.

Despite the 787-3 only having 3 out of 6 points it managed to secure 20% of the launch orders. ANA for examplr ordered 30 787-3's and 20 787-8's on launch day. JAL ordered 787-3s too. The 787-3 was planned to be the second 787 aircraft to be produced.

Development problems and delays then appeared early in the 787 program. To keep the program on schedule Boeing decided to make the 787-9 second and the 787-3 third. This added years to the service date of the 787-3. This made it hard to get new 787-3 sales.

More delays then piled up after this decision. Boeing was forced to reduce the optimisation of the 787-3 even further. It was to now share the same wingbox and fuselage structure and gained a 5T and fuel burn became worse. The 787-3 had now become a paper derate of the 787-8 with the wing tips chopped off. It now had only 1 of the 6 points I mentioned.

The 787-3 now had most of the weight of the 787-8 with less lift. All orders were then swapped to 787-8's as the 787-3's performance was reduced so much that it actually burnt more fuel on flights over 200nm.

The 787-3 history is irrelevant to the 797.
 
flipdewaf
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Re: Boeing 797 Thread - 2019

Tue Feb 12, 2019 8:46 pm

jagraham wrote:
flipdewaf wrote:
jagraham wrote:
The problem is that Boeing can replace the 763 directly but then they end up with a 783. And we know how that worked out.

Or Boeing goes for max fuel economy - small engines and long skinny wings. And fairly low MTOW.

The wings can allow a small widebody using uprated narrowbody engines. 5000nm seems doable for pax plus up to 5t cargo. The wings may have to fold . .


But this is the problem that does not compute, long skinny wings do not equal low MTOW.
Short stubby wings = high induced drag coefficient but low weight
Long skinny wings = Low induced drag coefficient but heavy

Fred


Composites help immensely with regards to weight in long skinny wings. .
they help on short wings too, and on narrow body wings.

jagraham wrote:
We could also see trusses make a comeback. Boeing just patented a truss design . . .
lol, I’ll eat my hat if there is a truss braced wing on the 797.

jagraham wrote:
Also if Boeing does it right most of the fuel will be in the center tank. Even a 767ER has 8000 gal in the center tank; the 787 and A330 are about 12000 gallons.
if Boeing does it right ( I’m sure they will, they are clever people) they will put as much fuel as possible as far out on the wing as they reasonably can and use the centre tank only if they get above max volume For the ranges they want to achieve.

Fred



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bigjku
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Re: Boeing 797 Thread - 2019

Tue Feb 12, 2019 9:05 pm

flipdewaf wrote:
jagraham wrote:
flipdewaf wrote:

But this is the problem that does not compute, long skinny wings do not equal low MTOW.
Short stubby wings = high induced drag coefficient but low weight
Long skinny wings = Low induced drag coefficient but heavy

Fred


Composites help immensely with regards to weight in long skinny wings. .
they help on short wings too, and on narrow body wings.

jagraham wrote:
We could also see trusses make a comeback. Boeing just patented a truss design . . .
lol, I’ll eat my hat if there is a truss braced wing on the 797.

jagraham wrote:
Also if Boeing does it right most of the fuel will be in the center tank. Even a 767ER has 8000 gal in the center tank; the 787 and A330 are about 12000 gallons.
if Boeing does it right ( I’m sure they will, they are clever people) they will put as much fuel as possible as far out on the wing as they reasonably can and use the centre tank only if they get above max volume For the ranges they want to achieve.

