Newbiepilot wrote:

Regardless of what the 797 is, I expect Airbus will find a way to respond. We have a thread for that topic already

viewtopic.php?t=1374459

That thread is purely based on speculation.

A more realistic look at how Airbus might respond can be found at Airbus weighs response if Boeing launches new mid-market model

neutrino wrote:

Actually, it looks like you are the one trying "to rewrite a bit of history" or maybe you are just plain forgetful, or something else.....
That slogan originated from Airbus. Virgin simply adopted it. Hope this is now clear to you. If not, Mr Google can help further. Cheers.

I was asking a question on the slogan. I was commenting on the re-writing of history on the 787 response. Now we will never know what exactly the thinking was in the boardroom or CEO's office, but what we do know is that Airbus was struggling with resources to get the A380 out of the building and ready for production. But seeing the Boeing response to the A321 taking most of the market is taking a lot of time it seems that Airbus has taken take that long really. From talks of a model needed as a response to two models being made available has taken about 13 years. If the 797 EIS in mid 2020 then you are looking at around 10 years or more as well. These things take time especially when you have commitments elsewhere that takes away from your available resources.

ikramerica wrote:

morrisond wrote:

Here is a good graphic of what the 797 cross section will more likely be - compared to those above and below. I think this is pretty much on the money.

https://s.yimg.com/fz/api/res/1.2/iaCbn ... 9x1024.png

No way. It will be round or taller than long. It's not going to be wider than tall. Further there is no need to be 5m wide at 7Y with 17.2" seats and sculpted side walls. A modern design could be almost 1 foot narrower than the 767.

I agree with you on the width - I don't think it needs to be more than 186" but I disagree on the height. I don't think it needs to be much more than 170". It doesn't need to be an elipse it could be the double bubble - Half of a 186" circle on top with a third of a wider circle on the bottom.

But who knows what they make - although it sounds like we might possibly see sooner rather than later.

Alan Joyce says its a widebody and economics look good

https://www.ausbt.com.au/qantas-eyes-bo ... stic-fleet

chiki wrote:

Alan Joyce says its a widebody and economics look good

https://www.ausbt.com.au/qantas-eyes-bo ... stic-fleet

Interesting. This is the most definitive statement I've heard from an actual customer that specifically cites the need and the (presumed) solution, in the form we've all speculated about. The fact that Joyce doesn't mention the A321LR at all is another thing... I wonder why?

The 797 will sell like hot cakes. QF is making a clear commitment in this interview. I can see Boeing launch with over 500 orders in the books.

c933103 wrote:

That would probably be too much capacity to what have been proposed, hence most likely it won't go to 8-abreast, and could instead be 7-abreast. As a widebody it could also start at a length shorter than A321

7 abreast can't match the economics of a 6 abreast.

Assuming 18inch seats and 18inch aisles.

6 abreast is 126inch wide cabin.

7 abreast is 162inch wide cabin. That is 28.5% wider for only 16.6% more seats. 28.5 is 72% greater than 16.5.

8 abreast is 180ich wide cabin that is 42.8% wider for 33.3% more seats. 42.8 is only 28% greater than 33.3

This should hopefully end any rumours of a 7 abreast.

The efficiency target of the mom has to be extremely high. If it can't match the narrow bodies on short routes it won't sell. If it can't match a 787 on medium haul routes it won't sell. The only way this is achievable is with 8 abreast.

My reduced height double bubble fuselage has an average diameter of 4.9metres. The A310, A300 and A330 has a diameter of 5.64metres. At 46metres long the 797-8 its not short and stubby either. Its similar to the 767 and 787 models.

RJMAZ wrote:

c933103 wrote:

That would probably be too much capacity to what have been proposed, hence most likely it won't go to 8-abreast, and could instead be 7-abreast. As a widebody it could also start at a length shorter than A321

7 abreast can't match the economics of a 6 abreast.

Assuming 18inch seats and 18inch aisles.

6 abreast is 126inch wide cabin.

7 abreast is 162inch wide cabin. That is 28.5% wider for only 16.6% more seats. 28.5 is 72% greater than 16.5.

8 abreast is 180ich wide cabin that is 42.8% wider for 33.3% more seats. 42.8 is only 28% greater than 33.3

This should hopefully end any rumours of a 7 abreast.

The efficiency target of the mom has to be extremely high. If it can't match the narrow bodies on short routes it won't sell. If it can't match a 787 on medium haul routes it won't sell. The only way this is achievable is with 8 abreast.

My reduced height double bubble fuselage has an average diameter of 4.9metres. The A310, A300 and A330 has a diameter of 5.64metres. At 46metres long the 797-8 its not short and stubby either. Its similar to the 767 and 787 models.

Well, I for one, have been most appreciative of your well-considered speculations and underlying calculations.
I will be most interested to see if you've "guessed right", because my non-aeronautic engineering mind cannot find any quibble with your thoughts (putting aside the pressurizations stresses challeges posed previous, of which I'm not qualified to understand).

