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by Taxi645
Tue Mar 20, 2018 8:24 am
Forum: Technical/Operations
Topic: 2025ish A380-900NEO
Replies: 177
Views: 27359

Re: 2025ish A380-900NEO

Matt6461 wrote:
Taxi45 wrote:
The A380Mk2 vs. The CEO and the 777x:


We'd need, at least, OEW's and L/D's to evaluate your projections.


Still working on the house so time restricted (and knowledge and tools), but OEW would be ~262.4t.

Aero will take more time. Perhaps next week.

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by Taxi645
Mon Mar 19, 2018 2:49 pm
Forum: Technical/Operations
Topic: 2025ish A380-900NEO
Replies: 177
Views: 27359

Re: 2025ish A380-900NEO

The A380-850 https://s9.postimg.org/wdog0h7vz/A380-850_75m_2.jpg Nacelles: similar diameter; thrust reduction similar to bypass increase. Nacelles shortened for reduced surface area/drag. Engines are still lighter because of shorter nacelles and lighter core. Empennage size: -15% Wing area: -15% Ef...

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by Taxi645
Sun Feb 18, 2018 11:47 am
Forum: Technical/Operations
Topic: 2025ish A380-900NEO
Replies: 177
Views: 27359

Re: 2025ish A380-900NEO

[*]You ignore the empennage. Even the belated NEO proposals modified the empennage; this is lower-hanging fruit than MLG/cargo revisions. I only ignored it in my presentation not the calculation, because I wanted to focus on the implications of the update and open peoples eyes rather than filling t...

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by Taxi645
Fri Feb 16, 2018 10:23 pm
Forum: Technical/Operations
Topic: 2025ish A380-900NEO
Replies: 177
Views: 27359

Re: 2025ish A380-900NEO

I'll try to briefly explain a bit more why the A380Mk2 vs. 777x situation is quite different from the A380 vs. 773 situation and what the implications are. Leeham in 2014 published an interesting article on a A380NEO and how it related to the competition: https://leehamnews.com/2014/02/03/updating-t...

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by Taxi645
Thu Feb 01, 2018 10:37 pm
Forum: Technical/Operations
Topic: 2025ish A380-900NEO
Replies: 177
Views: 27359

Re: 2025ish A380-900NEO

I think you're strongly underestimating the weight saving potential of a 2nd gen. A380 optimized around it's capacity especially with GTF engines. I think you underestimate the cost of an optimized A380. A new carbon wing, centre wingbox, engines, landing gear, stretch and tail would easily cost tw...

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by Taxi645
Thu Feb 01, 2018 10:30 am
Forum: Civil Aviation
Topic: Airbus A330neo Production/Delivery Thread 2018
Replies: 441
Views: 134163

Re: Airbus A330neo Production/Delivery Thread 2018

olle wrote:
as I remember the A358 was going to perform better then the A333. I think in mid 2020s we will see a A358 with smaller wing replacing A339.


If so I suspect the wingspan to remain the same.

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by Taxi645
Thu Feb 01, 2018 10:15 am
Forum: Technical/Operations
Topic: 2025ish A380-900NEO
Replies: 177
Views: 27359

Re: 2025ish A380-900NEO

A new lighter carbon wing wouldn't rank high on the cost Vs benefit scale. The current wing we might say is 10% oversized in terms of weight, size and lift. However if a stretch comes it might be only 5% oversize and overweight. So we've halved the amount of improvement that a new carbon wing would...

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by Taxi645
Wed Jan 31, 2018 8:34 am
Forum: Technical/Operations
Topic: 2025ish A380-900NEO
Replies: 177
Views: 27359

Re: 2025ish A380-900NEO

No Airbus is doing this because it has bigger plans for the A380 in the future. Airbus problem is that the A380 as a design will turn "outdated". Things move on. In that respect Boeing has entangled Airbus quite successfully with their FUD campaign. Surely at some point the A380 concept w...

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by Taxi645
Tue Jan 30, 2018 10:08 am
Forum: Technical/Operations
Topic: 2025ish A380-900NEO
Replies: 177
Views: 27359

Re: 2025ish A380-900NEO

The issue isn't simply -900 vs. -850. It's -900NEO (no new wing) versus -850X (new wing), plus development cost/risk of each option. There is no reasonable doubt that an -850X would be a far better product than -900NEO, but it would it cost much more to develop. I'll make an argument for a new wing...