Fred



Sent from my iPhone using Tapatalk


A truss wing makes little sense on the ranges talked about as it limits speed. Now if you use such a wing on an aircraft with much shorter range it makes sense. But I agree, on the first portion of the NMA program you won’t see it.
 
jagraham
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Re: Boeing 797 Thread - 2019

Wed Feb 13, 2019 3:56 am

bigjku wrote:
flipdewaf wrote:
jagraham wrote:

Composites help immensely with regards to weight in long skinny wings. .
they help on short wings too, and on narrow body wings.

jagraham wrote:
We could also see trusses make a comeback. Boeing just patented a truss design . . .
lol, I’ll eat my hat if there is a truss braced wing on the 797.

jagraham wrote:
Also if Boeing does it right most of the fuel will be in the center tank. Even a 767ER has 8000 gal in the center tank; the 787 and A330 are about 12000 gallons.
if Boeing does it right ( I’m sure they will, they are clever people) they will put as much fuel as possible as far out on the wing as they reasonably can and use the centre tank only if they get above max volume For the ranges they want to achieve.

Fred



Sent from my iPhone using Tapatalk


A truss wing makes little sense on the ranges talked about as it limits speed. Now if you use such a wing on an aircraft with much shorter range it makes sense. But I agree, on the first portion of the NMA program you won’t see it.


Boeing's new truss is itself a wing. Not saying they will use it on 797 (I don't think it's necessary), but if the spars got too heavy a truss would solve the problem.
 
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keesje
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Re: Boeing 797 Thread - 2019

Wed Feb 13, 2019 7:50 am

Man, we are dying for some real, substantial news. :drool:

Dhierin Bechai rehashes some considerations, carefully looking if maybe the 797 should be a bit smaller. Remarkable because he invariably concludes Boeing is on the right track buy buy.

In the end he feels Boeing better stays away from a pure 757 replacement, because the installed base of the A321 and time to market of new A321NEO variants seems very competitive.

https://seekingalpha.com/article/4238381-boeing-797-pure-boeing-757-replacement

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"Never mistake motion for action." Ernest Hemingway
 
ewt340
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Re: Boeing 797 Thread - 2019

Wed Feb 13, 2019 1:22 pm

keesje wrote:
Man, we are dying for some real, substantial news. :drool:

Dhierin Bechai rehashes some considerations, carefully looking if maybe the 797 should be a bit smaller. Remarkable because he invariably concludes Boeing is on the right track buy buy.

In the end he feels Boeing better stays away from a pure 757 replacement, because the installed base of the A321 and time to market of new A321NEO variants seems very competitive.

https://seekingalpha.com/article/4238381-boeing-797-pure-boeing-757-replacement

Image


The cheaper option would be to make replacement for both B737-800 and B757-200 at the same time. Making only B757-200 replacement with 1 type of engines would be useless. Making B737-800 and B757-200 replacement make sense from financial perspective to compete with A32Xneo.
A new clean sheet of 6-abreas configurations, so we don't need to worry about then ULD paradox as well.

Max capacity at 200 seats and 250 seats in 28" pitch for LCC. Or the 170-200 seat for the premium configurations.

Thrust at 50k-60k for the smaller model similar to B737MAX8. And then 80k-90k for the larger model.

Range should be around 3,600 - 4,000 nmi for the smaller model and then 5,000 nmi for the larger model.

Let Embraer handle he 70-150 seat market instead. It's not like B737MAX7 sell well recently.

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Last edited by ewt340 on Wed Feb 13, 2019 1:49 pm, edited 1 time in total.
 
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trpmb6
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Re: Boeing 797 Thread - 2019

Wed Feb 13, 2019 1:48 pm

jagraham wrote:
bigjku wrote:
flipdewaf wrote:
they help on short wings too, and on narrow body wings.

lol, I’ll eat my hat if there is a truss braced wing on the 797.

if Boeing does it right ( I’m sure they will, they are clever people) they will put as much fuel as possible as far out on the wing as they reasonably can and use the centre tank only if they get above max volume For the ranges they want to achieve.

Fred



Sent from my iPhone using Tapatalk


A truss wing makes little sense on the ranges talked about as it limits speed. Now if you use such a wing on an aircraft with much shorter range it makes sense. But I agree, on the first portion of the NMA program you won’t see it.


