Boeing unveils new version of radical wing design

texl1649 · Fri Jan 11, 2019 8:15 pm

The technological maturity level of the folding (carbon) wings, Avios (GE) gearbox, carbon fuselages, and some braced strut systems will indeed all be critical to the future NSA, but none of it IMHO will be too easy to extrapolate from this until we see how the flight control systems, and frames for the NMA are finally confirmed/revealed to the public.

I'm sure there is an intent to make sure no A32x can really touch the next generation, but rather the goal is to just advance toward a system of suppliers, support, and IP rights to ensure it can't be easily copied (including an exclusive on engines, if I had to guess).

seabosdca · Fri Jan 11, 2019 8:27 pm

This design will have an issue common to all high-wing passenger aircraft: where do you store carry-ons for passengers sitting directly under the wing box? Also, for a narrowbody, how do you ensure there is enough headroom in the aisle under the wing box for passengers to walk safely?

That said, those wings would be groundbreaking and I have no doubt that they and the larger fans they enable would together save enough fuel to be worthwhile, even after taking into account the additional structural weight needed for a T-tail and what amounts to a second wing spar.

SheikhDjibouti · Fri Jan 11, 2019 9:34 pm

seabosdca wrote:
This design will have an issue common to all high-wing passenger aircraft: where do you store carry-ons for passengers sitting directly under the wing box? Also, for a narrowbody, how do you ensure there is enough headroom in the aisle under the wing box for passengers to walk safely?

I suggest Boeing ask the designers of the BAe146 and An-148 for their ideas on that. I've googled dozens of interior images of both a/c and haven't identified any obvious intrusion or lack of roof space (beyond the fact that both designs are a little cramped compared to more familiar A & B offerings)
If the pax sitting in the rows beneath the wing have to drop their carry-ons further along the plane, maybe those seats can be sold at a slight discount. Or offered a free allowance for hold luggage.
You are correct it might be an issue, but easily solved in a variety of ways.

seabosdca wrote:
That said, those wings would be groundbreaking…. even after taking into account the additional structural weight needed for .... what amounts to a second wing spar.

If the lower truss is indeed a second wing offering real lift (and associated drag), then maybe so. If they are simply supporting struts, probably not.
My own thoughts are they are probably halfway between the two, unlike the Short SD3-30

I'm more reminded of this; not quite a full width biplane, and definitely not a monoplane.

Just swap out those old radial engines for a pair of CFM LEAPS, et volià, we're good to go. :bigthumbsup:

Planeflyer · Fri Jan 11, 2019 10:55 pm

parapente wrote:
I think there are those who just love the status quo - bring back the 757!

The idea that Boeing engineers just ignore all the practical aspects of commercial aircaft is simply ludicrous.
Of course this design does show how hard it's getting to improve.This is how far you clearly need to go to get an additional 8-10% saving.
( at the accepted commercial cruising speed - slower would be too easy!).
Nothing's going to happen for 5-10 years anyway but good that they are exploring all the avenues.Wonder what Airbus' guys/ girls think the next step might be?

Agree, critics never built anything.

QuarkFly · Sat Jan 12, 2019 7:00 am

SheikhDjibouti wrote:
QuarkFly wrote:
But, once an airliner is at cruise speed and altitude, most drag is coming from skin friction, over half, and this design won't help -- it could make it worse with the lower support struts.
Quick, somebody e-mail the chumps at Boeing - they must have somehow overlooked this aspect of the design.....

QuarkFly wrote:
The high mounted engines would allow larger bypass ratios...but for maintenance, now you have to work at least five meters in the air to get at the engines

Five meters? I guess you mean like these poor souls..

... [MD- 80 and engine pics] ...

Wow, it's funny how these platforms and ladders don't look anywhere near that height, unless you are working on the top-side of the engine. Perhaps the maint men working on them are all 12' tall?
And yet somehow for years they managed.
Go on, tell me the engines on an MD-80 are totally different and not at the same height - I dare you!
...

