Moderators: jsumali2, richierich, ua900, PanAm_DC10, hOMSaR

 
Misterven1
Topic Author
Posts: 23
Joined: Sun May 20, 2018 7:30 pm

Future VLA-aircraft

Sun Feb 21, 2021 1:29 pm

The end is nearing for Boeing 747 and Airbus A380, I am curious how we can see in the future whether there is room for large VLA aircraft in global aviation. Sometimes I think about Keesje's idea about a double-deck Eco-liner with 2 engines, why would that ever be possible to really develop such a device.

The 777-9X is one of the longest Boeing ever built, but I doubt whether a longer plane than Boeing 777-9X is a good opportunity to earn good money. On the other hand, this is unwise due to security and FAA requirements, but can also cause problems at certain airports due to infrastructure. Longer and larger aircraft also require high takeoff weights and longer runways. But the big question for airlines is also whether it is profitable to have a very large and long aircraft in their fleet. Development of Boeing 777-10X and Airbus A350-2000 was also discussed, but these have been put on hold for the time being due to very little interest among airlines.

Well, a two-engined double-deck plane could be a very good option, but not as big as Airbus A380, but slightly smaller than Boeing 747. This jet should have at least 400-600 passengers over a distance of 6,000-7,000nm and the engines. are as heavy as those of Boeing 777X. This option would be very interesting for Emirates to be able to replace all Airbus A380s in the future. Whether it is also interesting for other airlines, but also the question of whether they ever want to purchase a double-decker aircraft.

Perhaps the Blended Wing aircraft is a very interesting to take a closer look at whether it is actually feasible because of environmental aspects and cost-effectiveness. KLM and all authorities involved are working on this to see whether such an idea can really be used on the drawing board and further developed at an aircraft manufacturer Airbus or Boeing. That project is called V-flying. This aircraft could carry at least 300-400 passengers in 3 class versions: Business Class, Economy Premium and Economy Class. If this project really becomes reality, this aircraft will be a very good replacement for Boeing 787, Boeing 777X, Airbus A350s and flight distance I estimate at 8000 nm. Few details are still known about V-flying. Youtube: https://www.youtube.com/watch?v=a4ITMljykkg Info: https://en.wikipedia.org/wiki/Flying-V

I really don't see an aircraft with 800-1000 or more than 1000 passengers being developed anymore, so it is just really not profitable and has received a very limited business case. Some major airlines use the Airbus A380 sparingly on their lines, which were very busy. The Airbus A380 was indeed not a great sales success of Airbus, so many adjustments were required at certain airports in order to receive a large double-deck aircraft. It is very difficult to fill such a large plane with passengers and a full Airbus A380 every day is really impossible.

My conclusion is that a very large VLA projects was developed too early, which it wasn't a big market for either. In any case, a four-engine VLA aircraft is too expensive, very much maintained, consumes more kerosene than a two-engine aircraft. It is not profitable for airlines to employ such a very large double-decker aircraft at the moment.
Airbus A380 is specially built for very busy hubs that transport passengers from major airport A to other major airport B. A half-full Airbus A380 is also not really interesting for the airline to continue flying. Airbus misguided the market where they could compete with the Boeing 747.
 
SRQLOT
Posts: 632
Joined: Sat Nov 04, 2017 6:05 pm

Re: Future VLA-aircraft

Sun Feb 21, 2021 1:55 pm

Thanks for making a post on this, and yes I though about what will be the future of VLAs. I mean we are about to hit 8 billion people on this planet! And soon it will be 9 and not long after 10 billion! So unless this planet will become like in Elysium where 99.99 will be dirt poor what will we fly on? Will they all be on A320/1 and 737-8/9/10s!?!?

In a couple of years we will have threads just like on the 757 and how Boeing should restart the line, but instead it will be about the 747!! I think airlines are being a bit short sighted, with cancelling or delaying 777x deliveries, and allowing the 747 and A380 to die. We will have slot caps at airports sooner then later..

I do hope the BWB concept becomes a reality, but it will probably be narrow bodies for the rest of my life, and 787/350s here and there.
LO LH CL BA AZ WN UA DL AA B6 NK G4 F9
717 733/7/8/9/M8 744 752/3 763 772 788 319/20/21 332/3 M90 RJ85 CR9 Q400 E70/75/95 (PA28,152)
 
OKCPanda
Posts: 8
Joined: Mon Feb 17, 2020 12:15 pm

Re: Future VLA-aircraft

Sun Feb 21, 2021 1:56 pm

The thing with VLAs and specifically double deckers is you have to "Go big or go home". There is such a weight penalty adding in another floor that you might as well go for the biggest aircraft you can make and that can be supported by ground infrastructure. Even without Covid, the prospect for VLAs was poor.
 
MIflyer12
Posts: 9611
Joined: Mon Feb 18, 2013 11:58 pm

Re: Future VLA-aircraft

Sun Feb 21, 2021 2:06 pm

SRQLOT wrote:
Thanks for making a post on this, and yes I though about what will be the future of VLAs. I mean we are about to hit 8 billion people on this planet! And soon it will be 9 and not long after 10 billion! So unless this planet will become like in Elysium where 99.99 will be dirt poor what will we fly on? Will they all be on A320/1 and 737-8/9/10s!?!?

In a couple of years we will have threads just like on the 757 and how Boeing should restart the line, but instead it will be about the 747!! I think airlines are being a bit short sighted, with cancelling or delaying 777x deliveries, and allowing the 747 and A380 to die. We will have slot caps at airports sooner then later..


The phrase you need - that Airbus lacked lo those many years and Billions of Euros ago - is route fragmentation. If slots to operate LHR-PEK (for example) are too expensive to continue adding frequencies with A350/787/77X, then people flying xxx-LHR-PEK will be shunted to other hubs and LHR-PEK will be sold as O&D. So you're looking at the number of O&D airport pairs with slots much too expensive on at least one end, expensive enough to force B or A to spend $15+ Billion to develop a new VLA, and force carriers to spend $ Billions to buy them at least a dozen at a time, and with passengers willing to pay those premiums instead of using a connection. Good luck with that! Check flight ops at LHR and LGW. Do you see nothing but 748s and A380s headed out every minute of operation? No, you do not.
 
Misterven1
Topic Author
Posts: 23
Joined: Sun May 20, 2018 7:30 pm

Re: Future VLA-aircraft

Sun Feb 21, 2021 2:23 pm

OKCPanda wrote:
The thing with VLAs and specifically double deckers is you have to "Go big or go home". There is such a weight penalty adding in another floor that you might as well go for the biggest aircraft you can make and that can be supported by ground infrastructure. Even without Covid, the prospect for VLAs was poor.