Boeing's new truss is itself a wing. Not saying they will use it on 797 (I don't think it's necessary), but if the spars got too heavy a truss would solve the problem.


The truss is not a wing (maybe you can call it a lifting body but the drag resulting from a truss far exceeds any beneficial lift you'd get) It's nothing more than a slightly more efficient way to handle the loads of a very high aspect ratio wing where the reduction in induced drag (due to the higher aspect ratio wing) can offset the drag caused by the truss itself.

Boeing is not considering trussing the 797. It's not even in the deck of cards.
 
Eyad89
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Re: Boeing 797 Thread - 2019

Wed Feb 13, 2019 5:48 pm

RJMAZ wrote:

Most? 3 out of the 6 points is not most. You'll need to look much further than wikipedia to see the correct history of the 787-3.

The 787-3 had inefficient derated engines, they were not scaled down.

The 787-3 shared the 787-8 tail, it was not scaled down.

The 787-3 wing was not scaled down, it had the wing tips removed and a poor aspect ratio.

Despite the 787-3 only having 3 out of 6 points it managed to secure 20% of the launch orders. ANA for examplr ordered 30 787-3's and 20 787-8's on launch day. JAL ordered 787-3s too. The 787-3 was planned to be the second 787 aircraft to be produced.

Development problems and delays then appeared early in the 787 program. To keep the program on schedule Boeing decided to make the 787-9 second and the 787-3 third. This added years to the service date of the 787-3. This made it hard to get new 787-3 sales.

More delays then piled up after this decision. Boeing was forced to reduce the optimisation of the 787-3 even further. It was to now share the same wingbox and fuselage structure and gained a 5T and fuel burn became worse. The 787-3 had now become a paper derate of the 787-8 with the wing tips chopped off. It now had only 1 of the 6 points I mentioned.

The 787-3 now had most of the weight of the 787-8 with less lift. All orders were then swapped to 787-8's as the 787-3's performance was reduced so much that it actually burnt more fuel on flights over 200nm.



To be honest, I didn't know that Boeing reduced the optimization of 787-3 after the program delays. This does change things somewhat. However, their initial 787-3 proposal was aimed to be a 762/763 replacement.

I also think the 787-3 wasn't supposed to have 788 wings minus raked wingtips. Since its wing span was 9m shorter, then the wings themselves must have been shorter. I don't think the 787 raked wingtips are 9m long (4.5m on each side)

RJMAZ wrote:
The 787-3 history is irrelevant to the 797.


Absolutely. We are talking about Boeing here, they wouldn't launch a 787-3 replica after what it went through. Boeing never launched a program that failed to sell (but they launched variants that didn't sell, different story) It was just me arguing against a 797 that would have a 788 fuselage even though it would be more optimized than the 787-3.
 
iamlucky13
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Re: Boeing 797 Thread - 2019

Wed Feb 13, 2019 9:13 pm

ewt340 wrote:
Let Embraer handle he 70-150 seat market instead. It's not like B737MAX7 sell well recently.


The 737 has been selling quite well recently.

For the last decade, orders have exceeded deliveries every single year except 2009 (recession), with a total of 7384 orders to 4588 deliveries. Last year it was 180 more orders than deliveries. The year before it was nearly 300.

Put another way, over a period where the production rate gradually increased from 31.5 per month to 52 per month with an average of 38.2, the average order intake has been 61.5 aircraft per month.

Of course, the A320 is selling even better. Yet regardless of whether the 737's are selling on their own merits, based on low pricing, or simply because Airbus can't build A320NEO's quickly enough, the 737 is still in strong demand. Since the recent order history exceeds the market forecasts, it appears we are due for a slowdown in orders, but barring a major, sustained, global airline downturn, a radical shift in the order balance between the 737 and the A320, or the C919 significantly exceeding expectations, it appears to me there is no urgency yet to replace the 737.