I fail to see how any of your points about this post's new aircraft architecture are relevant for anything other than snark.

I appreciate DC-9 / MD-80 engine maintenance personnel as much as anybody....but their many years of service is unlikely to help bring this new high-wing with truss architecture into airliner service anytime in the future. -- Other than, as I mentioned, maybe a replacement for smaller ATR or Q400 sized aircraft.

ELBOB · Sat Jan 12, 2019 8:03 am

SheikhDjibouti wrote:
My own thoughts are they are probably halfway between the two, unlike the Short SD3-30

I'm not sure what you mean in terms of the 330, but the struts were absolutely part of the overall lift caculation; that went back to the original Hurel-Dubois concept. As was the fuselage itself, which was a form of lifting-body; I can't remember the exact figure but something like 15%-20% of the lift at cruising speed was generated by the fuselage.

No doubt Boeing will someday produce a CGI render of a lifting-body airliner and the fanboys will cheer about how 'radical' and 'groundbreaking' it is...

SheikhDjibouti · Sat Jan 12, 2019 12:23 pm

ELBOB wrote:
SheikhDjibouti wrote:
My own thoughts are they are probably halfway between the two, unlike the Short SD3-30

I'm not sure what you mean in terms of the 330, but the struts were absolutely part of the overall lift caculation; that went back to the original Hurel-Dubois concept. As was the fuselage itself, which was a form of lifting-body; I can't remember the exact figure but something like 15%-20% of the lift at cruising speed was generated by the fuselage.

No doubt Boeing will someday produce a CGI render of a lifting-body airliner and the fanboys will cheer about how 'radical' and 'groundbreaking' it is...

Yes, you are spot on, and I used entirely the wrong words there. (It was late, I was tired...)
It also would have helped if I had selected a different photo for the 330, to emphasize the struts, not de-emphasize them.
How about this one instead.

The issue of the fuselage contributing lift is another aspect, and can be found in seemingly less obvious cases.

Wikipedia wrote:
Piaggio claims that the fuselage contributes up to 20% of the Avanti's total lift,

Coming back to the Boeing proposal, and Hurel-Dubois; another very early incarnation was the Miles M.57 Aerovan.
Here are standard production M.57 with the original 50ft wingspan (no struts)

Here is the same fuselage, with a much larger 75 ft Hurel-Dubois designed wing including struts.
Disappointingly, I believe the performance was more or less unchanged. :cry:

In basic terms, both of them could be overtaken by a man on a bicycle....

Note also the unusual registration (G-AHDM), previously worn by a HP.57 Halifax, and selected to recognise the new designation (this M.57 was re-designated HDM.105)

BAeRJ100 · Sat Jan 12, 2019 12:44 pm

SheikhDjibouti wrote:
seabosdca wrote:
This design will have an issue common to all high-wing passenger aircraft: where do you store carry-ons for passengers sitting directly under the wing box? Also, for a narrowbody, how do you ensure there is enough headroom in the aisle under the wing box for passengers to walk safely?
I suggest Boeing ask the designers of the BAe146 and An-148 for their ideas on that. I've googled dozens of interior images of both a/c and haven't identified any obvious intrusion or lack of roof space (beyond the fact that both designs are a little cramped compared to more familiar A & B offerings)
If the pax sitting in the rows beneath the wing have to drop their carry-ons further along the plane, maybe those seats can be sold at a slight discount. Or offered a free allowance for hold luggage.
You are correct it might be an issue, but easily solved in a variety of ways.