Yes I thought so too. But at the moment I think a double deck plane is not yet profitable for major airlines such as Emirates or Lufthansa. As we are still in corona pandemic, the market has now turned so negative for very large aircraft. After the corona pandemic, the market will slowly recover, mainly vaccinating people against corona. I predict that in 2040-2050 there will be a market for VLA with 500-800 passengers if no new pandemics break out.
 
morrisond
Posts: 3418
Joined: Thu Jan 07, 2010 12:22 am

Re: Future VLA-aircraft

Sun Feb 21, 2021 2:25 pm

Misterven1 wrote:
The end is nearing for Boeing 747 and Airbus A380, I am curious how we can see in the future whether there is room for large VLA aircraft in global aviation. Sometimes I think about Keesje's idea about a double-deck Eco-liner with 2 engines, why would that ever be possible to really develop such a device.

The 777-9X is one of the longest Boeing ever built, but I doubt whether a longer plane than Boeing 777-9X is a good opportunity to earn good money. On the other hand, this is unwise due to security and FAA requirements, but can also cause problems at certain airports due to infrastructure. Longer and larger aircraft also require high takeoff weights and longer runways. But the big question for airlines is also whether it is profitable to have a very large and long aircraft in their fleet. Development of Boeing 777-10X and Airbus A350-2000 was also discussed, but these have been put on hold for the time being due to very little interest among airlines.

Well, a two-engined double-deck plane could be a very good option, but not as big as Airbus A380, but slightly smaller than Boeing 747. This jet should have at least 400-600 passengers over a distance of 6,000-7,000nm and the engines. are as heavy as those of Boeing 777X. This option would be very interesting for Emirates to be able to replace all Airbus A380s in the future. Whether it is also interesting for other airlines, but also the question of whether they ever want to purchase a double-decker aircraft.

Perhaps the Blended Wing aircraft is a very interesting to take a closer look at whether it is actually feasible because of environmental aspects and cost-effectiveness. KLM and all authorities involved are working on this to see whether such an idea can really be used on the drawing board and further developed at an aircraft manufacturer Airbus or Boeing. That project is called V-flying. This aircraft could carry at least 300-400 passengers in 3 class versions: Business Class, Economy Premium and Economy Class. If this project really becomes reality, this aircraft will be a very good replacement for Boeing 787, Boeing 777X, Airbus A350s and flight distance I estimate at 8000 nm. Few details are still known about V-flying. Youtube: https://www.youtube.com/watch?v=a4ITMljykkg Info: https://en.wikipedia.org/wiki/Flying-V

I really don't see an aircraft with 800-1000 or more than 1000 passengers being developed anymore, so it is just really not profitable and has received a very limited business case. Some major airlines use the Airbus A380 sparingly on their lines, which were very busy. The Airbus A380 was indeed not a great sales success of Airbus, so many adjustments were required at certain airports in order to receive a large double-deck aircraft. It is very difficult to fill such a large plane with passengers and a full Airbus A380 every day is really impossible.

My conclusion is that a very large VLA projects was developed too early, which it wasn't a big market for either. In any case, a four-engine VLA aircraft is too expensive, very much maintained, consumes more kerosene than a two-engine aircraft. It is not profitable for airlines to employ such a very large double-decker aircraft at the moment.
Airbus A380 is specially built for very busy hubs that transport passengers from major airport A to other major airport B. A half-full Airbus A380 is also not really interesting for the airline to continue flying. Airbus misguided the market where they could compete with the Boeing 747.


BTW - welcome to Anet - you have been making some great posts.

I think if a new VLA happens it will have to be something like a Blended wing (by some reports about 25% more efficient than tube and wing) that is a step change in fuel efficiency and may be driven by environmental concerns. It may be the right shape for a hydrogen powered aircraft where you need lots of internal volume to hold the tanks. BWB's have excesses of that and it should be easier to figure that out on a larger scale lower volume aircraft first due to complexities of production and pressurization. Although it would not be hard to have Circular internal pressured passenger/Cockpit sections and cargo bays.

They may not be that large though as once envisioned - just too hard to fill and too inflexible. You would have to guess they would max out at about 500 seats. It could be what we see in the 2040's though as replacements for 787/777X and A350 which will be well over 30 years since launch with 1,000's more have been built and delivered by both sides by the time of EIS of a replacement.

Boeing will be very busy probably until 2035 with NMA/NSA and a probable update of 787 with new engines and Aero cleanup/weight reduction and Airbus with further development of A320/A220 and update of A350 starting sometime around the end of this decade.
 
User avatar
lightsaber
Moderator
Posts: 22386
Joined: Wed Jan 19, 2005 10:55 pm

Re: Future VLA-aircraft

Sun Feb 21, 2021 2:39 pm

VLAs are en enigma. They work by carrying each passenger cheaper than smaller aircraft. Due to the ability to upgauge any airport (e.g., A319 to A321), they are not yet required.

The advantage of a VLA is that it can be very economical per passenger. My issue with the A380 is it was too small. Bear with me.
1. Stairways. These are required for a second deck, but take up substantial weight and space. This makes going from one deck to two inefficient initially. It takes a larger aircraft to "pay for the weight."
2. Elevators, fire systems, and plumbing on two decks also has a weight delta.
3. Initial large increase in surface area. This is an increase in drag.

The BWB sticks to one deck (in any viable concept I've seen), but has concerns on evacuation. I believe the evacuation problem has been solved. basically stairs analogous to the attic stairs to get to the top of the aircraft and then everyone walks off except for people near the front or back who have doors to use more typical slides.

What has to happen is far less surface area per passenger and less weight per passenger to get down costs. Now the A380 had incredibly great crew efficiency. e.g. a 787 and an A380 need the same quantity of pilots for the same flight. The same number of people to service the lavatories and same number of people to fuel or put water on the aircraft, just a little more time due to quantity. One must remember there are a lot of labor hours wasted in setup and disassembly instead of purely transferring the fluids. e.g., driving the truck to the aircraft (even if the truck is just carrying the people to do the job as all the equipment is in the aircraft pad. As an expert in fluids, my hat is off to the A380 plumbing engineers. :praise:

My conclusion is the A380 was too short. I would argue also just a fraction too narrow too. What?!? Yes, too small. When I look at the cross section, a tiny amount more weight and width gives 11 across main deck and 9 across top deck. They were too fixed on a market size instead of "what was the cost of a small increase?" Now as soon as that minor increase in width happens, a longer length is optimal. But also, the A380 lost too much space to stairways and other services to service the top deck. That length meant the 77W carries a passenger for less fuel per trip than the A380! :wideeyed:

Here is a table of fuel burn per hour:
https://alliknowaviation.com/2019/12/14 ... -aircraft/

77W is 7500 kg/hr for ~360 passengers (20.8 kg per hour per pax) and the A380 at 11,000 kg/hr for 519 seats (21.19 kg/hr per seat). Ok, not much differnce. But why?
1. A380 engines are same tech
2. Wing of A380 isn't optimal, a consequence of the 80m box (it really needs folding wingtips)
3. All the weight added for two decks that wasn't optimal.