Eyad89 wrote:
Absolutely. We are talking about Boeing here, they wouldn't launch a 787-3 replica after what it went through. Boeing never launched a program that failed to sell (but they launched variants that didn't sell, different story) It was just me arguing against a 797 that would have a 788 fuselage even though it would be more optimized than the 787-3.


This significantly helps clarify your prior post. Thank you.
 
ewt340
Posts: 464
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Re: Boeing 797 Thread - 2019

Wed Feb 13, 2019 9:56 pm

iamlucky13 wrote:
ewt340 wrote:
Let Embraer handle he 70-150 seat market instead. It's not like B737MAX7 sell well recently.


The 737 has been selling quite well recently.

For the last decade, orders have exceeded deliveries every single year except 2009 (recession), with a total of 7384 orders to 4588 deliveries. Last year it was 180 more orders than deliveries. The year before it was nearly 300.

Put another way, over a period where the production rate gradually increased from 31.5 per month to 52 per month with an average of 38.2, the average order intake has been 61.5 aircraft per month.

Of course, the A320 is selling even better. Yet regardless of whether the 737's are selling on their own merits, based on low pricing, or simply because Airbus can't build A320NEO's quickly enough, the 737 is still in strong demand. Since the recent order history exceeds the market forecasts, it appears we are due for a slowdown in orders, but barring a major, sustained, global airline downturn, a radical shift in the order balance between the 737 and the A320, or the C919 significantly exceeding expectations, it appears to me there is no urgency yet to replace the 737.

Eyad89 wrote:
Absolutely. We are talking about Boeing here, they wouldn't launch a 787-3 replica after what it went through. Boeing never launched a program that failed to sell (but they launched variants that didn't sell, different story) It was just me arguing against a 797 that would have a 788 fuselage even though it would be more optimized than the 787-3.


This significantly helps clarify your prior post. Thank you.


Read the comment again, B737MAX7, not all B737. 61 orders so far. A319neo have 55 instead.

It also doesn't mean that they have to launch this new aircraft now. If they decided to do 6-abreast B797 to replace B737-800 and B757-200. They have to wait till at least 2030.
Especially since there is a rumor floating around on how Airbus want to launch new clean sheet design to replace A32Xneo in 2025.
 
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Re: Boeing 797 Thread - 2019

Thu Feb 21, 2019 1:00 pm

In https://aviationweek.com/program-manage ... -done-deal the man who was right about the A380 all along, Richard Aboulafia, writes about the challenges facing NMA and concludes:

Even with these challenges, it’s clear that Boeing needs to do something in the midsize segment. Given the growth prospects, abandoning this segment to Airbus for a decade or longer is unpalatable. The alternative to the NMA—launching a new, larger single-aisle family—would make the 737 MAX no more than a 10-year program, clearly an unappealing decision. And despite Boeing’s desire to return a very high percentage of its cash to shareholders, it certainly has the resources needed to launch the NMA. The company’s engineers also will need to work on something after the 777X development program winds down in the early 2020s.

So, regardless of the difficulties complicating the NMA decision, the new jet remains in the Teal Group’s forecast. But if there is no authorization to offer this year, Boeing would clearly say that the NMA’s challenges outweigh its opportunities.

No prediction of a 2019 NSA to be found here.
Wake up to find out that you are the eyes of the world
The heart has its beaches, its homeland and thoughts of its own
Wake now, discover that you are the song that the morning brings
The heart has its seasons, its evenings and songs of its own
 
JayinKitsap
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Re: Boeing 797 Thread - 2019

Thu Feb 21, 2019 4:21 pm

Boeing has two projects that are great to test out the digital plane software and a 'mid-term" test of the designers.

The MQ-25 was awarded 30 AUG 18, Boeing had a concept prototype that could taxi but not fly. Not big but very important to Boeing, it flies off carriers and gives an opening to more variations. Boeing probably is going at things heavy with this contract.

