We know it's coming, just a matter of when, so between the Trent Ultrafan's big efficiency improvements (7-10% over the XWB seems likely) and Airbus' improvements to the frame (wing twist, new laminar coatings/designs from Project BLADE, folding wingtips, etc.), what do we think the A350 NEO specs will be?

With a 10% range improvement, the A350 900 and 1000 base models have the same and higher range than the 777-8. Not quite the 18,000km of the -900ULR, but that's before any pax or cargo restrictions. The only routes much longer than 17,200km are Aukland to London, Singapore to Chicago, and Perth to NYC, and of those, only Aukland-London has been seriously floated.

So, would this not, essentially, remove the need to have an A350 NEO ULR?

And as a side question, with the delayed EIS for the 777-8, should Boeing even bother with it at this point if they don't win the Project Sunrise bid?

patrickjp93 wrote:

We know it's coming, just a matter of when, so between the Trent Ultrafan's big efficiency improvements (7-10% over the XWB seems likely) and Airbus' improvements to the frame (wing twist, new laminar coatings/designs from Project BLADE, folding wingtips, etc.), what do we think the A350 NEO specs will be?

With a 10% range improvement, the A350 900 and 1000 base models have the same and higher range than the 777-8. Not quite the 18,000km of the -900ULR, but that's before any pax or cargo restrictions. The only routes much longer than 17,200km are Aukland to London, Singapore to Chicago, and Perth to NYC, and of those, only Aukland-London has been seriously floated.

So, would this not, essentially, remove the need to have an A350 NEO ULR?

And as a side question, with the delayed EIS for the 777-8, should Boeing even bother with it at this point if they don't win the Project Sunrise bid?

First, I think it's a question of time to market. QF has put its flag in the ground on PER-LHR and wants to be the pioneer on SYD-LHR. They do not want to wait till A350neo with UltraFan is ready for market. They feel they will make money on SYD-LHR and they don't want anyone else to take that market first.

Second, I would not pencil in BLADE improvements for A350neo.

As https://en.wikipedia.org/wiki/Breakthro ... _in_Europe says:

Its wing sweep is around 20° for a Mach 0.75 cruise instead of 30° for Mach 0.82-0.84, laminar flow is expected along 50% of chord length instead of just aft of the leading edge, halving the wing friction drag, reducing the overall aircraft drag by 8% and saving up to 5% in fuel on an 800nm (1,480km) sector.[1]
...
The aerodynamic benefits could be sustained at Mach 0.78 up from M0.75 and next-generation single-aisles could use from the late 2020s.

The A350's wing has a 31.9° sweep angle for a Mach 0.85 cruise speed ( ref: https://en.wikipedia.org/wiki/Airbus_A350_XWB ).

The BLADE results are very good, but really only meaningful for a single aisle where cruise speed is not commercially significant.

Also BLADE only works when one holds extremely high manufacturing tolerances, which adds a lot of cost to build and maintain so you'd only use it when it paid for itself.

A350neo would need an all-new wing with redesign of the wingbox for different sweep angle and accept a slower cruise speed to benefit from BLADE.

I don't think this is the approach Airbus will take for A350neo.

And I think QF is happy to take the bird in hand rather than the two in the bush.

Revelation wrote:

First, I think it's a question of time to market. QF has put its flag in the ground on PER-LHR and wants to be the pioneer on SYD-LHR. They do not want to wait till A350neo with UltraFan is ready for market.

Second, I would not pencil in BLADE improvements. As https://en.wikipedia.org/wiki/Breakthro ... _in_Europe says:

Its wing sweep is around 20° for a Mach 0.75 cruise instead of 30° for Mach 0.82-0.84, laminar flow is expected along 50% of chord length instead of just aft of the leading edge, halving the wing friction drag, reducing the overall aircraft drag by 8% and saving up to 5% in fuel on an 800nm (1,480km) sector.[1]
...
The aerodynamic benefits could be sustained at Mach 0.78 up from M0.75 and next-generation single-aisles could use from the late 2020s.

The A350's wing has a 31.9° sweep angle for a Mach 0.85 cruise speed ( ref: https://en.wikipedia.org/wiki/Airbus_A350_XWB ).

The BLADE results are very good, but really only meaningful for a single aisle where cruise speed is not commercially significant.