So how to make an A380 much more efficient per passenger?
1. Get the cross section more optimal. A little more width gets 11 across bottom deck and 9 across top (in Y).
2. Optimize the stairways. Now this is 20/20 hindsight, but the cruise ship entry is lovely, but too costly for air travel. The rear stairs are bad.
3. Due to advances in 3D modeling tools, we could get better packaging of crew rests, In particular at the front and tail of the aircraft. Crew rests are needed. With modern CFRP bulkheads, so much space in that tail could be used today. More seats up near the front.
4. Stretch. Since there is a cost for two decks, there is a minimum economical size. In my opinion the A380 was too short. I am a fan of the Udvar-Hazy 85m length to 89m length. The choice of the 80m box was too short
5. More wing. Ok, first obviously it will be CFRP, but also we need folding wingtips. More than an 80m width is far too much real estate wasted at the gate. Too many airports are running out of real estate, so the gates much get more efficient.

I haven't looked into what the natural maximum wing span is. My opinion is that if 30+ of the large airports could accommodate an aircraft is sufficient. But there are certain airports required if any are to sell and that is: PEK & PKX, PVG, NRT, SIN, HKG, SYD, MEL, KG, LAX, JFK, LHR, CDG, FRA, DXB, BKK, and IST. I'm sorry if your favorite airport was listed, but the reality is, not every city must be served. J

For the business case of a VLA, not every major city must be served. Just enough. For example, India didn't allow the A380 at first, so unfortunately proved they are not part of the mandatory cities to service the type. The reality is one only has to service trunk routes between the USA, Europe, China, Japan, Thailand, and Australia as the minimum. Now ideally we add in South America, Africa, Indonesia, Malaysia, India, and secondary cities in the Emirates model (for example).

The BWB has merit and is a design that benefits from scale, but I have seen as little as 250 seat examples that would be competitive. The lack of a rudder forces 3 or 4 engines (one must design for the engine out condition which is over-powering in a twin), which will push the concept up in size very quickly. The BWB has better environmentalism, so I'm not sure on why that comment. It just needs to be big due to the constraints on the first examples.

So a double decker really doesn't work below 600 seats. :wideeyed:
A BWB works, but today I would say a minimum of 350 seats and if someone comes back and says 450, I would accept that (after they performed a detailed design study).

But for now, there just isn't enough demand. The 779, despite the incredibly advanced engines (a generation ahead of any other, in my opinion), is going to struggle. At this time we'll look at engine PiPs on the 787 and A350 as the main growth path (adding 777x engine technology back down to their engines, e.g., variable turbine cooling, CMC turbine inlet guide vanes, the more advanced low turbine, compressor blade shaping, but not the higher mach # compressors, better compressor and turbine matching between high and low spools, as those are not retrofittable, those features requiresa new engine architecture). I also *really* like Pratt's fan nozzle concept for reasons that are not yet public that I probably shouldn't discuss due to ancient NDAs (I used to work in Pratt's combustors, augmentors, and nozzles R&D group a long time ago).

We'll have VLAs, but it must be a larger VLA to gain per seat efficiency. The per seat efficiency must be so amazing that it is an easy win on trunk routes and that requires a large aircraft which limits the numbers sold.

Lightsaber
7 months without TV. The best decision of my life.
 
randomdude83
Posts: 100
Joined: Fri Feb 01, 2019 5:52 pm

Re: Future VLA-aircraft

Sun Feb 21, 2021 2:48 pm

I always thought that at some point our population is indeed growing and it’s almost guaranteed a next generation VLA will have to be developed right after all the brand new massive airports reach peak congestion and out of slots for narrow aircraft.

I just think this might be something like 40 to 50 years from now. That’s how much airport capacity has been built so far.

I always felt Boeing do have a nice pattern to what the next aircraft will be. Double deckers are not efficient space wise. Too much of passengers, not enough cargo.

To get an equal growth pac/cargo you have to think wider.

Not blended wing.

Just what Boeing has been doing all along

Think 757 (3-3)
767 (2-3–2)
777 (3-4-3)
7777 (3-4-4-3) now you you can take three cargo containers side by side.

But then you’ll need one heck of an engine and a wing to get that off but at the same time, Boeing’s progress on The 777x with more wing and less thrust than the 77w is a neat game changer that could help with the development of such an aircraft.

I’m Basically describing a 777 and a half wide aircraft which isn’t totally crazy.
 
GalaxyFlyer
Posts: 7777
Joined: Fri Jan 01, 2016 4:44 am

Re: Future VLA-aircraft

Sun Feb 21, 2021 3:04 pm

Has anyone here heard of flight shaming? Politics will kill massive tourism, which is what drives VLAs. Business travel, while profitable doesn’t require a VLA, but it’s numbers alone, except on very few routes. If anything we’ve reached peak airliner and will retreat to 787-A350 types for the next 30 years.
 
Strato2
Posts: 617
Joined: Sat Sep 24, 2016 3:52 pm

Re: Future VLA-aircraft

Sun Feb 21, 2021 3:11 pm

lightsaber wrote:
That length meant the 77W carries a passenger for less fuel per trip than the A380! :wideeyed:

Here is a table of fuel burn per hour:
https://alliknowaviation.com/2019/12/14 ... -aircraft/

77W is 7500 kg/hr for ~360 passengers (20.8 kg per hour per pax) and the A380 at 11,000 kg/hr for 519 seats (21.19 kg/hr per seat). Ok, not much differnce. But why?