What you say above about the diameter relative to to the A300 tube is rather striking . Is it accurate that the 767 has a 5.03m diameter?

FlyHappy wrote:

chiki wrote:

Alan Joyce says its a widebody and economics look good

https://www.ausbt.com.au/qantas-eyes-bo ... stic-fleet

Interesting. This is the most definitive statement I've heard from an actual customer that specifically cites the need and the (presumed) solution, in the form we've all speculated about. The fact that Joyce doesn't mention the A321LR at all is another thing... I wonder why?

Because Qantas is not looking for range but for a higher-capacity aircraft that is lighter than B787/A330.

VS11 wrote:

FlyHappy wrote:

chiki wrote:

Alan Joyce says its a widebody and economics look good

https://www.ausbt.com.au/qantas-eyes-bo ... stic-fleet

Interesting. This is the most definitive statement I've heard from an actual customer that specifically cites the need and the (presumed) solution, in the form we've all speculated about. The fact that Joyce doesn't mention the A321LR at all is another thing... I wonder why?

Because Qantas is not looking for range but for a higher-capacity aircraft that is lighter than B787/A330.

Indeed, I actually meant A321Neo in 240 pax form (though I realize not necessarily QF desired config).
I also realize the answer to that would be: QF desires more pax in 2 class arrangement, etc.

my question was a touch rhetorical. Seems to me Joyce doesn't see a viable proposed Airbus solution to his MoM need, and so, by extension, I wonder how many other markets see the same.

enzo011 wrote:

neutrino wrote:

Actually, it looks like you are the one trying "to rewrite a bit of history" or maybe you are just plain forgetful, or something else.....
That slogan originated from Airbus. Virgin simply adopted it. Hope this is now clear to you. If not, Mr Google can help further. Cheers.

I was asking a question on the slogan. I was commenting on the re-writing of history on the 787 response. Now we will never know what exactly the thinking was in the boardroom or CEO's office, but what we do know is that Airbus was struggling with resources to get the A380 out of the building and ready for production. But seeing the Boeing response to the A321 taking most of the market is taking a lot of time it seems that Airbus has taken take that long really. From talks of a model needed as a response to two models being made available has taken about 13 years. If the 797 EIS in mid 2020 then you are looking at around 10 years or more as well. These things take time especially when you have commitments elsewhere that takes away from your available resources.

Fair enough now that you made a clear separation between your first sentence question and the subsequent comment.

FlyHappy wrote:

What you say above about the diameter relative to to the A300 tube is rather striking . Is it accurate that the 767 has a 5.03m diameter?

767 - 5.03m exterior width. 4.72m cabin width. 5.41m exterior height. Its taller than it is wide.

a330 5.64m exterior width and height. 5.28m cabin width.

The 767 and A330 are pretty comfortable in 7 and 8 abreast respectively. So any new aircraft would be a foot narrower with slightly narrower seats and aisle.

My 797 design has a 5.3m exterior width and 4.4m height. 5m cabin width for a tight 8 abreast. That is 90% of the frontal area of a 767 but with an extra seat in the width. My shortest design at 46m is only 2m shorter than a 762 so its actually more slender. A perfect slender ratio. The 797-10 design is just as skinny as the A321.

If the oval design doesnt work a 5.3m perfectly circular MOM fuselage isn't too bad either. 94% the cross section of an A330 with a slightly narrower LD2 container instead of LD3. It would weigh the same as my oval design but have slightly more drag. Range figures might drop 5%.

RJMAZ wrote:

c933103 wrote:

That would probably be too much capacity to what have been proposed, hence most likely it won't go to 8-abreast, and could instead be 7-abreast. As a widebody it could also start at a length shorter than A321

7 abreast can't match the economics of a 6 abreast.

Assuming 18inch seats and 18inch aisles.

6 abreast is 126inch wide cabin.

7 abreast is 162inch wide cabin. That is 28.5% wider for only 16.6% more seats. 28.5 is 72% greater than 16.5.

8 abreast is 180ich wide cabin that is 42.8% wider for 33.3% more seats. 42.8 is only 28% greater than 33.3

This should hopefully end any rumours of a 7 abreast.

The efficiency target of the mom has to be extremely high. If it can't match the narrow bodies on short routes it won't sell. If it can't match a 787 on medium haul routes it won't sell. The only way this is achievable is with 8 abreast.

My reduced height double bubble fuselage has an average diameter of 4.9metres. The A310, A300 and A330 has a diameter of 5.64metres. At 46metres long the 797-8 its not short and stubby either. Its similar to the 767 and 787 models.

RJMAZ - I'm not trying to pick a fight - the work you have done is beautiful.