The 146 has a very obvious drop in the middle of the cabin that extends for around 2 to 3 rows, the o/head bins in this area are about half the height of the rest. Good enough to store a laptop bag and nothing more.

bigjku · Sat Jan 12, 2019 1:46 pm

BAeRJ100 wrote:
SheikhDjibouti wrote:
seabosdca wrote:
This design will have an issue common to all high-wing passenger aircraft: where do you store carry-ons for passengers sitting directly under the wing box? Also, for a narrowbody, how do you ensure there is enough headroom in the aisle under the wing box for passengers to walk safely?
I suggest Boeing ask the designers of the BAe146 and An-148 for their ideas on that. I've googled dozens of interior images of both a/c and haven't identified any obvious intrusion or lack of roof space (beyond the fact that both designs are a little cramped compared to more familiar A & B offerings)
If the pax sitting in the rows beneath the wing have to drop their carry-ons further along the plane, maybe those seats can be sold at a slight discount. Or offered a free allowance for hold luggage.
You are correct it might be an issue, but easily solved in a variety of ways.

The 146 has a very obvious drop in the middle of the cabin that extends for around 2 to 3 rows, the o/head bins in this area are about half the height of the rest. Good enough to store a laptop bag and nothing more.

Seems like a flattened oval fuselage might help with this issue.

parapente · Sat Jan 12, 2019 1:57 pm

If they are serious about this proposal -long term and I imagine they might be ,unless one is being highly cynical. It is a good idea to keep publicising refinements.This is obviously the second major release.
On the basis that the MOM comes first they have 7-10 years to refine it.Each time they 'go public' it will give them an opportunity to see what consumer reaction is to it.Indeed get the flying public used to something that 'looks' different.
Go back 50 years and there were all sorts of different designs so consumers embraced change.But there hasn't been anything that looks really different for quite a while so consumers may have become like ANet -very conservative!

william · Sat Jan 12, 2019 2:19 pm

bigjku wrote:
BAeRJ100 wrote:
SheikhDjibouti wrote:
I suggest Boeing ask the designers of the BAe146 and An-148 for their ideas on that. I've googled dozens of interior images of both a/c and haven't identified any obvious intrusion or lack of roof space (beyond the fact that both designs are a little cramped compared to more familiar A & B offerings)
If the pax sitting in the rows beneath the wing have to drop their carry-ons further along the plane, maybe those seats can be sold at a slight discount. Or offered a free allowance for hold luggage.
You are correct it might be an issue, but easily solved in a variety of ways.

The 146 has a very obvious drop in the middle of the cabin that extends for around 2 to 3 rows, the o/head bins in this area are about half the height of the rest. Good enough to store a laptop bag and nothing more.

Seems like a flattened oval fuselage might help with this issue.

DfwRevolution · Sat Jan 12, 2019 2:39 pm

SheikhDjibouti wrote:
seabosdca wrote:
This design will have an issue common to all high-wing passenger aircraft: where do you store carry-ons for passengers sitting directly under the wing box? Also, for a narrowbody, how do you ensure there is enough headroom in the aisle under the wing box for passengers to walk safely?
I suggest Boeing ask the designers of the BAe146 and An-148 for their ideas on that. I've googled dozens of interior images of both a/c and haven't identified any obvious intrusion or lack of roof space (beyond the fact that both designs are a little cramped compared to more familiar A & B offerings)
If the pax sitting in the rows beneath the wing have to drop their carry-ons further along the plane, maybe those seats can be sold at a slight discount. Or offered a free allowance for hold luggage.
You are correct it might be an issue, but easily solved in a variety of ways.

I've flown on plenty of A320 and 737 where various overhead bins were blocked for crew bags or equipment.

In fact, on the LUS A321, a few overhead bins in the vicinity of the L2/R2 door are blocked for some kind of equipment and you can't have belongings on the floor due to the emergency exit. Despite the inevitable dearth of overhead bin storage, those seats are sold at a premium!

SheikhDjibouti · Sat Jan 12, 2019 3:05 pm

SheikhDjibouti wrote:
seabosdca wrote:
This design will have an issue common to all high-wing passenger aircraft: where do you store carry-ons for passengers sitting directly under the wing box? Also, for a narrowbody, how do you ensure there is enough headroom in the aisle under the wing box for passengers to walk safely?

I suggest Boeing ask the designers of the BAe146 and An-148 for their ideas on that.