Lightsaber


Using your numbers and known cabin areas (A380 633m2, 300ER 338m2) gives a cabin area per pax of 1,219m2 for the A380 and 0,938 for the 300ER. The A380 has 30% more space per pax. An apples to golf balls comparison. With equal seating density you will have 674 seats on the A380 and per pax consumption of 16,32kg/hr per seat.
 
btfarrwm
Posts: 147
Joined: Fri May 06, 2011 5:50 am

Re: Future VLA-aircraft

Sun Feb 21, 2021 3:20 pm

lightsaber wrote:
The BWB sticks to one deck (in any viable concept I've seen), but has concerns on evacuation. I believe the evacuation problem has been solved. basically stairs analogous to the attic stairs to get to the top of the aircraft and then everyone walks off except for people near the front or back who have doors to use more typical slides.
Lightsaber


How could people evacuating an aircraft in an emergency be expected to climb stairs? Elderly and injured people would never be able to do that in a timely fashion.
 
Elementalism
Posts: 657
Joined: Sat Jun 10, 2017 4:03 am

Re: Future VLA-aircraft

Sun Feb 21, 2021 3:27 pm

Misterven1 wrote:
The end is nearing for Boeing 747 and Airbus A380, I am curious how we can see in the future whether there is room for large VLA aircraft in global aviation. Sometimes I think about Keesje's idea about a double-deck Eco-liner with 2 engines, why would that ever be possible to really develop such a device.

The 777-9X is one of the longest Boeing ever built, but I doubt whether a longer plane than Boeing 777-9X is a good opportunity to earn good money. On the other hand, this is unwise due to security and FAA requirements, but can also cause problems at certain airports due to infrastructure. Longer and larger aircraft also require high takeoff weights and longer runways. But the big question for airlines is also whether it is profitable to have a very large and long aircraft in their fleet. Development of Boeing 777-10X and Airbus A350-2000 was also discussed, but these have been put on hold for the time being due to very little interest among airlines.

Well, a two-engined double-deck plane could be a very good option, but not as big as Airbus A380, but slightly smaller than Boeing 747. This jet should have at least 400-600 passengers over a distance of 6,000-7,000nm and the engines. are as heavy as those of Boeing 777X. This option would be very interesting for Emirates to be able to replace all Airbus A380s in the future. Whether it is also interesting for other airlines, but also the question of whether they ever want to purchase a double-decker aircraft.

Perhaps the Blended Wing aircraft is a very interesting to take a closer look at whether it is actually feasible because of environmental aspects and cost-effectiveness. KLM and all authorities involved are working on this to see whether such an idea can really be used on the drawing board and further developed at an aircraft manufacturer Airbus or Boeing. That project is called V-flying. This aircraft could carry at least 300-400 passengers in 3 class versions: Business Class, Economy Premium and Economy Class. If this project really becomes reality, this aircraft will be a very good replacement for Boeing 787, Boeing 777X, Airbus A350s and flight distance I estimate at 8000 nm. Few details are still known about V-flying. Youtube: https://www.youtube.com/watch?v=a4ITMljykkg Info: https://en.wikipedia.org/wiki/Flying-V

I really don't see an aircraft with 800-1000 or more than 1000 passengers being developed anymore, so it is just really not profitable and has received a very limited business case. Some major airlines use the Airbus A380 sparingly on their lines, which were very busy. The Airbus A380 was indeed not a great sales success of Airbus, so many adjustments were required at certain airports in order to receive a large double-deck aircraft. It is very difficult to fill such a large plane with passengers and a full Airbus A380 every day is really impossible.

My conclusion is that a very large VLA projects was developed too early, which it wasn't a big market for either. In any case, a four-engine VLA aircraft is too expensive, very much maintained, consumes more kerosene than a two-engine aircraft. It is not profitable for airlines to employ such a very large double-decker aircraft at the moment.
Airbus A380 is specially built for very busy hubs that transport passengers from major airport A to other major airport B. A half-full Airbus A380 is also not really interesting for the airline to continue flying. Airbus misguided the market where they could compete with the Boeing 747.


I agree with this 110%. I feel like the A380 was 20-30 years too early. And engine technology needed to catch up to allow for a two engine variant. I think VLA will be back within my lifetime but with two engines. This world is becoming more interconnected and I could see some legs, particularily having 400-600pax demand. But 4 engines is too expensive to make it worth it.

The next 10-15 years with the 777x program will tell us if VLA will be back within the next 50 years imo.
 
Elementalism
Posts: 657
Joined: Sat Jun 10, 2017 4:03 am

Re: Future VLA-aircraft

Sun Feb 21, 2021 3:31 pm

lightsaber wrote:
VLAs are en enigma. They work by carrying each passenger cheaper than smaller aircraft. Due to the ability to upgauge any airport (e.g., A319 to A321), they are not yet required.

The advantage of a VLA is that it can be very economical per passenger. My issue with the A380 is it was too small. Bear with me.
1. Stairways. These are required for a second deck, but take up substantial weight and space. This makes going from one deck to two inefficient initially. It takes a larger aircraft to "pay for the weight."
2. Elevators, fire systems, and plumbing on two decks also has a weight delta.
3. Initial large increase in surface area. This is an increase in drag.

The BWB sticks to one deck (in any viable concept I've seen), but has concerns on evacuation. I believe the evacuation problem has been solved. basically stairs analogous to the attic stairs to get to the top of the aircraft and then everyone walks off except for people near the front or back who have doors to use more typical slides.

What has to happen is far less surface area per passenger and less weight per passenger to get down costs. Now the A380 had incredibly great crew efficiency. e.g. a 787 and an A380 need the same quantity of pilots for the same flight. The same number of people to service the lavatories and same number of people to fuel or put water on the aircraft, just a little more time due to quantity. One must remember there are a lot of labor hours wasted in setup and disassembly instead of purely transferring the fluids. e.g., driving the truck to the aircraft (even if the truck is just carrying the people to do the job as all the equipment is in the aircraft pad. As an expert in fluids, my hat is off to the A380 plumbing engineers. :praise:

My conclusion is the A380 was too short. I would argue also just a fraction too narrow too. What?!? Yes, too small. When I look at the cross section, a tiny amount more weight and width gives 11 across main deck and 9 across top deck. They were too fixed on a market size instead of "what was the cost of a small increase?" Now as soon as that minor increase in width happens, a longer length is optimal. But also, the A380 lost too much space to stairways and other services to service the top deck. That length meant the 77W carries a passenger for less fuel per trip than the A380! :wideeyed:

Here is a table of fuel burn per hour:
https://alliknowaviation.com/2019/12/14 ... -aircraft/

77W is 7500 kg/hr for ~360 passengers (20.8 kg per hour per pax) and the A380 at 11,000 kg/hr for 519 seats (21.19 kg/hr per seat). Ok, not much differnce. But why?
1. A380 engines are same tech
2. Wing of A380 isn't optimal, a consequence of the 80m box (it really needs folding wingtips)
3. All the weight added for two decks that wasn't optimal.