The T-X trainer was awarded 27 SEP 18 for over 400 potential Jet Trainers. Boeing joined with Saab in DEC 13 and on 20 DEC 16, first flight of the prototype in 3 years. Two were built. I suspect that these prototypes are not quite the production model but they seem to have a hot product for the USAF. Probably 100's and possibly 500 engineers are working hard and fast right now, what better training than to do a sports car for an exercise. Also, needs lots of contracts singed, sealed, and delivered with probably the contracts are approached for the MOM.

The industry was quite surprised where Boeing's pricing on these two plus the Marine heli award, but they walked away with 3 after a long dry spell. No protests on any of the 3. Boeing was pricing it like a production business jet, which will either cost them dearly but if they have their act together could be a realy money maker for them. My point for this thread is the apparent 797 quiet period coincides with these landing in their IN box. A good training opportunity before going for more 797, I believe these awards floated the ATO and Launch by 6 months.

Meanwhile, there is probably some heavy wrestling getting the engine contract into form, design of the production, etc . It is interesting is the reports from the airlines are in the new for years, but quite quiet on the supplier front, that we hear. Is more in house this time - yes, certainly the design. But the APU JV with Safron points to the 797 being quite real, what other APU will they be working on.

Another thing possibly stretching the timeline is the Embraer JV, it may need to be finalized before ATO for some reason.
 
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Re: Boeing 797 Thread - 2019

Thu Feb 21, 2019 7:26 pm

JayinKitsap wrote:
Boeing has two projects that are great to test out the digital plane software and a 'mid-term" test of the designers.

The MQ-25 was awarded 30 AUG 18, Boeing had a concept prototype that could taxi but not fly. Not big but very important to Boeing, it flies off carriers and gives an opening to more variations. Boeing probably is going at things heavy with this contract.

The T-X trainer was awarded 27 SEP 18 for over 400 potential Jet Trainers. Boeing joined with Saab in DEC 13 and on 20 DEC 16, first flight of the prototype in 3 years. Two were built. I suspect that these prototypes are not quite the production model but they seem to have a hot product for the USAF. Probably 100's and possibly 500 engineers are working hard and fast right now, what better training than to do a sports car for an exercise. Also, needs lots of contracts singed, sealed, and delivered with probably the contracts are approached for the MOM.

The industry was quite surprised where Boeing's pricing on these two plus the Marine heli award, but they walked away with 3 after a long dry spell. No protests on any of the 3. Boeing was pricing it like a production business jet, which will either cost them dearly but if they have their act together could be a realy money maker for them. My point for this thread is the apparent 797 quiet period coincides with these landing in their IN box. A good training opportunity before going for more 797, I believe these awards floated the ATO and Launch by 6 months.

Meanwhile, there is probably some heavy wrestling getting the engine contract into form, design of the production, etc . It is interesting is the reports from the airlines are in the new for years, but quite quiet on the supplier front, that we hear. Is more in house this time - yes, certainly the design. But the APU JV with Safron points to the 797 being quite real, what other APU will they be working on.

Another thing possibly stretching the timeline is the Embraer JV, it may need to be finalized before ATO for some reason.

I agree with what you wrote. Even the recently discussed FG article ( https://www.flightglobal.com/news/artic ... 37-455844/ ) said:

"We don't see the next new airplane, if we do middle of the market, as being a technology push airplane," it says. "There is significant technology reuse on things like composites manufacturing, and we would be more focused on manufacturing transformation for the NMA."

Basically the plan is to stick to known / proven technologies and put the focus on "manufacturing transformation" instead.

I think the aerospace industry is looking at examples such as SpaceX and deciding its focus on horizontal integration went too far and they can make a lot more money if they keep more work in house.
Wake up to find out that you are the eyes of the world
The heart has its beaches, its homeland and thoughts of its own
Wake now, discover that you are the song that the morning brings
The heart has its seasons, its evenings and songs of its own

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