BAeRJ100 wrote:
The 146 has a very obvious drop in the middle of the cabin that extends for around 2 to 3 rows, the o/head bins in this area are about half the height of the rest. Good enough to store a laptop bag and nothing more.

Thanks - that is exactly the clarification I needed. Pax with just a laptop, or a large purse, will be happy to be offered these rows at check-in when the desk clerk sees they are lightly loaded and offers them these seats together with a free drink on-board...

Knowing the HS146 design as you do, can you also comment on the An-148? It appears as if the wing is perched somewhat above the fuselage, rather than running through it as with the HS146/Avro RJ. This would limit wing-box intrusion into the passenger cabin, but clearly this comes with it's own cost, i.e. drag.

DfwRevolution wrote:
I've flown on plenty of A320 and 737 where various overhead bins were blocked for crew bags or equipment.

In fact, on the LUS A321, a few overhead bins in the vicinity of the L2/R2 door are blocked for some kind of equipment and you can't have belongings on the floor due to the emergency exit. Despite the inevitable dearth of overhead bin storage, those seats are sold at a premium!

Yes, I'd completely forgotten the various occasions when "my" overhead locker was already occupied by company equipment. :banghead:

kitplane01 · Sun Jan 13, 2019 6:06 am

Technical questions ...

1) The struts look airfoil shaped. On smaller aircraft one uses the smallest physically reasonable strut, because an airfoil shaped strut produces an excess of drag compared to lift. Are the struts large because they are so worried about flutter on the wing, and so want to attach to both the fore and aft portions of the wing? Or are aerodynamics such that the lift is worth the drag? Or something else?

2) Will the wing have flaps and slats? Will they be as complex as current airliners? Almost all airliners do, but the span loading of this airplane is quite different. Avoiding slats/flaps would be an advantage.

3) What altitude will this fly at? The paper does not say, nor does the SUGAR documents. But it's unlikely to be optimized for the same conditions as a 737 since it's so different than a 737.

kitplane01 · Sun Jan 13, 2019 6:07 am

1989worstyear wrote:
kitplane01 wrote:
lightsaber wrote:
New subsystems on a 737 would bring a 3% improvement.

That conventional replacement doesn't have a CFRP wing. I consider folding wingtips a given to enable more underside laminar flow for another 3% improvement beyond the aspect ratio improvement.

Lightsaber

Boy, there is a lot to unpack there.

Can you explain how improves subsystems might get a 3% improvement? It's really not obvious.

And why do you think the NSA would have a metal wing? I don't think Boeing has ever said that (but I could be wrong). Isn't the A220 wing composite, and the 787. It's well within state of the art.

The mostly Al A320 wing hasn't changed in 30 years - and is still considered the best currently available (despite offering the best in Al alloys 1988 had to offer).

I don't see the current NB designs going away within my lifetime - not enough incentive and not enough innovation following the '87-88 peak.

I don't know why you think the A320 wing is the best. I would imagine the A220 and the 787 were both better. The A320 wing is very span constricted.

aw70 · Sun Jan 13, 2019 7:06 am

What surprises me most about the braced NASA / Boeing design is the fact that they deem it worthwhile to attach struts to the thing. Sure, these allow them to make the main wing thinner and lighter. But the attachment point of the struts to the main wing also creates a really nasty interference point: and optimising the shape of that spot is only going to be really possible for a particular speed and AOA. Seems to be worth it, apparently - but the rest of the wing must be really great, to make this pay off.

seabosdca · Sun Jan 13, 2019 7:12 am

kitplane01 wrote:
I don't know why you think the A320 wing is the best. I would imagine the A220 and the 787 were both better. The A320 wing is very span constricted.

That poster's gimmick is to claim that nothing has improved in commercial aviation, or at least narrowbodies, since the day the A320 entered service.