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by Taxi645
Tue Jan 30, 2018 9:16 am
Forum: Technical/Operations
Topic: Elleptical vs Bell spanload distribution on commercial airliners.
Replies: 5
Views: 1321

Re: Elleptical vs Bell spanload distribution on commercial airliners.

Bell curve seems to be most appropriate for flying wing designs. bell distribution makes the design steerable and _allows_ surface reductions ( no tail ). As long as you have a conventional plane ( wings, fuselage, h/v tailplanes ) design ... Why is that so? It seems the Bell curve has two distinct...

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by Taxi645
Mon Jan 29, 2018 11:32 am
Forum: Technical/Operations
Topic: 2025ish A380-900NEO
Replies: 177
Views: 27359

Re: 2025ish A380-900NEO

That depends rather highly on what you believe an A330 sucessor might be. If it's a widebody taking the 787 head-on in capability, it's engines will be way overbuilt and heavy for your A380X, 500t MTOW needs nowhere near 4x70klbf. If A intends to make the A330 sucessor a "MoM" product, th...

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by Taxi645
Mon Jan 29, 2018 9:54 am
Forum: Technical/Operations
Topic: Elleptical vs Bell spanload distribution on commercial airliners.
Replies: 5
Views: 1321

Re: Elleptical vs Bell spanload distribution on commercial airliners.

Bell curve seems to be most appropriate for flying wing designs. bell distribution makes the design steerable and _allows_ surface reductions ( no tail ). As long as you have a conventional plane ( wings, fuselage, h/v tailplanes ) design ... Why is that so? It seems the Bell curve has two distinct...

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by Taxi645
Mon Jan 29, 2018 9:37 am
Forum: Technical/Operations
Topic: 2025ish A380-900NEO
Replies: 177
Views: 27359

Re: 2025ish A380-900NEO

Both the projected sales and development costs seem rather optimistic IMO. The 777X involved far less new stuff (wing + engine) and its rumored to be a 6-7B program, it's hard to imagine a new MLG, wingbox, and empennage not costing at least 5B extra on top of that. As argued a 850 could share engi...

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by Taxi645
Sun Jan 28, 2018 1:46 pm
Forum: Technical/Operations
Topic: 2025ish A380-900NEO
Replies: 177
Views: 27359

Re: 2025ish A380-900NEO

Say at 505T MTOW the six-wheel bogey could be replaced by an 4-wheel one and could be stored vertically. Say this would save 1.2 container length. To harvest the container length you need to completely redesign the MLG bay. I proposed this in past A380X sketches and it would be (operationally) bene...

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by Taxi645
Fri Jan 26, 2018 9:52 pm
Forum: Technical/Operations
Topic: Elleptical vs Bell spanload distribution on commercial airliners.
Replies: 5
Views: 1321

Elleptical vs Bell spanload distribution on commercial airliners.

Elleptical vs Bell spanload distribution on commercial airliners. Bell shaped spanloading explained here: https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20160003578.pdf or here: https://www.youtube.com/watch?v=Hr0I6wBFGpY We're seeing quite aggressive expansion of AR ratio late accompanied by...

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by Taxi645
Fri Jan 26, 2018 8:05 pm
Forum: Technical/Operations
Topic: 2025ish A380-900NEO
Replies: 177
Views: 27359

Re: 2025ish A380-900NEO

Say at 505T MTOW the six-wheel bogey could be replaced by an 4-wheel one and could be stored vertically. Say this would save 1.2 container length. Now say they could get the weight down to 490T by: much smaller 80m CFRP wing fuel load reduction from GTF engine, lower MTOW, massive induced drag reduc...

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by Taxi645
Mon Jan 08, 2018 7:26 pm
Forum: Civil Aviation
Topic: AIRBUS 2020-2030 development projects A360, A370 opportunities.
Replies: 289
Views: 62133

Re: AIRBUS 2020-2030 development projects A360, A370 opportunities.