So how to make an A380 much more efficient per passenger?
1. Get the cross section more optimal. A little more width gets 11 across bottom deck and 9 across top (in Y).
2. Optimize the stairways. Now this is 20/20 hindsight, but the cruise ship entry is lovely, but too costly for air travel. The rear stairs are bad.
3. Due to advances in 3D modeling tools, we could get better packaging of crew rests, In particular at the front and tail of the aircraft. Crew rests are needed. With modern CFRP bulkheads, so much space in that tail could be used today. More seats up near the front.
4. Stretch. Since there is a cost for two decks, there is a minimum economical size. In my opinion the A380 was too short. I am a fan of the Udvar-Hazy 85m length to 89m length. The choice of the 80m box was too short
5. More wing. Ok, first obviously it will be CFRP, but also we need folding wingtips. More than an 80m width is far too much real estate wasted at the gate. Too many airports are running out of real estate, so the gates much get more efficient.

I haven't looked into what the natural maximum wing span is. My opinion is that if 30+ of the large airports could accommodate an aircraft is sufficient. But there are certain airports required if any are to sell and that is: PEK & PKX, PVG, NRT, SIN, HKG, SYD, MEL, KG, LAX, JFK, LHR, CDG, FRA, DXB, BKK, and IST. I'm sorry if your favorite airport was listed, but the reality is, not every city must be served. J

For the business case of a VLA, not every major city must be served. Just enough. For example, India didn't allow the A380 at first, so unfortunately proved they are not part of the mandatory cities to service the type. The reality is one only has to service trunk routes between the USA, Europe, China, Japan, Thailand, and Australia as the minimum. Now ideally we add in South America, Africa, Indonesia, Malaysia, India, and secondary cities in the Emirates model (for example).

The BWB has merit and is a design that benefits from scale, but I have seen as little as 250 seat examples that would be competitive. The lack of a rudder forces 3 or 4 engines (one must design for the engine out condition which is over-powering in a twin), which will push the concept up in size very quickly. The BWB has better environmentalism, so I'm not sure on why that comment. It just needs to be big due to the constraints on the first examples.

So a double decker really doesn't work below 600 seats. :wideeyed:
A BWB works, but today I would say a minimum of 350 seats and if someone comes back and says 450, I would accept that (after they performed a detailed design study).

But for now, there just isn't enough demand. The 779, despite the incredibly advanced engines (a generation ahead of any other, in my opinion), is going to struggle. At this time we'll look at engine PiPs on the 787 and A350 as the main growth path (adding 777x engine technology back down to their engines, e.g., variable turbine cooling, CMC turbine inlet guide vanes, the more advanced low turbine, compressor blade shaping, but not the higher mach # compressors, better compressor and turbine matching between high and low spools, as those are not retrofittable, those features requiresa new engine architecture). I also *really* like Pratt's fan nozzle concept for reasons that are not yet public that I probably shouldn't discuss due to ancient NDAs (I used to work in Pratt's combustors, augmentors, and nozzles R&D group a long time ago).

We'll have VLAs, but it must be a larger VLA to gain per seat efficiency. The per seat efficiency must be so amazing that it is an easy win on trunk routes and that requires a large aircraft which limits the numbers sold.

Lightsaber


My understanding is the A380 was built with a -900 and -1000 in mind. But the demand never materialized. The -800 has everything for the larger aircraft(including weight). Which didnt help it when it came to economics.
 
Elementalism
Posts: 657
Joined: Sat Jun 10, 2017 4:03 am

Re: Future VLA-aircraft

Sun Feb 21, 2021 3:33 pm

randomdude83 wrote:
I always thought that at some point our population is indeed growing and it’s almost guaranteed a next generation VLA will have to be developed right after all the brand new massive airports reach peak congestion and out of slots for narrow aircraft.

I just think this might be something like 40 to 50 years from now. That’s how much airport capacity has been built so far.

I always felt Boeing do have a nice pattern to what the next aircraft will be. Double deckers are not efficient space wise. Too much of passengers, not enough cargo.

To get an equal growth pac/cargo you have to think wider.

Not blended wing.

Just what Boeing has been doing all along

Think 757 (3-3)
767 (2-3–2)
777 (3-4-3)
7777 (3-4-4-3) now you you can take three cargo containers side by side.

But then you’ll need one heck of an engine and a wing to get that off but at the same time, Boeing’s progress on The 777x with more wing and less thrust than the 77w is a neat game changer that could help with the development of such an aircraft.

I’m Basically describing a 777 and a half wide aircraft which isn’t totally crazy.

For me it isnt really population growth. It is emerging markets with a middle class that can afford to fly. There are still large swaths of the world that hasnt attained a level of wealth that allows them to fly. This will happen over the next century and demand for flying if population stayed the same will continue to climb(once out of this pandemic).
 
Misterven1
Topic Author
Posts: 23
Joined: Sun May 20, 2018 7:30 pm

Re: Future VLA-aircraft

Sun Feb 21, 2021 3:35 pm

lightsaber wrote:
VLAs are en enigma. They work by carrying each passenger cheaper than smaller aircraft. Due to the ability to upgauge any airport (e.g., A319 to A321), they are not yet required.

The advantage of a VLA is that it can be very economical per passenger. My issue with the A380 is it was too small. Bear with me.
1. Stairways. These are required for a second deck, but take up substantial weight and space. This makes going from one deck to two inefficient initially. It takes a larger aircraft to "pay for the weight."
2. Elevators, fire systems, and plumbing on two decks also has a weight delta.
3. Initial large increase in surface area. This is an increase in drag.

The BWB sticks to one deck (in any viable concept I've seen), but has concerns on evacuation. I believe the evacuation problem has been solved. basically stairs analogous to the attic stairs to get to the top of the aircraft and then everyone walks off except for people near the front or back who have doors to use more typical slides.