In the real world, it's not even true in the A320's market segment. The 737NG wing was all-new and developed a decade after that of the A320, and it's one of the two reasons (the other being weight) why the 737 stayed competitive despite its other disadvantages.

parapente · Sun Jan 13, 2019 12:05 pm

Re aw70. I get the impression ( that's all) that the strut and it's wing join is wht this Mk2 version is all about.As you and others state the strut and join are nasty drag areas ( more if the strut gives lift ie foil but this is not stated and cnnot be dummies really as it would be low quality l/d lift compared to the main wing).But yes having the downside of a strut and therefor a top mounted wing must offer better overall economics that alternatives.
The obvious alternative comparison would be a conventionally positioned wing but hinged with the best aspect ration possible that did not require a strut.
They just must have computer tested this route - it's just so obvious.So we can assume that this (Sugar) is the very best layout that they can come up with for optimum l/d.

neutrino · Sun Jan 13, 2019 12:18 pm

seabosdca wrote:
kitplane01 wrote:
I don't know why you think the A320 wing is the best. I would imagine the A220 and the 787 were both better. The A320 wing is very span constricted.

That poster's gimmick is to claim that nothing has improved in commercial aviation, or at least narrowbodies, since the day the A320 entered service.

In the real world, it's not even true in the A320's market segment. The 737NG wing was all-new and developed a decade after that of the A320, and it's one of the two reasons (the other being weight) why the 737 stayed competitive despite its other disadvantages.

Be nice.

Why let facts shatter a fan's fantasies. Reality is poison for some folks.

parapente · Sun Jan 13, 2019 3:12 pm

https://thepointsguy.com/news/the-futur ... ng-design/

Some other nice images from different angles in this piece.
There are quite a few different articles on the web from the last 10 years on this exact programme.Some jet some prop some hybrid etc.I didn't realise that this version is designed to fly even faster than 'standard' LR jets. Such as 787. Can't see the point.But clearly it would be able to fit in with all 'normal' ops of today's aircraft.
All state it would be a folding wing so could fit into std NB gates. So 777x work is clearly critical.
Apparently this model' is based around being a 150 seater but imagine that if it were to ever go commercial it would need to offer a 200 seat option and perhaps even a 250 pax by then.Some put EIS as. Far out as 2035 as a replacement for the 737 ( which would be 75 years old by then!). Think 'something' will happen before then,whatever it is. Perhaps in a decade ( 2030).
The additional images certainly show the revised and increased wing sweep.

Bobloblaw · Sun Jan 13, 2019 3:58 pm

“”“The design standard will apply to new aircraft from 2020 and also to deliveries of aircraft already in production from 2023.””

What does this mean exactly? For currently lines of production? Does a Max8 delivered in 2023 have to be substantially different from one in 2022?

SheikhDjibouti · Sun Jan 13, 2019 4:23 pm

parapente wrote:
https://thepointsguy.com/news/the-future-of-flight-boeing-reveals-concept-aircraft-with-transonic-wing-design/

Some other nice images from different angles in this piece.

Indeed, although the size of that model is somewhat underwhelming; it doesn't exactly suggest this is a high-profile project with a big budget. :cry:

However, it does answer two questions.
1) the wing protrudes slightly above the fuselage, meaning that the wing-box intrudes slightly less into the passenger cabin (see An-148 photo above for example)

2) the struts exit the fuselage at 90° angles, i.e. mostly following behind the swept wing
Maybe this is the secret to reducing interference between the two airfoils?

parapente wrote:
I didn't realise that this version is designed to fly even faster than 'standard' LR jets. Such as 787. Can't see the point.

Unfortunately you probably assumed the writer of that article knew what he was talking about. Big mistake.

The Points Guy wrote:
The speed at which it would reach its best fuel efficiency is Mach .80, or 613 mph — approaching the speed of sound (Mach 1).
For comparison, a Boeing 787s cruising speed is 561 mph

I don't have a degree in either Physiks or Aeronautics, but that just screamed "schoolboy error".