I'm very curious how Airbus is going to translate the SFC gains of an ultrafan like engine into the A350 design, knowing that it already has plenty of range...

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by Taxi645
Sat Jan 06, 2018 1:06 am
Forum: Civil Aviation
Topic: Airbus CEO Tom Enders Is Aviation Week 2017 Person Of The Year
Replies: 10
Views: 1391

Re: Airbus CEO Tom Enders Is Aviation Week 2017 Person Of The Year

I'm surprised some people are able to come to such definitive conclusions as an outsider while in most companies sometimes critical information doesn't even survive the transistion to the next management layer...

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by Taxi645
Tue Nov 28, 2017 10:42 am
Forum: Technical/Operations
Topic: Revising the A380 NEO MLG
Replies: 11
Views: 14331

Re: Revising the A380 NEO MLG

Perhaps someone more technically inclined would be so kind to step in and expand a bit on the feasibility of the A380 front bogie being stored in the wing? The A380 wing skin is an Al multi layer "composite" load bearing item. If you start to break it for gear doors ... ... Load bearing s...

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by Taxi645
Tue Nov 28, 2017 9:35 am
Forum: Technical/Operations
Topic: Revising the A380 NEO MLG
Replies: 11
Views: 14331

Re: Revising the A380 NEO MLG

Agreed. But the A359 already uses a 4-wheel bogie. Most likely more advanced (?lighter?) than the 4-wheel bogie currently used on the A380. So no need to redesign anything, other than fitting. Whatever off-the-shelf parts (or close to) from the A350 that it (A380) can use, the better. Airbus has to...

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by Taxi645
Tue Nov 28, 2017 9:13 am
Forum: Civil Aviation
Topic: Airbus Working With Emirates on New Order for Flagship A380
Replies: 948
Views: 709259

Re: Airbus Working With Emirates on New Order for Flagship A380

I would be quite surprised if Emirates gets the kind of commitment from Airbus they say they want. For Airbus that would mean committing to the A380NEO 2-3 years earlier than they otherwise would have to. Furthermore the engine for the A380NEO would most probably need to be tide to another program t...

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by Taxi645
Mon Nov 27, 2017 7:50 pm
Forum: Technical/Operations
Topic: Revising the A380 NEO MLG
Replies: 11
Views: 14331

Re: Revising the A380 NEO MLG

The HAW-Hamburg link is munged: http://www.fzt.haw-hamburg.de/pers/Scholz/dglr/hh/text_2008_06_05_LandingGear.pdf some historic overview: http://www.fzt.haw-hamburg.de/pers/Scholz/dglr/hh/text_2002_04_11_Fahrwerk.pdf Thanks WIederling, very informative. I'm thinking the maximum gain in the number o...

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by Taxi645
Sun Nov 26, 2017 11:40 am
Forum: Technical/Operations
Topic: Revising the A380 NEO MLG
Replies: 11
Views: 14331

Re: Revising the A380 NEO MLG

I'll add a video and a PDF to make more clear what the current configuration is. Hopefully it is more obvious then how a vertically stored 4-wheel boogie (instead of the 6 wheels boogie now) would save a lot of space (if it fit's vertically): https://www.youtube.com/watch?v=3lz96Xi07js http://www.fz...

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by Taxi645
Sun Nov 26, 2017 11:12 am
Forum: Civil Aviation
Topic: Airbus weighs response if Boeing launches new mid-market model
Replies: 1000
Views: 211367

Re: Airbus weighs response if Boeing launches new mid-market model

If Boeing launch the 797 next year - obviously with a competition for a new 50klbs thrust geared fan then any response must follow that timing plan.So circa 10 years.More if Airbus waits a little to gauge response. Using some variant of the 330 fuse must be seen in this light.Is it still going to b...

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by Taxi645
Sat Nov 25, 2017 6:36 pm
Forum: Technical/Operations
Topic: Revising the A380 NEO MLG
Replies: 11
Views: 14331

Revising the A380 NEO MLG

In this very informative thread; http://www.airliners.net/forum/viewtopic.php?f=5&t=771991&p=11193763&hilit=a380+wing+high+efficiency#p11137069 Ferpe and Klaus pointed out that the A380 MLG design takes up a lot of potential cargo volume, also because the 6-wheel bogie can't be stored up...