Also BLADE only works when one holds extremely high manufacturing tolerances, which adds a lot of cost to build and maintain so you'd only use it when it paid for itself.

A350neo would need an all-new wing with redesign of the wingbox for different sweep angle and accept a slower cruise speed to benefit from BLADE.

I don't think this is the approach Airbus will take for A350neo.

And I think QF is happy to take the bird in hand rather than the two in the bush.

Thanks for the info. That said, there'll be derivative IP coming out of BLADE. We know mach 0.78 is much more efficient than 0.85, just as mach 5+ is more efficient than 4.9 and down for supersonic flight. But no one would want to SLOW DOWN a 20+ hour flight to a 22 hour flight.

patrickjp93 wrote:

Thanks for the info. That said, there'll be derivative IP coming out of BLADE. We know mach 0.78 is much more efficient than 0.85, just as mach 5+ is more efficient than 4.9 and down for supersonic flight. But no one would want to SLOW DOWN a 20+ hour flight to a 22 hour flight.

I agree. We can have gotten many generations of improvements from engines but researchers say that we're hitting fundamental limits and we will need to look elsewhere for gains, with laminar flow being one of the obvious areas to look at. The problem is even when we can make it work we sacrifice speed and increase cost to build and maintain, yet various clean air initiatives will make it so it has to be put into production. I think the quoted late 2020s narrow body airliner is a likely target.

Revelation wrote:

I agree. We can have gotten many generations of improvements from engines but researchers say that we're hitting fundamental limits and we will need to look elsewhere for gains, with laminar flow being one of the obvious areas to look at. The problem is even when we can make it work we sacrifice speed and increase cost to build and maintain, yet various clean air initiatives will make it so it has to be put into production. I think the quoted late 2020s narrow body airliner is a likely target.

I think geared fans and greater use of composite materials in engines will buy us another 30-50 years of steady improvements. Again, there's just no practical use for a plane with 19,800km of range, which would be an exact 10% improvement for the A350-900ULR, so the knock-on effects of having the next-generation engines is we can start reducing fuel used to achieve the target ranges we had before, and less fuel needed means narrower wings, which improves performance, and so on.

The 737 MAX in particular is a bit of a WTF aircraft at this point. The M8 and M7 can both do Transatlantic service with 120-160 souls on board, but that's a range the 737 was never designed to handle (logistics of full-service galleys in particular). It was meant to be a regional flier in the air no longer than 5 hours (essentially, able to cross the U.S., but not much more than that). To improve in its original regional mission and better compete with the A220 and A320, the Max needs to trim up its wings and cut some fuel weight.

If 10% improvement was all we got out of the A350 NEO, the ULR variant would only be justified for 1-2 customers: Air New Zealand for AKL-LHR, and MAAAAYBE Qantas for PER-JFK if Perth ever grew important enough. But to get the most utility out of the design, you would spec it for LESS fuel than the current capacity, not the same. Probably targeting 19,100km range. This gives you more cargo and pax load too if you design for the same MTOW.

Revelation wrote:

Also BLADE only works when one holds extremely high manufacturing tolerances, which adds a lot of cost to build and maintain so you'd only use it when it paid for itself.

And BLADE stops working when a bug gets smushed on the leading edge, at least in that small section. That's something that they're going to have to figure out before EIS, because bugs and dirt are part of real-world operations.

patrickjp93 wrote:

Again, there's just no practical use for a plane with 19,800km of range, which would be an exact 10% improvement for the A350-900ULR,

There are a few uses, but not many. Very few passengers will ever take a flight longer than 12 hours. I've traveled around the world and the longest flight I've ever taken was SFO-SYD. 18+ hour ULH flights are a really niche product that the average passenger will never want to take. Like you said, the big advantage will be reduced fuel burn.

DocLightning wrote:

Revelation wrote:

Also BLADE only works when one holds extremely high manufacturing tolerances, which adds a lot of cost to build and maintain so you'd only use it when it paid for itself.

And BLADE stops working when a bug gets smushed on the leading edge, at least in that small section. That's something that they're going to have to figure out before EIS, because bugs and dirt are part of real-world operations.