Firstly, Mach 0.80 is only equivalent to 613mph at sea level, whereas at FL400 it's more like 530 mph
Boeing 787 specs make this clear when they cite cruise at Mach 0.85, which fits in nicely at 561 mph (488 knots)
i.e. he made an incorrect comparison, and unfortunately you bought the figures.

But it wasn't all bad - the extra pics were worth a view. :bigthumbsup:

parapente · Sun Jan 13, 2019 4:48 pm

No it's definitely not 'high priority ' right now.Thats MOM ( in the NPD area).And yes 'take your point ! Probably just school boy error - best left as this concept will integrate with other conventional aircraft.
The big bit missing imho is what a conventional 'new' NSA could do ( be)?
Ie how far could an conventional low wing carbon fibre folding wing be stretched ( aspect ratio) without needing to go 'high wing and struts '.What would the performance differential be I wonder?
its no good imho saying this is 10% better than today.Its how it stacks up against a 'tomorrow' wing.One assumes 'still very well' or they wouldn't be wasting their time,but none the less that's the correct comparison.

DigitalSea · Sun Jan 13, 2019 4:59 pm

Would this design be able to take off from a treadmill?

NameOmitted · Sun Jan 13, 2019 6:21 pm

If the strut is also an airfoil, any the angle it's mounted, wouldn't much of the lift generated actually be directed at an angle that pulls inboard rather than up?

I'm not doubting, I don't know enough to do so, and I know most aircraft have an angle to the wings, I'm just curious. Thank you.

JayinKitsap · Sun Jan 13, 2019 7:26 pm

kitplane01 wrote:
Technical questions ...

1) The struts look airfoil shaped. On smaller aircraft one uses the smallest physically reasonable strut, because an airfoil shaped strut produces an excess of drag compared to lift. Are the struts large because they are so worried about flutter on the wing, and so want to attach to both the fore and aft portions of the wing? Or are aerodynamics such that the lift is worth the drag? Or something else?

2) Will the wing have flaps and slats? Will they be as complex as current airliners? Almost all airliners do, but the span loading of this airplane is quite different. Avoiding slats/flaps would be an advantage.

3) What altitude will this fly at? The paper does not say, nor does the SUGAR documents. But it's unlikely to be optimized for the same conditions as a 737 since it's so different than a 737.

It is clear in the linked article and other reports that the struts are providing lift. Looking at the pictures the strut has about the same L/D as the main wing. It looks like the main wing is more swept than the strut, did they locate it so the engine exhaust is speeding up the above strut flow.

As to altitude it indicated it can fly higher and more economical that current aircraft.

Possibly a new version of the E2 is coming with this. As long as the folding wings allow the plane to fit at a NB gate it would be easy to integrate.

1989worstyear · Sun Jan 13, 2019 10:27 pm

seabosdca wrote:
kitplane01 wrote:
I don't know why you think the A320 wing is the best. I would imagine the A220 and the 787 were both better. The A320 wing is very span constricted.

That poster's gimmick is to claim that nothing has improved in commercial aviation, or at least narrowbodies, since the day the A320 entered service.

In the real world, it's not even true in the A320's market segment. The 737NG wing was all-new and developed a decade after that of the A320, and it's one of the two reasons (the other being weight) why the 737 stayed competitive despite its other disadvantages.

Nothing changed during that decade though, and I'm by far not the only one who thinks the A320 wing is this one of the best available. Please see the A320 rewing thread from a few months ago.

EBJ68 · Sun Jan 13, 2019 11:20 pm

I don't see what Wall Street would have to do with it. In its time, Boeing's concepts for an SST would have been seen as radical, in the context of then current airliners, but Boeing went ahead with the intent to develop, test and produce.

kitplane01 · Mon Jan 14, 2019 2:05 am

aw70 wrote:
What surprises me most about the braced NASA / Boeing design is the fact that they deem it worthwhile to attach struts to the thing. Sure, these allow them to make the main wing thinner and lighter. But the attachment point of the struts to the main wing also creates a really nasty interference point: and optimising the shape of that spot is only going to be really possible for a particular speed and AOA. Seems to be worth it, apparently - but the rest of the wing must be really great, to make this pay off.