However On the 6 versus 7 seats - yes the Cabin would be about about 28.5% wider but that is the not the increase in the surface area of the cross section. I and others on here have done the calcs on this forum many times - a 7 seat elipse is only about 18-19% more cross section than an A320 for 16.6% more seats in Y - However in long distance First or Bus lay flat pods you get 50% more seats in 1x1x1 and if it's old style bus class you would get 50% more as well in a 2x2x2 layout. A seven seat Cross section can beat the economics of a 6 seater when you take into account the extra premium seats and the plane would be shorter - the weight penalty may be small as it could be shorter for the same capacity/range. As well the A320 is about 3-4% more cross section than 737 and it doesn't seem to hurt it that much.

Your cross section does not work for an eventual NSA either which would force Boeing to do another Cross Section and have 4 in production at once.

I think if you redraw yours with the LD3-45 properly dimensioned you will see how much wasted space you have in the belly. Redraw it at 7 wide with an LD3-45 and redo your calcs on take-off weights etc.. I think you will see that a 7W works great as well - unless you can get something more than 1x1x1 in the front and 2x2x2 in traditional business class. You may also find that there is not enough luggage capacity with 8W and LD3-45's. 7W might be too much but you would have extra length (versus same capacity 8W) to hold a few more containers.

Keep up the great work.

VS11 wrote:

FlyHappy wrote:

chiki wrote:

Alan Joyce says its a widebody and economics look good

https://www.ausbt.com.au/qantas-eyes-bo ... stic-fleet

Interesting. This is the most definitive statement I've heard from an actual customer that specifically cites the need and the (presumed) solution, in the form we've all speculated about. The fact that Joyce doesn't mention the A321LR at all is another thing... I wonder why?

Because Qantas is not looking for range but for a higher-capacity aircraft that is lighter than B787/A330.

And they aren't the only ones. Add to the low weight the state-of-the-art engines and systems and aerodynamics and a lot of airlines will be interested.

The real question is can Boeing hit ALL the price and performance targets it's setting out for this product?

If not, the competition will be very much ready to pounce.

The range question will be no doubt very interesting with what Boeing come up with. There sure are a hell of a lot of A333 flying high capacity routes in Asia that a Boeing MOM could replace. But doesn't the engineering of the wing for long range add a cost to the airliner that is not needed for short-medium haul operations for which there seems to be a demand? After all, Boeing has not replaced the standard 767-3 or 767-2 and the 757-2 and 757-3 have a limited in service life left and the A300 was never replaced and Airbus never produced a regional A332 if I am not mistaken. All the development has been on long-haul and nothing in high capacity short-medium haul. What's the equation here?

seahawk wrote:

The 797 will sell like hot cakes. QF is making a clear commitment in this interview. I can see Boeing launch with over 500 orders in the books.

500? I wish I shared your enthusiasm.

PlanesNTrains wrote:

seahawk wrote:

The 797 will sell like hot cakes. QF is making a clear commitment in this interview. I can see Boeing launch with over 500 orders in the books.

500? I wish I shared your enthusiasm.

The potential customers I have heard of within the US were not what I expected. Have to wait and see I guess. I do think the market has changed, particularly in Asia, since the days of the 767/757/A300.

FlyHappy wrote:

VS11 wrote:

FlyHappy wrote:

Interesting. This is the most definitive statement I've heard from an actual customer that specifically cites the need and the (presumed) solution, in the form we've all speculated about. The fact that Joyce doesn't mention the A321LR at all is another thing... I wonder why?

Because Qantas is not looking for range but for a higher-capacity aircraft that is lighter than B787/A330.

Indeed, I actually meant A321Neo in 240 pax form (though I realize not necessarily QF desired config).
I also realize the answer to that would be: QF desires more pax in 2 class arrangement, etc.

my question was a touch rhetorical. Seems to me Joyce doesn't see a viable proposed Airbus solution to his MoM need, and so, by extension, I wonder how many other markets see the same.

The Airinsight opinion poll published at the time of the PAS this year suggested that most airlines were interested in range (as in 5000Nm or more) rather than capacity.
If that's the case, QF's position might not necessarily be representative of the larger market.
That said, the poll suggested the biggest criticism of the A321++ was it's lower range compared to the MOM proposals being offered.

Rgds

I imagine that QF is interested in both range and capacity, 3500nm ( closer to realistic A321LR range) may just not provide enough to be of interest to QF. 4500nm (realistic range) vs 3500nm (realistic range) opens up quite a bit of possibilities from various Australian cities.

Revelation wrote:

VS11 wrote:

FlyHappy wrote:

Interesting. This is the most definitive statement I've heard from an actual customer that specifically cites the need and the (presumed) solution, in the form we've all speculated about. The fact that Joyce doesn't mention the A321LR at all is another thing... I wonder why?

Because Qantas is not looking for range but for a higher-capacity aircraft that is lighter than B787/A330.

And they aren't the only ones. Add to the low weight the state-of-the-art engines and systems and aerodynamics and a lot of airlines will be interested.

The real question is can Boeing hit ALL the price and performance targets it's setting out for this product?

If not, the competition will be very much ready to pounce.