What has to happen is far less surface area per passenger and less weight per passenger to get down costs. Now the A380 had incredibly great crew efficiency. e.g. a 787 and an A380 need the same quantity of pilots for the same flight. The same number of people to service the lavatories and same number of people to fuel or put water on the aircraft, just a little more time due to quantity. One must remember there are a lot of labor hours wasted in setup and disassembly instead of purely transferring the fluids. e.g., driving the truck to the aircraft (even if the truck is just carrying the people to do the job as all the equipment is in the aircraft pad. As an expert in fluids, my hat is off to the A380 plumbing engineers. :praise:

My conclusion is the A380 was too short. I would argue also just a fraction too narrow too. What?!? Yes, too small. When I look at the cross section, a tiny amount more weight and width gives 11 across main deck and 9 across top deck. They were too fixed on a market size instead of "what was the cost of a small increase?" Now as soon as that minor increase in width happens, a longer length is optimal. But also, the A380 lost too much space to stairways and other services to service the top deck. That length meant the 77W carries a passenger for less fuel per trip than the A380! :wideeyed:

Here is a table of fuel burn per hour:
https://alliknowaviation.com/2019/12/14 ... -aircraft/

77W is 7500 kg/hr for ~360 passengers (20.8 kg per hour per pax) and the A380 at 11,000 kg/hr for 519 seats (21.19 kg/hr per seat). Ok, not much differnce. But why?
1. A380 engines are same tech
2. Wing of A380 isn't optimal, a consequence of the 80m box (it really needs folding wingtips)
3. All the weight added for two decks that wasn't optimal.

So how to make an A380 much more efficient per passenger?
1. Get the cross section more optimal. A little more width gets 11 across bottom deck and 9 across top (in Y).
2. Optimize the stairways. Now this is 20/20 hindsight, but the cruise ship entry is lovely, but too costly for air travel. The rear stairs are bad.
3. Due to advances in 3D modeling tools, we could get better packaging of crew rests, In particular at the front and tail of the aircraft. Crew rests are needed. With modern CFRP bulkheads, so much space in that tail could be used today. More seats up near the front.
4. Stretch. Since there is a cost for two decks, there is a minimum economical size. In my opinion the A380 was too short. I am a fan of the Udvar-Hazy 85m length to 89m length. The choice of the 80m box was too short
5. More wing. Ok, first obviously it will be CFRP, but also we need folding wingtips. More than an 80m width is far too much real estate wasted at the gate. Too many airports are running out of real estate, so the gates much get more efficient.

I haven't looked into what the natural maximum wing span is. My opinion is that if 30+ of the large airports could accommodate an aircraft is sufficient. But there are certain airports required if any are to sell and that is: PEK & PKX, PVG, NRT, SIN, HKG, SYD, MEL, KG, LAX, JFK, LHR, CDG, FRA, DXB, BKK, and IST. I'm sorry if your favorite airport was listed, but the reality is, not every city must be served. J

For the business case of a VLA, not every major city must be served. Just enough. For example, India didn't allow the A380 at first, so unfortunately proved they are not part of the mandatory cities to service the type. The reality is one only has to service trunk routes between the USA, Europe, China, Japan, Thailand, and Australia as the minimum. Now ideally we add in South America, Africa, Indonesia, Malaysia, India, and secondary cities in the Emirates model (for example).

The BWB has merit and is a design that benefits from scale, but I have seen as little as 250 seat examples that would be competitive. The lack of a rudder forces 3 or 4 engines (one must design for the engine out condition which is over-powering in a twin), which will push the concept up in size very quickly. The BWB has better environmentalism, so I'm not sure on why that comment. It just needs to be big due to the constraints on the first examples.

So a double decker really doesn't work below 600 seats. :wideeyed:
A BWB works, but today I would say a minimum of 350 seats and if someone comes back and says 450, I would accept that (after they performed a detailed design study).

But for now, there just isn't enough demand. The 779, despite the incredibly advanced engines (a generation ahead of any other, in my opinion), is going to struggle. At this time we'll look at engine PiPs on the 787 and A350 as the main growth path (adding 777x engine technology back down to their engines, e.g., variable turbine cooling, CMC turbine inlet guide vanes, the more advanced low turbine, compressor blade shaping, but not the higher mach # compressors, better compressor and turbine matching between high and low spools, as those are not retrofittable, those features requiresa new engine architecture). I also *really* like Pratt's fan nozzle concept for reasons that are not yet public that I probably shouldn't discuss due to ancient NDAs (I used to work in Pratt's combustors, augmentors, and nozzles R&D group a long time ago).

We'll have VLAs, but it must be a larger VLA to gain per seat efficiency. The per seat efficiency must be so amazing that it is an easy win on trunk routes and that requires a large aircraft which limits the numbers sold.

Lightsaber


I have read your story carefully. I also think that is a mystery with VLA regarding the Airbus A380. The A380 is quite a large aircraft with a long range, but only suitable for very busy routes where large airports are suitable for handling. In comparison, the Airbus A380 was only purchased by major airlines that used super-busy routes.

From an environmental point of view, I really don't think Airbus A380 is more economical than smaller aircraft ... depending on the seat it is often more expensive to use. I think the Airbus A380 uses just as much kerosene as a Boeing 747-8. In itself, Airbus A380 is really a flop that Airbus has now developed further.

I see a bit more in BWB than in a very large double-decker aircraft because in a BWB there is more room for passengers and cargo and also saves more environmental benefits such as kerosene savings. This allows a BWB to fly further than a double-decker aircraft, for example from Amsterdam to Melbourne in Australia. And I think a BWB can give passengers more comfort than in a narrow and long plane. Then you have the feeling that you are not sitting in a tight chair or constantly sitting at the window. In a BWB there are also more possibilities for a company to place a private Business class apartment (kind of suite). In a Boeing 777 or Airbus A350, the space is sufficient, but in a Business Class is still somewhat limited for a demanding business traveler.
 
User avatar
NameOmitted
Posts: 1026
Joined: Sun Oct 23, 2016 7:59 pm

Re: Future VLA-aircraft

Sun Feb 21, 2021 3:36 pm

I think one of the significant challenges overcome is the speed of passenger loading and unloading. An airport tarmac is some of the most expensive bits of real estate there is, and a large aircraft can sit there for 90 minutes.

A large trainset, with its multiple doors, can unload and load 1,000 people in 10 minutes.
 
User avatar
scbriml
Posts: 19927
Joined: Wed Jul 02, 2003 10:37 pm

Re: Future VLA-aircraft

Sun Feb 21, 2021 3:41 pm

btfarrwm wrote:
lightsaber wrote:
The BWB sticks to one deck (in any viable concept I've seen), but has concerns on evacuation. I believe the evacuation problem has been solved. basically stairs analogous to the attic stairs to get to the top of the aircraft and then everyone walks off except for people near the front or back who have doors to use more typical slides.
Lightsaber


How could people evacuating an aircraft in an emergency be expected to climb stairs? Elderly and injured people would never be able to do that in a timely fashion.