It's about flutter!

It's a very high aspect ratio wing, moving very fast. The struts greatly reduce the propensity for flutter. Normal wings don't live with such a high aspect ration and high speed. They also help with strength, but the main point is flutter. That makes them very different than what you see on a C-172 (where the point is strength).

kitplane01 · Mon Jan 14, 2019 2:06 am

JayinKitsap wrote:
kitplane01 wrote:
Technical questions ...

1) The struts look airfoil shaped. On smaller aircraft one uses the smallest physically reasonable strut, because an airfoil shaped strut produces an excess of drag compared to lift. Are the struts large because they are so worried about flutter on the wing, and so want to attach to both the fore and aft portions of the wing? Or are aerodynamics such that the lift is worth the drag? Or something else?

2) Will the wing have flaps and slats? Will they be as complex as current airliners? Almost all airliners do, but the span loading of this airplane is quite different. Avoiding slats/flaps would be an advantage.

3) What altitude will this fly at? The paper does not say, nor does the SUGAR documents. But it's unlikely to be optimized for the same conditions as a 737 since it's so different than a 737.

It is clear in the linked article and other reports that the struts are providing lift. Looking at the pictures the strut has about the same L/D as the main wing. It looks like the main wing is more swept than the strut, did they locate it so the engine exhaust is speeding up the above strut flow.

As to altitude it indicated it can fly higher and more economical that current aircraft.

Possibly a new version of the E2 is coming with this. As long as the folding wings allow the plane to fit at a NB gate it would be easy to integrate.

Can you point to something I missed? I didn't see that explicitly, and my eyes cannot detect L/D ration from a picture.

kitplane01 · Mon Jan 14, 2019 2:12 am

1989worstyear wrote:
seabosdca wrote:
kitplane01 wrote:
I don't know why you think the A320 wing is the best. I would imagine the A220 and the 787 were both better. The A320 wing is very span constricted.

That poster's gimmick is to claim that nothing has improved in commercial aviation, or at least narrowbodies, since the day the A320 entered service.

In the real world, it's not even true in the A320's market segment. The 737NG wing was all-new and developed a decade after that of the A320, and it's one of the two reasons (the other being weight) why the 737 stayed competitive despite its other disadvantages.

Nothing changed during that decade though, and I'm by far not the only one who thinks the A320 wing is this one of the best available. Please see the A320 rewing thread from a few months ago.

Two things have changed

1) Carbon fibre allows for greater aspect ratios without great weight.

2) Aspect ratios have gone up.
A320 = 9.5 A220 = 10.5 787 = 11

Note that the A320 wing is span limited to fit into the needed gates. A modern wing would have more span.

parapente · Mon Jan 14, 2019 1:48 pm

https://www.flightglobal.com/news/artic ... et-454898/

Flight's take on the announcement.Well written as usual.
I note that NASA has also applied their aft boundary layer ingestion electric fan to this trussed wing concept as well -looking at some images on the web.

WayexTDI · Mon Jan 14, 2019 2:35 pm

NameOmitted wrote:
If the strut is also an airfoil, any the angle it's mounted, wouldn't much of the lift generated actually be directed at an angle that pulls inboard rather than up?

I'm not doubting, I don't know enough to do so, and I know most aircraft have an angle to the wings, I'm just curious. Thank you.

You are correct, the strut would generate lift that's angled towards the fuselage.

However, as both left and right sides have a lift-generating strut, the combined lift from both struts would end up being straight up; the horizontal components would cancel each other.

Remember, the wings on most aircraft are not perfectly angled flat.

CowAnon · Mon Jan 14, 2019 8:46 pm

kitplane01 wrote:
Note that the A320 wing is span limited to fit into the needed gates. A modern wing would have more span.