On paper it is a compelling aircraft. But if fuel stays cheaper and air travel demand continues to be strong and the pilot shortage exarcebates then by the time the plane is available the airlines will have been deploying the heavier current long-haul planes and might not need the 797 that much.

If Boeing were to design a folding wing for the 797, how expensive would it be to design a second wing option of the same size that doesn't fold?

VS11 wrote:

Revelation wrote:

VS11 wrote:

Because Qantas is not looking for range but for a higher-capacity aircraft that is lighter than B787/A330.

And they aren't the only ones. Add to the low weight the state-of-the-art engines and systems and aerodynamics and a lot of airlines will be interested.

The real question is can Boeing hit ALL the price and performance targets it's setting out for this product?

If not, the competition will be very much ready to pounce.

On paper it is a compelling aircraft. But if fuel stays cheaper and air travel demand continues to be strong and the pilot shortage exarcebates then by the time the plane is available the airlines will have been deploying the heavier current long-haul planes and might not need the 797 that much.

Wouldn't a pilot shortage lead airlines to want to upsize there smallest aircraft? I think they would be more likely to get rid of there Single Aisles and go the 797 route and abuse them on distances under 2,000 NM vs taking a very heavy widebody and doing the same. A 797 should be more efficient than a widebody on short routes, especially if you can pack 260-270 seats in sardine class. If the 797 is somewhere around 70T OEW that's about 270KG per seat at 260 seats. A 787-8 has an OEW of about 120T or about 334KG per seat with a max seating of 359. The 797 should be a lot more efficient.

morrisond wrote:

a 7 seat elipse is only about 18-19% more cross section than an A320 for 16.6% more seats in Y -

Thanks

I don't think a true eclipse will work. But now you are comparing a 7AB oval to a 6AB circle. True you may be able to match the cross section area per seat. This would allow for per seat fuel costs to potentially match the A321 if the range requirements were equal. However once you add 1000+ nm extra range to the MOM the weights go up. It can then no longer match the short range CASM of the A321. This is a critical goal of the program. The biggest market for Boeing is to get airlines to upgauge their narrowbody network. This will hit the larger A321 much harder than the 737.

You should compare an oval 7AB to an oval 8AB. The 8AB has less cross section per passenger. In fact 8AB oval now beats the 737 and A320 families. Now that allows rooms for the extra range to be added.

morrisond wrote:

As well the A320 is about 3-4% more cross section than 737 and it doesn't seem to hurt it that much.

Actually that is the 737's only advantage and the only reason it is still competitive. People know the A320 has bigger engines and a better wing. That Boeing is limited to smaller diameter engines but the smaller, lighter frame makes up for it.

morrisond wrote:

You may also find that there is not enough luggage capacity with 8W and LD3-45's. 7W might be too much but you would have extra length (versus same capacity 8W) to hold a few more containers.

Actually the A321LR has 3 of the 10 container positions filled with fuel tanks. Its also very limited on payload weight when running long range flights.

So an equal cabin length 797-8 would have 10 container positions available. That is 43% extra cargo space than a A321LR using small LD3-45's. The 797-8 being 8 abreast has 33% more seats. So the shortest 797-8 actually has more cargo space per passenger than the A321LR.

The 797 stretch models would have even more cargo space per passenger. Boeing could even design a new container an LD3-45 but without the angles on the bottom. This would also allow for LD8 pallets to fit perfectly.

Boeing might decide that the weight penalties for an oval can't work. A circular fuselage means 8 abreast is a definitely. A foot narrower and shorter than the A330 with slightly narrower LD2 containers.

morrisond wrote:

Wouldn't a pilot shortage lead airlines to want to upsize there smallest aircraft? I think they would be more likely to get rid of there Single Aisles and go the 797 route and abuse them on distances under 2,000 NM vs taking a very heavy widebody and doing the same. A 797 should be more efficient than a widebody on short routes, especially if you can pack 260-270 seats in sardine class. If the 797 is somewhere around 70T OEW that's about 270KG per seat at 260 seats. A 787-8 has an OEW of about 120T or about 334KG per seat with a max seating of 359. The 797 should be a lot more efficient.

The amount of city pairs now served by 10+ narrow body flights per day has doubled in a decade. It is an exponential trend. I predict it to double again in 10 years. Airlines are so desperate that we now have 747's flying 1000nm daily flights on thick routes.

If the MOM is 7AB it is too small to provide a big upgauge. It also won't be quite as efficient and may not match the economics of the 6AB. Airlines may just keep adding narrowbody aircraft instead of bringing in a new aircraft type.

An 8AB will bring a 50-70% upgauge and has a greater chance of matching the per seat economics of the 6AB. The airline industry is a number game. If you have 5% better CASM you don't get 5% more sales you get 500% more sales. That is why 8AB will sell much more.

You are definitely right on the weight of current widebody aircraft. If you have two aircraft with identical cabins and one is designed to fly 7000nm and the other only 3500nm. The shorter range aircraft would weigh two thirds of the weight. It would be burning only two thirds of the fuel per passenger on short routes.