Results from BLADE seem to show that requirements can be slightly relaxed
and resilience to disturbances is better than expected.
( hmm, what did they expect actually? )

DocLightning wrote:

And BLADE stops working when a bug gets smushed on the leading edge, at least in that small section. That's something that they're going to have to figure out before EIS, because bugs and dirt are part of real-world operations.
.

this is why Boeing tested on 757 Krueger slats to protect surfaces critical for laminar flow.
But.
this is about Boeing.
Airbus already awared about this issue while making BLADE testbed.
so they must be trying to manage somehow this issue.

Do you have any info about Aibus facing this issue, not about Boeing?



upd: i noticed Airbus have to test their own krueger flaps (why flaps instead of slats?) but cant find any more info about this.

kruger flaps, morphing flaps, morphing wing are "in sight" for BLADE (~2020)
meta link: https://www.google.com/search?q=AIRBUS+ ... s+morphing

WIederling wrote:

Results from BLADE seem to show that requirements can be slightly relaxed
and resilience to disturbances is better than expected.

source link:
https://www.ainonline.com/aviation-news ... pectations
( also touches on the future path to be taken )

http://www.aeromorning.com/en/asco-comp ... to-airbus/

Krueger flaps has been delivered in june 2017.
as i can see in news "test will continue until 2019" which i interpreting as "in 2018"

will be interesting to find more info about this

Armadillo1 wrote:

http://www.aeromorning.com/en/asco-completes-the-delivery-of-innovative-high-lift-devices-to-airbus/

Krueger flaps has been delivered in june 2017.
as i can see in news "test will continue until 2019" which i interpreting as "in 2018"

will be interesting to find more info about this

the "... Exceeds Expectations" article is from June 2018 so probably ahead of the flap campaign?

bit of ancillary info:
https://www.dlr.de/fa/Portaldata/17/Res ... chlipf.pdf

yep, we looking at the same google at the same time.

interesting those krueger flaps very different from 747 and really looks like shields

Armadillo1 wrote:

yep, we looking at the same google at the same time.

interesting those krueger flaps very different from 747 and really looks like shields

Basic concept of a Krüger Flap is folding a piece of the wing underside to extend beyond
the nose profile. ( where slats are a piece of the nose moved out/down and
drop nose devices rotate a piece of the nose profile down.)

Doesn't the 747 have a multipart articulated Krüger flap design?

WIederling wrote:

Armadillo1 wrote:

yep, we looking at the same google at the same time.

interesting those krueger flaps very different from 747 and really looks like shields

Basic concept of a Krüger Flap is folding a piece of the wing underside to extend beyond
the nose profile. ( where slats are a piece of the nose moved out/down and
drop nose devices rotate a piece of the nose profile down.)

Doesn't the 747 have a multipart articulated Krüger flap design?

yes , 727 has simple flat krueger flaps and 747 complex (and heavy)
https://ntrs.nasa.gov/archive/nasa/casi ... 052267.pdf


A300 has small krueger flaps too


but none of this can be moved upward like on this pics for BLADE, which used as bug shield for laminar wing.
And all used for small inner wing area, not for entire wing like that proposal.

i wonder how much disadvatage this added for design, compared to common high-lift system.

Well it is a Krueger articulated (sealed? no ) slat then?

though my understanding of Krueger would require it to simply hinge near the lower tip of the nose.
( what made the original design from Krüger very attractive.)
This flap here shows complex articulation .

Proper low disturbance sealing of the retracted flap can't be easy.

WIederling wrote:

Well it is a Krueger articulated (sealed? no ) slat then?

though my understanding of Krueger would require it to simply hinge near the lower tip of the nose.
( what made the original design from Krüger very attractive.)
This flap here shows complex articulation .

Proper low disturbance sealing of the retracted flap can't be easy.

english not my language so i have no idea why Krueger slats named flaps.
2002-year a-net topic declare "slats created slot and Krueger not" but i not believe this explanation.

original flat krueger on 727 simple, but not so efficient.
nowadays krueger (and tripple-slotted flaps) dropped for more light but not less efficient solutions. and for inner section now its a dropped nose only.

for laminar wing bug shield is important so they made it complex and place ahead of upper part of the wing. I wonder - this may be even less efficient than 747 krueger



also, if we talk about laminar flow for mach number increase - it need to be certified for laminar flow failure, emergensy descent in this case and reserve fuel in this case.

Armadillo1 wrote:

english not my language so i have no idea why Krueger slats named flaps.