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by Taxi645
Fri Nov 24, 2017 8:33 am
Forum: Technical/Operations
Topic: Expert help: Wing aspect ratio/ spanlading vs induced drag
Replies: 26
Views: 20952

Re: Expert help: Wing aspect ratio/ spanlading vs induced drag

Matt6461 wrote:
Well that changes everything lol.


Good that we've got that straightened out! :thumbsup:

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by Taxi645
Thu Nov 23, 2017 8:37 am
Forum: Technical/Operations
Topic: Expert help: Wing aspect ratio/ spanlading vs induced drag
Replies: 26
Views: 20952

Re: Expert help: Wing aspect ratio/ spanlading vs induced drag

I am curious how wingtip devices effect this. Are the modeled as an increase in effective wingspan, or something else? I'm obviously a non expert on this, but I have read the wing tips height is counted for as extension of effective wingspan with a factor of 0.45. Wingtip height below wing (scimite...

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by Taxi645
Thu Nov 23, 2017 8:31 am
Forum: Technical/Operations
Topic: Expert help: Wing aspect ratio/ spanlading vs induced drag
Replies: 26
Views: 20952

Re: Expert help: Wing aspect ratio/ spanlading vs induced drag

Thank you for joining in Matt. I was hoping you would and part of the reason to open the thread was to have a place to discuss this. [*]2. Reducing weight of a plane with given wing dimensions means the plane flies higher in lower-density air (unless engines are climb-limited or ceiling is reached)....

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by Taxi645
Wed Nov 22, 2017 7:49 pm
Forum: Technical/Operations
Topic: Expert help: Wing aspect ratio/ spanlading vs induced drag
Replies: 26
Views: 20952

Re: Expert help: Wing aspect ratio/ spanlading vs induced drag

Thank you very much heavymetal. Very helpfull.

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by Taxi645
Tue Nov 21, 2017 11:14 pm
Forum: Civil Aviation
Topic: Airbus Working With Emirates on New Order for Flagship A380
Replies: 948
Views: 709259

Re: Airbus Working With Emirates on New Order for Flagship A380

If the A380NEO will not be stretched and will use a GTF engine together with a rigorous weight saving program centred around the 800, I expect the thrust requirements for the NEO to be significantly lower than for the CEO. That's where it's getting interesting. The future of the A380 is maybe withi...

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by Taxi645
Tue Nov 21, 2017 7:32 pm
Forum: Civil Aviation
Topic: Airbus Working With Emirates on New Order for Flagship A380
Replies: 948
Views: 709259

Re: Airbus Working With Emirates on New Order for Flagship A380

If the A380NEO will not be stretched and will use a GTF engine together with a rigorous weight saving program centred around the 800, I expect the thrust requirements for the NEO to be significantly lower than for the CEO. Quite close in fact to the requirement for an equally much lower weight succe...

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by Taxi645
Tue Nov 21, 2017 7:26 pm
Forum: Technical/Operations
Topic: Expert help: Wing aspect ratio/ spanlading vs induced drag
Replies: 26
Views: 20952

Re: Expert help: Wing aspect ratio/ spanlading vs induced drag

Thank you. I'm asking because we were having a discussion whether or not weight (as in design weight) could have an influence on the induced drag coefficient or not. Weight will affect induced drag, since weight affects the amount of lift required. I would argue, for instance in the case of the A38...

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by Taxi645
Tue Nov 21, 2017 10:44 am
Forum: Civil Aviation
Topic: Airbus Working With Emirates on New Order for Flagship A380
Replies: 948
Views: 709259

Re: Airbus Working With Emirates on New Order for Flagship A380

https://www.bloomberg.com/news/articles/2017-11-16/airbus-a380-deal-requires-pledge-to-build-jet-for-further-decade Airbus is caught between its desire to extend the life of the A380, in service for only a decade, and a reluctance to give a long-term commitment to a plane that has long been struggli...