For this reason I wouldn't rule out a significantly lighter and smaller wing 787. Not a 787-3. But one where the wing box, the entire wing, the engines and landing gear are all reduced in size and weight. If the empty weight could be reduced from 120T to below 100T it acheives the goals of the MOM. It also explains the production ramp up.

NYCRuss wrote:

If Boeing were to design a folding wing for the 797, how expensive would it be to design a second wing option of the same size that doesn't fold?

So the solid wing has more room for fuel?

As this looks like it will be a large but short range widebody fuel volume won't be an issue. The wing will be relatively large to lift the large fuselage so there will be plenty of space to have fuel to fly 5000nm even with folding wing tips.

Airports have plenty of code D gates used by the 757 and 767. There would be no need to make folding wing tips to fit smaller code C gates. The gate shortages are for the larger and small gates, not the medium sized gates.

RJMAZ wrote:

morrisond wrote:

a 7 seat elipse is only about 18-19% more cross section than an A320 for 16.6% more seats in Y -

Thanks

I don't think a true eclipse will work. But now you are comparing a 7AB oval to a 6AB circle. True you may be able to match the cross section area per seat. This would allow for per seat fuel costs to potentially match the A321 if the range requirements were equal. However once you add 1000+ nm extra range to the MOM the weights go up. It can then no longer match the short range CASM of the A321. This is a critical goal of the program. The biggest market for Boeing is to get airlines to upgauge their narrowbody network. This will hit the larger A321 much harder than the 737.

You should compare an oval 7AB to an oval 8AB. The 8AB has less cross section per passenger. In fact 8AB oval now beats the 737 and A320 families. Now that allows rooms for the extra range to be added.
....
Boeing might decide that the weight penalties for an oval can't work. A circular fuselage means 8 abreast is a definitely. A foot narrower and shorter than the A330 with slightly narrower LD2 containers.

I've done my calcs in the past based on ellipses as a simple approximation, but I expect you're right about the double bubble. The possible advantage of an ellipse (or perhaps elliptical double bubble) is the ability to locate the maximum width closer to shoulder height, but obviously with the disadvantage of bending loads on the fuselage frames.

I'm still trying to convince myself the concept will go as far as 8 abreast, but I do recognize the quantitative point you're making.

I haven't looked in detail at how the circular vs. widened 7 or 8 abreast shapes compare, but given a rough idea what a low proportion of the overall weight the frames and floorbeams are, vs. how much the area and circumference increase with circular (which restores at least some of that weight), I'm increasingly expecting the ultimate design will be some form of widened oval.

It will be very interesting to see details of this program come out if it becomes a reality.

Given the Bombardier/Airbus announcement of a partnership on the C-Series - this may cause Boeing to due some new calculus on the MOM.

I would guess Airbus expands the CS to 500 and 700 versions possibly with a new wing which allows them to focus on the A320/A321 size and either speed up a rewing in 321/322 lengths or something clean sheet.

If it was cleansheet and they went 2x3x2, they could put a bullet in the 330 and then have very efficient 5W,7W and 9W cross sections.

This would definitely force Boeing into 7w or even 6w if they wanted to compete across the whole size range. In reality they may be forced to do two different fuselage widths ala 757/767 and then maybe they do go 8w on MOM and due a pure 6W NSA.

Anyway I think this kills Boeing unveiling MOM anytime soon.

Hurry up and wait.

I

airtechy wrote:

It's very simple. You re-design the 757 in plastic, upgrade the engines and avionics, add FBW and you're done.

Redesign the airplane in Aluminum-Lithium upgrade the engine controls to FBW and redesign the flight controls to "ALL Digital" (not just FBW)
(No follow-up cables what so ever on ANY Axis) to the capability of the B787-8.
Upgrade the comm to all digital where even the flight plans are uploaded with NO Pilot input. Then? You've got a winner of an airplane!!

morrisond wrote:

Given the Bombardier/Airbus announcement of a partnership on the C-Series - this may cause Boeing to due some new calculus on the MOM.

I would guess Airbus expands the CS to 500 and 700 versions possibly with a new wing which allows them to focus on the A320/A321 size and either speed up a rewing in 321/322 lengths or something clean sheet.

I think this further increases the chance of an 8AB mom.

The A320 family would eventually get a carbon fibre wing in 10-15 years time. Now this wing could be made slightly larger and more capable. It will no longer have to be sized to take into account the shorter A320.

The A321 rewinged would have a better lift to drag ratio and a lower fuel burn per seat. With the extra fuel volume in the wings the fuselage tanks are removed. The A322 then provides even better fuel burn per seat. Better fuel burn per seat and lower weight per seat than the 7 abreast Boeing MOM. The 8 abreast MOM from Boeing is the only way to compete with such a plane in 20 years time.

Still feeling a 3 model single aisle design.