WP:EN:
"Krüger flaps were invented by Werner Krüger in 1943 and evaluated in the wind tunnels in Göttingen, Germany."

patrickjp93 wrote:

So, would this not, essentially, remove the need to have an A350 NEO ULR?

The A350 family is already at the edge of the widebody sweet spot. The A330-300 and 777-300ER were the two big sellers that give an idea of the sweet spot. The A350 is on the upper edge of the sweet spot for size. The range of the A350 is pushing beyond the sweet spot and is close to the niche aircraft like the A340-500 and 777LR. Both of these did not sell.

Once the A350NEO comes it will have too much range and a lighter frame of similar cabin area can offer more efficiency. The 787-10 NEO will be the big seller in the future.

patrickjp93 wrote:

And as a side question, with the delayed EIS for the 777-8, should Boeing even bother with it at this point if they don't win the Project Sunrise bid?

Boeing definitely shouldn't bother with the 777-8 if it does not get selected for Project Sunrise.

I actually think the VLA market is shrinking faster than people think. The A380 retirement plans are faster than we would expect which shows the demand must extremely high for medium sized widebodies. Pushing investment into the 787 might prove the smart option and reap rewards in 10 years time. A 787-8ER and 787-8 freighter would be the safe option right now.

The second problem is the big winged 777X is built for long range cruise which makes it a poor freighter with next to no improvement over the current 777F. The argument that the 777-8 should be built so that it can become the future freighter if a poor argument.

Boeing got one thing right with the 787 it was sized perfectly for decades to come.

RJMAZ wrote:

patrickjp93 wrote:

So, would this not, essentially, remove the need to have an A350 NEO ULR?

The A350 family is already at the edge of the widebody sweet spot. The A330-300 and 777-300ER were the two big sellers that give an idea of the sweet spot. The A350 is on the upper edge of the sweet spot for size. The range of the A350 is pushing beyond the sweet spot and is close to the niche aircraft like the A340-500 and 777LR. Both of these did not sell.

The "sweet spot" is calculated based on a number of factors, mind you. Most would say the 10-hour range of the NMA by Boeing is the sweet spot, or essentially LA to Tokyo, but we of course have need of craft with 60+% more range than that. There will likely never be more than 50 craft from any single family needed for "Sunrise" and its equivalents like Auckland to London and Hong Kong to Miami. The craft will easily fly 20 years. Someone has to make them. As niche as the market is, small tweaks to existing frames to make it work make the overall economic outlook of the family much better.

Once the A350NEO comes it will have too much range and a lighter frame of similar cabin area can offer more efficiency. The 787-10 NEO will be the big seller in the future.

Don't know if I'd say that. It might play well with Qantas, Singapore, and Etihad, but with only 10% more range, it could just barely fly BNE-LAX, a significant up-gauge that would also improve LAX-JFK vs. the crippled 789 frames currently used for it. It wouldn't gain Singapore all that much in terms of routes it currently flies unless some could be optimally down-gauged.

patrickjp93 wrote:

And as a side question, with the delayed EIS for the 777-8, should Boeing even bother with it at this point if they don't win the Project Sunrise bid?

Boeing definitely shouldn't bother with the 777-8 if it does not get selected for Project Sunrise.

I actually think the VLA market is shrinking faster than people think. The A380 retirement plans are faster than we would expect which shows the demand must extremely high for medium sized widebodies. Pushing investment into the 787 might prove the smart option and reap rewards in 10 years time. A 787-8ER and 787-8 freighter would be the safe option right now.

The second problem is the big winged 777X is built for long range cruise which makes it a poor freighter with next to no improvement over the current 777F. The argument that the 777-8 should be built so that it can become the future freighter if a poor argument.

Boeing got one thing right with the 787 it was sized perfectly for decades to come.

Some freight routes are long enough to justify the 777X freighter, and it'll improve the economics vs the old 777F well enough that people will buy it. Think Sydney or Brisbane to Los Angeles. Freight in and out of Australia is ridiculously expensive, in part because there is no particularly efficient freighter flying it. Heck I still see MD-80s in use by UPS that specifically fly to Hong Kong to load up a big 777F to fly across the Pacific.

Or Singapore to northern Canada by way of a 777-8F or A350F before the load gets broken down and dispersed to shorter legs. Hub & Spoke is still the active model for freight for this very reason: efficiency. That said, in these new days of 1-2 day shipping requirements, you have to cut the time out somewhere.