The same way that elderly and injured people are expected to evacuate a burning plane today.
Time flies like an arrow. Fruit flies like a banana!
There are 10 types of people in the World - those that understand binary and those that don't.
 
Misterven1
Topic Author
Posts: 23
Joined: Sun May 20, 2018 7:30 pm

Re: Future VLA-aircraft

Sun Feb 21, 2021 3:49 pm

Elementalism wrote:
Misterven1 wrote:
The end is nearing for Boeing 747 and Airbus A380, I am curious how we can see in the future whether there is room for large VLA aircraft in global aviation. Sometimes I think about Keesje's idea about a double-deck Eco-liner with 2 engines, why would that ever be possible to really develop such a device.

The 777-9X is one of the longest Boeing ever built, but I doubt whether a longer plane than Boeing 777-9X is a good opportunity to earn good money. On the other hand, this is unwise due to security and FAA requirements, but can also cause problems at certain airports due to infrastructure. Longer and larger aircraft also require high takeoff weights and longer runways. But the big question for airlines is also whether it is profitable to have a very large and long aircraft in their fleet. Development of Boeing 777-10X and Airbus A350-2000 was also discussed, but these have been put on hold for the time being due to very little interest among airlines.

Well, a two-engined double-deck plane could be a very good option, but not as big as Airbus A380, but slightly smaller than Boeing 747. This jet should have at least 400-600 passengers over a distance of 6,000-7,000nm and the engines. are as heavy as those of Boeing 777X. This option would be very interesting for Emirates to be able to replace all Airbus A380s in the future. Whether it is also interesting for other airlines, but also the question of whether they ever want to purchase a double-decker aircraft.

Perhaps the Blended Wing aircraft is a very interesting to take a closer look at whether it is actually feasible because of environmental aspects and cost-effectiveness. KLM and all authorities involved are working on this to see whether such an idea can really be used on the drawing board and further developed at an aircraft manufacturer Airbus or Boeing. That project is called V-flying. This aircraft could carry at least 300-400 passengers in 3 class versions: Business Class, Economy Premium and Economy Class. If this project really becomes reality, this aircraft will be a very good replacement for Boeing 787, Boeing 777X, Airbus A350s and flight distance I estimate at 8000 nm. Few details are still known about V-flying. Youtube: https://www.youtube.com/watch?v=a4ITMljykkg Info: https://en.wikipedia.org/wiki/Flying-V

I really don't see an aircraft with 800-1000 or more than 1000 passengers being developed anymore, so it is just really not profitable and has received a very limited business case. Some major airlines use the Airbus A380 sparingly on their lines, which were very busy. The Airbus A380 was indeed not a great sales success of Airbus, so many adjustments were required at certain airports in order to receive a large double-deck aircraft. It is very difficult to fill such a large plane with passengers and a full Airbus A380 every day is really impossible.

My conclusion is that a very large VLA projects was developed too early, which it wasn't a big market for either. In any case, a four-engine VLA aircraft is too expensive, very much maintained, consumes more kerosene than a two-engine aircraft. It is not profitable for airlines to employ such a very large double-decker aircraft at the moment.
Airbus A380 is specially built for very busy hubs that transport passengers from major airport A to other major airport B. A half-full Airbus A380 is also not really interesting for the airline to continue flying. Airbus misguided the market where they could compete with the Boeing 747.


I agree with this 110%. I feel like the A380 was 20-30 years too early. And engine technology needed to catch up to allow for a two engine variant. I think VLA will be back within my lifetime but with two engines. This world is becoming more interconnected and I could see some legs, particularily having 400-600pax demand. But 4 engines is too expensive to make it worth it.

The next 10-15 years with the 777x program will tell us if VLA will be back within the next 50 years imo.


That's right. I think it is also possible in 30-50 years that there will be a very large biplane with 2 engines instead of 4. Everything depends on which engine type is most suitable for the future VLAs

Perhaps the best thing to do is to start developing a small biplane and see how it fares in global aviation. A small double-decker aircraft will carry at least 300-500 passengers, the same amount as Boeing 747 over a distance of 11,009-15,000 km. This variant is also much cheaper for many airlines, both weight and environmental benefits such as fossil kersoine or hydrogen instead of traditional kersoine. And will also not cause problems for emergency evacuation, for example emergency landing. And also saves a lot of space in a large or small airport.
 
User avatar
ntehrani
Posts: 11
Joined: Wed May 13, 2020 12:56 am

Re: Future VLA-aircraft

Sun Feb 21, 2021 4:16 pm

The 777-9X is likely the biggest airliner we'll see for a very long time. There is still room for incremental improvement, and Boeing will likely stretch production (slowed to a crawl at times, if need be) into the 2040s.
 
tomcat
Posts: 755
Joined: Thu Sep 28, 2000 4:14 am

Re: Future VLA-aircraft

Sun Feb 21, 2021 4:16 pm

lightsaber wrote:
1. Stairways. These are required for a second deck, but take up substantial weight and space. This makes going from one deck to two inefficient initially. It takes a larger aircraft to "pay for the weight."


Which makes me think that current single-aisle aircraft used at their max range have less space wasted for galleys and aisles compared to widebodies, VLA or not. I'm curious to see the area that airlines will allocate to the galleys on the XLR. In the quest for efficiency, I would rather consider single-aisle aircraft rather than VLAs. I also like the twin-fuselage concept. It would be a good alternative to the BWB because it already allows to distribute the fuselage and payload weight across the span, alleviating the max wing bending compared to the current single tubes.

lightsaber wrote:
the 77W carries a passenger for less fuel per trip than the A380! :wideeyed:

Here is a table of fuel burn per hour:
https://alliknowaviation.com/2019/12/14 ... -aircraft/

77W is 7500 kg/hr for ~360 passengers (20.8 kg per hour per pax) and the A380 at 11,000 kg/hr for 519 seats (21.19 kg/hr per seat). Ok, not much differnce. But why?
1. A380 engines are same tech
2. Wing of A380 isn't optimal, a consequence of the 80m box (it really needs folding wingtips)
3. All the weight added for two decks that wasn't optimal.