225 pax, 5700 nm range
250 pax, 4700 nm range.
275 pax at 4000 nm range.

Allows up guage on sub 4k routes served by A321s and 757-200s.
Opens up long and thin routes. New options for routes that may have been too expensive to send a wide body.

RJMAZ wrote:

c933103 wrote:

That would probably be too much capacity to what have been proposed, hence most likely it won't go to 8-abreast, and could instead be 7-abreast. As a widebody it could also start at a length shorter than A321

7 abreast can't match the economics of a 6 abreast.

Assuming 18inch seats and 18inch aisles.

6 abreast is 126inch wide cabin.

7 abreast is 162inch wide cabin. That is 28.5% wider for only 16.6% more seats. 28.5 is 72% greater than 16.5.

8 abreast is 180ich wide cabin that is 42.8% wider for 33.3% more seats. 42.8 is only 28% greater than 33.3

This should hopefully end any rumours of a 7 abreast.

The efficiency target of the mom has to be extremely high. If it can't match the narrow bodies on short routes it won't sell. If it can't match a 787 on medium haul routes it won't sell. The only way this is achievable is with 8 abreast.

My reduced height double bubble fuselage has an average diameter of 4.9metres. The A310, A300 and A330 has a diameter of 5.64metres. At 46metres long the 797-8 its not short and stubby either. Its similar to the 767 and 787 models.

Consider keeping same cabin height as a narrowbody in a 7-ab design?

Elementalism wrote:

Still feeling a 3 model single aisle design.

225 pax, 5700 nm range
250 pax, 4700 nm range.
275 pax at 4000 nm range.

Allows up guage on sub 4k routes served by A321s and 757-200s.
Opens up long and thin routes. New options for routes that may have been too expensive to send a wide body.

I guess I'm one of the lone voices that also sees a narrowbody, not a widebody. I'd look for a "757-250" if you will; higher capacity and range than the 752, not quite the capacity of the 753, though. A 4700nm, 225-245 seat aircraft feels about right to me in this space.

A two aisle plane has an inherent comfort level over a single aisle plane, and that level of comfort get a lot higher as the passenger load increases. Besides loading and unloading being easier, bathrooms are more accessible as no one has to crawl over two people, there are more desirable seats. My suspicion is that airlines will be able to charge a little more for flying in two aisle, and especially those who are familiar with what plane they are flying will happily pay that $25 or so.

frmrCapCadet wrote:

My suspicion is that airlines will be able to charge a little more for flying in two aisle, and especially those who are familiar with what plane they are flying will happily pay that $25 or so.

Respectfully, airlines aren't able to charge more just based on whether or not a widebody or narrowbody is offered on a given route; if your competitor charges $10 less, they'll earn the business before you, regardless of equipment. And "those who are familiar" with the type flown are such a small percentage of total passengers that it would be irresponsible for a carrier to bank on those customers being willing to pay more when justifying the use of a particular type.

EA CO AS wrote:

I guess I'm one of the lone voices that also sees a narrowbody, not a widebody. I'd look for a "757-250" if you will; higher capacity and range than the 752, not quite the capacity of the 753, though. A 4700nm, 225-245 seat aircraft feels about right to me in this space.

The reason everyone is seeing a widebody is that recent murmurs (e.g. QF's Alan Joyce the other day) are that Boeing is presenting/floating a twin aisle aircraft for the segment that they (Boeing) claim will have competitive economics with a comparable narrowbody (and airlines have said look compelling on paper).

EA CO AS wrote:

Elementalism wrote:

Still feeling a 3 model single aisle design.

225 pax, 5700 nm range
250 pax, 4700 nm range.
275 pax at 4000 nm range.

Allows up guage on sub 4k routes served by A321s and 757-200s.
Opens up long and thin routes. New options for routes that may have been too expensive to send a wide body.

I guess I'm one of the lone voices that also sees a narrowbody, not a widebody. I'd look for a "757-250" if you will; higher capacity and range than the 752, not quite the capacity of the 753, though. A 4700nm, 225-245 seat aircraft feels about right to me in this space.

Could be but Boeing has publicly stated the airilnes do not want a single body but a widebody. A business that ignores its customer's wishes do so at its own peril.

Has anyone done a study of the economics of reducing turn time, especially for short segment flights. I seem to remember a time when WN stated that their quicker turn times saved them 11 aircraft.

For WN, here are some statements from the company

In 2016, the Company’s average aircraft trip length was 760 miles with an average duration of two hours and three minutes.
In 2016, Southwest aircraft flew an average of nearly five flights or about 11 hours per day.

Their turn times used to be 20 minutes ! If they could save 20 minutes off the current turn time, they would save 80 to 100 minutes a day. That could reduce their fleet size by more than 10%. So superficially a twin aisle could be some combination of up to 10% more expensive or 10% less fuel efficient.