Sure, but with Boeing being comfortable reducing on-ground wingspan by about 1/3 through folding wings, maybe the OEMs would be tempted to apply folding wingtips to their existing wings without increasing wingspan? Then the A320 and B737 could fit in 24-meter-wide Code B airport gates, which would allow terminals to increase the number of gates by almost 50% without having to increase their footprints.

CowAnon · Tue Jan 15, 2019 6:35 am

parapente wrote:
The big bit missing imho is what a conventional 'new' NSA could do ( be)?
Ie how far could an conventional low wing carbon fibre folding wing be stretched ( aspect ratio) without needing to go 'high wing and struts '.What would the performance differential be I wonder?

Aviation Week discussed this in reporting on a previous iteration of the aircraft in 2014.

https://aviationweek.com/blog/will-boeing-embrace-braced-wings wrote:
Most jetliner wings have an aspect ratio around 9. Thanks to their stiff carbon-fiber wings, the Boeing 787 and Bombardier CSeries push this to 11. With active flutter suppression and gust-load allevation to control the structural flexibility, you might get to 15 with a conventional "cantilevered" wing supported only at its roots.

https://aviationweek.com/awin/nasa-boeing-test-low-drag-truss-braced-wing-concept wrote:
The optimized truss-braced wing (TBW) has a span of more than 173 ft., compared with 113 ft. for the 737, and an aspect ratio of around 19.

parapente · Tue Jan 15, 2019 7:05 am

Thx cowanon.Quite a big difference 25% give or take.Whilst one cannot be certain there appears to me to be an additional structural problem for any conventional NB wing.It would of course have to be hinged if it is to go an inch further than present 737 widths.The 'strut/braced' concept has the additional strength required built in.For a 'conventional' wing adding this additional structure that far out would be mighty difficult.
Clearly a start has been made with the 777x but that is tiny ( and in a huge wing) compared to the aspect ratio's being discussed here.
Anyway I guess Boeing have in a sense answered the question by choosing the route they have.If conventional was 'as good/better' then that's what they would have definitely done.
Shame it's all a decade away.But having said that it might buy time to look further into the hybrid aspects and boundary layer ingestion.

seahawk · Tue Jan 15, 2019 7:55 am

Folding 1/3 of such a high aspect ratio wing will be interesting. It could require something like the C-2/E-2 mechanism.

SheikhDjibouti · Tue Jan 15, 2019 2:34 pm

seahawk wrote:
Folding 1/3 of such a high aspect ratio wing will be interesting. It could require something like the C-2/E-2 mechanism.

bigjku · Tue Jan 15, 2019 3:44 pm

seahawk wrote:
Folding 1/3 of such a high aspect ratio wing will be interesting. It could require something like the C-2/E-2 mechanism.

It would really come down to what kind of control surfaces you need way out there. With FBW controls you can possibly get by without putting control surfaces on the folded portion which makes it very much simpler. Electric actuators also simplifies things if you do have to fold it.

neutrino · Tue Jan 15, 2019 4:00 pm

SheikhDjibouti wrote:
seahawk wrote:
Folding 1/3 of such a high aspect ratio wing will be interesting. It could require something like the C-2/E-2 mechanism.

Should be simpler than the Hawkeye's twist-fold, as the TTBW aircraft has less restriction on height than that of carrier-borne planes.
Can something like the following two work? Or will the up-folded section still be too tall for airports even if canted inwards like in the first pic?
In that case, how about a double hinge ie mid and outer hinged sections, first upwards and then down?

vahancrazy · Tue Jan 15, 2019 4:10 pm

neutrino wrote:
Should be simpler than the Hawkeye's twist-fold, as the TTBW aircraft has less restriction on height than that of carrier-borne planes.
Can something like the following two work? Or will the up-folded section still be too tall for airports even if canted inwards like in the first pic?
In that case, how about a double hinge ie mid and outer hinged sections, first upwards and then down?

I struggle to imagine any airport where the foldedwing might cause problems

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