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by Taxi645
Tue Nov 21, 2017 10:08 am
Forum: Technical/Operations
Topic: Expert help: Wing aspect ratio/ spanlading vs induced drag
Replies: 26
Views: 20952

Re: Expert help: Wing aspect ratio/ spanlading vs induced drag

A drag polar is the sum of profile drag and induced drag. Simply put, induced drag coefficient is the lift coefficient squared divided by the product of pi, aspect ratio and e. E is the span efficiency factor. Thank you. I'm asking because we were having a discussion whether or not weight (as in de...

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by Taxi645
Tue Nov 21, 2017 9:29 am
Forum: Civil Aviation
Topic: Airbus Working With Emirates on New Order for Flagship A380
Replies: 948
Views: 709259

Re: Airbus Working With Emirates on New Order for Flagship A380

That was then. Now there won't be a stretch without new engines in my view. Why though? They were good enough for the -900 and F. I do think it's pretty clear there is problem regarding the engines that had a big part to play with the delay in getting the signatures. I'm not sure going back to the ...

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by Taxi645
Mon Nov 20, 2017 8:56 pm
Forum: Technical/Operations
Topic: Expert help: Wing aspect ratio/ spanlading vs induced drag
Replies: 26
Views: 20952

Expert help: Wing aspect ratio/ spanlading vs induced drag

In several threads, including A380(NEO) threads, there have been discussions regarding the relation between wing aspect ratio and span loading (for a given weight, span and wing loading these are proportionate) on the one hand and induced drag on the other hand. Conflicting information can be found ...

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by Taxi645
Mon Nov 20, 2017 7:25 pm
Forum: Civil Aviation
Topic: Airbus Working With Emirates on New Order for Flagship A380
Replies: 948
Views: 709259

Re: Airbus Working With Emirates on New Order for Flagship A380

At the Paris Airshow in 2015, Airbus considered a "moderate" stretch that would have added approximately 50 seats. http://aviationweek.com/paris-air-show-2015/airbus-talking-airlines-about-slight-stretch-a380 https://www.flightglobal.com/news/articles/paris-airbus-in-early-talks-over-mode...

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by Taxi645
Mon Nov 20, 2017 12:38 pm
Forum: Civil Aviation
Topic: Airbus Working With Emirates on New Order for Flagship A380
Replies: 948
Views: 709259

Re: Airbus Working With Emirates on New Order for Flagship A380

Seems there is just a lot of hand wringing here about a debate over the basic problem of who is going to pay the bill for an aircraft that can’t sell. RR saying no more seems to be a big part of the issue. EK then basically put the onus on Airbus to step up and pay for improvements. They aren’t say...

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by Taxi645
Mon Nov 20, 2017 11:40 am
Forum: Civil Aviation
Topic: Airbus Working With Emirates on New Order for Flagship A380
Replies: 948
Views: 709259

Re: Airbus Working With Emirates on New Order for Flagship A380

It's overweight as it is stressed to take the extra loading from the -900 & -800F. Yes, that's what I think as well. It's overbuilt for strength and possibly fuel volume, but not wing loading in my view. Taking your number of 556 (I actually calc 531 kg/m2 @ 449.4 tonnes - MTOW - 1/2fuel capaci...

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by Taxi645
Mon Nov 20, 2017 11:24 am
Forum: Civil Aviation
Topic: Airbus Working With Emirates on New Order for Flagship A380
Replies: 948
Views: 709259

Re: Airbus Working With Emirates on New Order for Flagship A380

I dont think that a new wing is realistic. The cost would outweigh any fuel efficiency benefit given the small number of airframes to amortise it with. I don't necessarily think it would be that small a number. I wouldn't compare it to the market success of the CEO, so I suspect a properly executed...

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by Taxi645
Mon Nov 20, 2017 11:14 am
Forum: Civil Aviation
Topic: Airbus Working With Emirates on New Order for Flagship A380
Replies: 948
Views: 709259

Re: Airbus Working With Emirates on New Order for Flagship A380

It seems the whole wingloading/AR induced drag thing got deleted. Well that's allows us to stay on topic. Hope if it's okay I repost my reply to Amiga (please let me know if not). The A380 should have a lot of efficiency of scale, however due to it's weight and 80m span limit it has a span-loading i...