On top of that there would be less maintenance, shorter crew times, less gates, etc etc.

chiki wrote:

Alan Joyce says its a widebody and economics look good

https://www.ausbt.com.au/qantas-eyes-bo ... stic-fleet

When he says a "transcontinental jet" what range is he referring to? A domestic or regional widebody with excellent economics has the makings of a best seller.

We repeatedly hear that people will not pay more for a better flight experience. It is one of the biggest aviation myths of all time. The reality is that unless someone is really knowledgeable about what they are getting they are as likely to have a miserable flight as a good one. People do not go to Econo, Motel 8s or 6s accidentally. Many pay for a little or a lot more expensive ones. They know that what they get is based in large part by what they pay. Sooner or later, I hope sooner, Orbitz and others will rate the comfort and level of service someone gets when they buy a flight. I can assure about everyone that people will pay a hell of a lot more for a more comfortable flight. And airlines will then start offering them. And some airlines and or some of their seats will be cheaper and customers will expect less.

380s are known for their comfort, and I understand that they attract fliers at higher prices.

8Y is more efficient than 7Y, 9Y more than 8, 10 more than 9.

So why not just a 10Y that's super short? Obviously that makes no sense. But that's my point.

Everyone who is dismissing 7Y is ignoring that a short and fat aircraft has efficiency issues of its own, and has poor cargo capacity as a ratio to pax capacity. If the 797 is supposed to be a 757/763 sized aircraft it can't be 8Y and meet all the mission objectives. It will either be too short or too high capacity.

Then there's the problem of ld3-45 fixation. LD3-45 is NOT something to aspire to in a wide body. It's small. Too small. It's nice Airbus found a way to containerize an A320 and create a false perception that it's standard by using the name LD3 when it's anything but, but a 767 carries nearly twice the cargo per container space and can interchange full height pallets with larger wide bodies. The 797 MUST be capable of this.

william wrote:

When he says a "transcontinental jet" what range is he referring to? A domestic or regional widebody with excellent economics has the makings of a best seller.

The more an aircraft is optimised for short range the better the economics on short flights.

If you halved the range requirement and fully optimised it the aircraft would probably end up being two thirds of the weight. That's a big fuel burn saving simply by reducing the range.

Some people think the MOM will be built for long thin routes around 5000nm. They think a carbon fibre 757 would be perfect.

Myself and others think it will be built to upgauge thick routes under 2000nm. So it will be big but very light for its size. Think a carbon fibre A300.

The longer version of the family I wouldn't be surprised if its range is less than 3500nm. The shorter version slightly above 4500nm is all that is required. That's because I don't believe a MOM designrd for long thin routes could be competitive.

I think a 2-4-2 flat MoM would be competing against similar capacity 2-4-2 aircraft that can carry full size LD3's and cargo palllets from the top.

https://pbs.twimg.com/media/DL3Vt-eWkAIfInp.jpg

and narrowbody 3-3 aircraft that cost much less, have decent capacity and weigh 15t less. But still do 4500NM.

https://lh3.googleusercontent.com/-YckgYMk2UT4/WefZgFfVq_I/AAAAAAAADOA/KMkNbbEqJlIBKx_4eBuQpO83oWAH-USwQCLcBGAs/s1600/A360-900.jpg

That seems a risky route to recoup development and make profits.

As expected by me and many others, Boeing's MAX isn't good enough for 2030.

Boeing's NMA might shrink considerably in the next 6 months.

RobertPhoenix wrote:

Has anyone done a study of the economics of reducing turn time, especially for short segment flights. I seem to remember a time when WN stated that their quicker turn times saved them 11 aircraft.

For WN, here are some statements from the company

In 2016, the Company’s average aircraft trip length was 760 miles with an average duration of two hours and three minutes.
In 2016, Southwest aircraft flew an average of nearly five flights or about 11 hours per day.

Their turn times used to be 20 minutes ! If they could save 20 minutes off the current turn time, they would save 80 to 100 minutes a day. That could reduce their fleet size by more than 10%. So superficially a twin aisle could be some combination of up to 10% more expensive or 10% less fuel efficient.

On top of that there would be less maintenance, shorter crew times, less gates, etc etc.

I think the idea of the MoM is for longer routes. 3500-5000km. Saving 20 minutes on a 7-10 hour flight means a lot less than on a 2 hour flight. These planes take 30-45 mins to fuel.

I see claims of shorter range than I would optimize for with a modern wing. The MoM will have lower wing loading than the MAX or NEO. That is pretty much a given. The engine will be more optimized for 5+ hour missions (fewer cycles between overhauls).

keesje wrote:

Boeing's NMA might shrink considerably in the next 6 months.

Shrink or grow, doesn't matter much. The reality is for missions of 5+ hours, none of the narrowbodies out there have a modern wing. There is just too much low hanging fruit with a modern CFRP, or maybe even GFRP wing. Add in folding wingtips to get back into a small parking spot, and we're talking a winner.

It will either be a 2-4-2 widebody or 3-3 narrowbody. Sorry 767 fans, but 2-3-2 is just too much wasted space & weight verus a 3-3 configuration. I do not see another 3-3-3 of the 787. This will be a narrower plane. but how narrow? How much is cargo worth?

We're exiting the fan stage and going to the 'what customers will pay for' stage. I'm not sure which cross section. 2-4-2 or 3-3... Probably the former to increase capacity. Either way, the program seems to be moving forward...

Lightsaber

keesje wrote:

I think a 2-4-2 flat MoM would be competing against similar capacity 2-4-2 aircraft that can carry full size LD3's and cargo palllets from the top.

https://pbs.twimg.com/media/DL3Vt-eWkAIfInp.jpg

and narrowbody 3-3 aircraft that cost much less, have decent capacity and weigh 15t less. But still do 4500NM.

https://lh3.googleusercontent.com/-YckgYMk2UT4/WefZgFfVq_I/AAAAAAAADOA/KMkNbbEqJlIBKx_4eBuQpO83oWAH-USwQCLcBGAs/s1600/A360-900.jpg

That seems a risky route to recoup development and make profits.

As expected by me and many others, Boeing's MAX isn't good enough for 2030.

Boeing's NMA might shrink considerably in the next 6 months.

For the uptemth time the airline have said they want a widebody.

FlyHappy wrote:

chiki wrote:

Alan Joyce says its a widebody and economics look good

https://www.ausbt.com.au/qantas-eyes-bo ... stic-fleet

Interesting. This is the most definitive statement I've heard from an actual customer that specifically cites the need and the (presumed) solution, in the form we've all speculated about. The fact that Joyce doesn't mention the A321LR at all is another thing... I wonder why?

Probably the need for a small wide-body for transcontinental domestic operations (i.e., PER to SYD or PER to MEL) or I would imagine even PER to AKL. Wasn't that the domain of the 767 for a long time for QF? For QF, I would imagine the ability to accept the LD3 ULD would also be important.

keesje wrote:

arrowbody 3-3 aircraft that cost much less, have decent capacity and weigh 15t less. But still do 4500NM.

How did you come to the 3-3 weighing 15T less?

A300 cabin area 215m2 OEW 88T
That's 2.44square metres of cabin area per ton

757-200 cabin area 127m2 OEW 58T
That's only 2.14 square metres of cabin area per ton.

The range of both aircraft are identical.
2-4-2 is lighter than 3-3 in the 200+ seat market.

Most widebody aircraft are heavier due to their massive fuel capacity for long range flight.

The A300 is the only widebody ever built for regional work. So this is the only aircraft you should use to compare MOM widebody weights.

The A300 even matches the latest A321 for cabin area per ton.

The MOM will be 2-4-2

aemoreira1981 wrote:

Probably the need for a small wide-body for transcontinental domestic operations (i.e., PER to SYD or PER to MEL) or I would imagine even PER to AKL. Wasn't that the domain of the 767 for a long time for QF? For QF, I would imagine the ability to accept the LD3 ULD would also be important.

The A330's fairly wide 8 abreast and the 787's tight 9 abreast is as narrow as you can go with LD3 containers. The A330 makes a massive compromise to fit the LD3's, its cabin floor level has to be fairly so the fuselage narrows significantly at shoulder height.

The only option with a tight 8 abreast is to use LD2's. Being a bit narrower the container can sit slightly lower down.

william wrote:

keesje wrote:

I think a 2-4-2 flat MoM would be competing against similar capacity 2-4-2 aircraft that can carry full size LD3's and cargo palllets from the top.

https://pbs.twimg.com/media/DL3Vt-eWkAIfInp.jpg

and narrowbody 3-3 aircraft that cost much less, have decent capacity and weigh 15t less. But still do 4500NM.

https://lh3.googleusercontent.com/-YckgYMk2UT4/WefZgFfVq_I/AAAAAAAADOA/KMkNbbEqJlIBKx_4eBuQpO83oWAH-USwQCLcBGAs/s1600/A360-900.jpg

That seems a risky route to recoup development and make profits.

As expected by me and many others, Boeing's MAX isn't good enough for 2030.

Boeing's NMA might shrink considerably in the next 6 months.

For the uptemth time the airline have said they want a widebody.

Market requirements are for certain capacity and pay load range at minimum costs and whatever configuration meets those requirements.

If the requirements is e.g. 260 single class, 8 abreast means around 32 seat rows. Like a 737-8 cabin lenght.. Technical miracles are required to make take competitive.

Technical miracles are not there. Going longer you get into 300-400 seats single class, incapable of LD3/pallets and flights from Asia. A small niche.

To small for Collin Stuart and his mates 17 years ago. Maybe times have changed. But OE are conservative,,

https://www.flightglobal.com/news/articles/airbus-rethinks-250-seater-to-keep-a330-commonality--65324/

That plane would not even be able to take the luggage from the pax in a eco heavy configuration. And if you start hand loading the baggage, the fast turn around promised by the twin aisle is gone.