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by Taxi645
Mon Nov 20, 2017 9:01 am
Forum: Civil Aviation
Topic: Airbus Working With Emirates on New Order for Flagship A380
Replies: 948
Views: 709259

Re: Airbus Working With Emirates on New Order for Flagship A380

The circumstances will very much have changed as, unlike 2015, for EIS 2025-2028 there will be engines available that help to remove the 10% drag penalty the current A380 flies around with. By that time guarantees won't be required any more, cause finally then Airbus will have a competitive plain w...

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by Taxi645
Sun Nov 19, 2017 2:19 pm
Forum: Civil Aviation
Topic: Airbus Working With Emirates on New Order for Flagship A380
Replies: 948
Views: 709259

Re: Airbus Working With Emirates on New Order for Flagship A380

Personally I think that possibility was fully fleshed out during the 2014-5 NEO discussions and both sides emphasized that doing an A380neo without guarantees from customers other than EK was a non-starter. Since Airbus is now losing money on each A380 it produces I doubt that the circumstances hav...

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by Taxi645
Sun Nov 19, 2017 9:38 am
Forum: Civil Aviation
Topic: Airbus Working With Emirates on New Order for Flagship A380
Replies: 948
Views: 709259

Re: Airbus Working With Emirates on New Order for Flagship A380

But since we're blowing out of proportion, Airbus could offer a redesigned wing with other optimizations and the T7000 / GEnx until the end of next decade (new gen NEO), and ask EK for a 30 year commitment. :lol: Well, to stick it back into proportion - the two parties could widen the discussion to...

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by Taxi645
Sat Nov 18, 2017 8:38 am
Forum: Civil Aviation
Topic: Airbus Working With Emirates on New Order for Flagship A380
Replies: 948
Views: 709259

Re: Airbus Working With Emirates on New Order for Flagship A380

I think EK should realize that this moment they are not getting a guarantee from Airbus over the period they say they want. They will get the.planes cheap along with other favourable conditions and that's it. It's too early for Airbus to commit to an A380neo. The A380NEO is a high risk decision. The...

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by Taxi645
Wed Nov 15, 2017 8:37 am
Forum: Civil Aviation
Topic: Indigo Partners to order 430 A320s at Dubai
Replies: 124
Views: 31071

Re: Indigo Partners to order 430 A320s at Dubai

A noticeable absence of the A319 and C-series. In regards to the A319 that might indicate that: 1 Indeed Airbus is serious in dropping the A319 in favour of the C-series 2 Or there was no interest In regards to the C-series: 1 Perhaps still too soon after the Airbus/Bombardier deal with perhaps more...

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by Taxi645
Mon Nov 13, 2017 2:20 pm
Forum: Civil Aviation
Topic: Airbus Working With Emirates on New Order for Flagship A380
Replies: 948
Views: 709259

Re: Airbus Working With Emirates on New Order for Flagship A380

Like I said a few months ago, it's part of negotiations. Because they want to seal the deal now at the airshow everything is in the pressure cooker and more under the magnifying glass right now: http://www.airliners.net/forum/viewtopic.php?f=3&t=1357419&start=700#p19623921 It's not that comp...

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by Taxi645
Mon Nov 13, 2017 10:53 am
Forum: Civil Aviation
Topic: Airbus Working With Emirates on New Order for Flagship A380
Replies: 948
Views: 709259

Re: Airbus Working With Emirates on New Order for Flagship A380

Latest update from the air show: Dubai wants a guarantee that Airbus will keep production of the A380 superjumbo open for at least 10 years before state-owned Emirates places a new order for the world’s largest jetliner, the airline’s president said on Monday. https://www.reuters.com/article/emirat...

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by Taxi645
Sun Nov 12, 2017 2:50 pm
Forum: Civil Aviation
Topic: How will Airbus address the A350's future weight problem?
Replies: 6
Views: 4595

How will Airbus address the A350's future weight problem?

Now I will first admit that the topic title is slightly dramatic, but I'll explain. The A350-900 and 1000 now have 8.100 and 7.950nm of range, which is already more then plenty for the vast majority of missions. Furthermore at sub 65m wingspan, the same as the A330NEO at 251T MTOW, the A350 has an i...

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