So how to make an A380 much more efficient per passenger?
4. Stretch. Since there is a cost for two decks, there is a minimum economical size. In my opinion the A380 was too short. I am a fan of the Udvar-Hazy 85m length to 89m length. The choice of the 80m box was too short

In short, the above comparison is between a 16% stretched aircraft and an aircraft designed with a stretch in mind. It's mostly a confirmation that stretched aircraft are usually very efficient especially when equipped with the most advanced engine available (like the GE90-115). The lesson learned is that a potential VLA must aim from the start for an efficiency that puts it out of reach of the longest potential NEO-ed stretch of any existing widebody aircraft. That's quite a challenge actually.
 
patrickw421
Posts: 58
Joined: Sun Apr 23, 2017 6:49 pm

Re: Future VLA-aircraft

Sun Feb 21, 2021 4:26 pm

I think we will need a new solution for cargo space if another double-decker style VLA ever comes up. After loading luggage for 2 floors of passengers there is simply not so much space left for cargo in the current setting where cargo are only one layer in the belly.

The current pandemic also shows that strong belly cargo ability can help reduce the risk by turning it into a cargo plane when the pax operations is taking a big hit.

Part of the reason why 77W is so popular is the ability to take quite a lot of cargo on top of the pax operation and on the other hand if my memory is correct cathay pacific for example once commented that one of the reasons they aren't taking A380 is because they can't take a lot of cargo at the same time.
 
Armadillo1
Posts: 647
Joined: Thu Apr 20, 2017 5:14 pm

Re: Future VLA-aircraft

Sun Feb 21, 2021 4:47 pm

any current aircraft limited by wingspan.
so very big planes must address this somehow.
Avanti style looks more reasonable that other

others:

Image

also, i tried to start some discussion before:
viewtopic.php?t=1425107
 
User avatar
aemoreira1981
Posts: 3851
Joined: Mon Jan 09, 2017 12:17 am

Re: Future VLA-aircraft

Sun Feb 21, 2021 5:08 pm

I don't see a future for a VLA passenger frame. The B779, which will be at the B77W's MTOW of 351.5 metric tons, is likely the biggest one. The B779 would likely be a great cargo hauler in the belly as well. That basically leaves nonstandard cargo as what may need a VLA. The Boeing 787 has really right-sized the market, and on the passenger size, I would be surprised if the B78X doesn't become more popular among airlines who need the cargo capacity of a B772/B77L but not its range. For those needing capacity and more range, there would be the A35K (which is the exact length of the B77W). 300 passengers is the sweet spot in wide-body aviation.

I would have to wonder if Airbus was hoping that the A380 would be popular in China, but sales in China totaled just 5, and instead Chinese airlines loaded up on A330s. Also keep in mind that runways have to be strengthened to handle anything heavier than a Boeing 747. The B748 is VLA only because of wingspan. Regarding the A380, if it was made longer, you'd have too big a passenger plane to fill, in a world that demands frequency more than anything. So, one would need to envision a VLA as a cargo plane first.
 
ehaase
Posts: 153
Joined: Thu Jun 23, 2016 1:06 am

Re: Future VLA-aircraft

Sun Feb 21, 2021 6:15 pm

GalaxyFlyer wrote:
Has anyone here heard of flight shaming? Politics will kill massive tourism, which is what drives VLAs. Business travel, while profitable doesn’t require a VLA, but it’s numbers alone, except on very few routes. If anything we’ve reached peak airliner and will retreat to 787-A350 types for the next 30 years.

If this forum had a like button, I would click it for your post. With the politicians pushing climate change and explosive government, personal, and business debt, not to mention Covid, I am pessimistic about the economy and business, personal, and tourism travel for decades to come. I think the 777X will be a flop, and nothing larger than the 787-10 and 350-900 is needed.
 
frmrCapCadet
Posts: 4881
Joined: Thu May 29, 2008 8:24 pm

Re: Future VLA-aircraft

Sun Feb 21, 2021 8:25 pm

Next generation engines will make the 787/350 potent competitors for a next generation VLA.
Buffet: the airline business...has eaten up capital...like..no other (business)
 
User avatar
lightsaber
Moderator
Posts: 22386
Joined: Wed Jan 19, 2005 10:55 pm

Re: Future VLA-aircraft

Sun Feb 21, 2021 11:45 pm

Strato2 wrote:
lightsaber wrote:
That length meant the 77W carries a passenger for less fuel per trip than the A380! :wideeyed:

Here is a table of fuel burn per hour:
https://alliknowaviation.com/2019/12/14 ... -aircraft/

77W is 7500 kg/hr for ~360 passengers (20.8 kg per hour per pax) and the A380 at 11,000 kg/hr for 519 seats (21.19 kg/hr per seat). Ok, not much differnce. But why?

Lightsaber


Using your numbers and known cabin areas (A380 633m2, 300ER 338m2) gives a cabin area per pax of 1,219m2 for the A380 and 0,938 for the 300ER. The A380 has 30% more space per pax. An apples to golf balls comparison. With equal seating density you will have 674 seats on the A380 and per pax consumption of 16,32kg/hr per seat.

The A380 always will have more space per passenger as the layout needed to be so wide for cargo, but should have been wider for more seats, that was in the part not quoted.

The A380 also has more space that couldn't be utilized. E.g., why I went on about the staircases. I did as Apples to Apples a comparison as I could. Double decks have too much space that cannot be seats. That will always be the case, but Airbus was looking into new stairs to mitigate the issue. Alas, something that needed to be done early.

Seriously, current A338 with slimmer stairs ads room for 50 seats! (see link). Almost as bad as all the wasted potential crew rest space in the nose and tail. I see almost a meter of usable cabin length wasted in the nose and why are there not crew bunks above the front stairs and in the tail? I love the A380, but dang does Boeing pack in crew rests efficiently. Efficiency is always relative.

Link on planned improved staircase:
https://www.reuters.com/article/us-airb ... SKBN16F0YR

I agree space is there, just not for seat. When 40 to 50 seats of space is thrown away for a grand staircase, that is just hubris.

Lightsaber
7 months without TV. The best decision of my life.
 
Opus99
Posts: 2222
Joined: Thu May 30, 2019 10:51 pm

Re: Future VLA-aircraft

Sun Feb 21, 2021 11:51 pm

lightsaber wrote:
VLAs are en enigma. They work by carrying each passenger cheaper than smaller aircraft. Due to the ability to upgauge any airport (e.g., A319 to A321), they are not yet required.

The advantage of a VLA is that it can be very economical per passenger. My issue with the A380 is it was too small. Bear with me.
1. Stairways. These are required for a second deck, but take up substantial weight and space. This makes going from one deck to two inefficient initially. It takes a larger aircraft to "pay for the weight."
2. Elevators, fire systems, and plumbing on two decks also has a weight delta.
3. Initial large increase in surface area. This is an increase in drag.

The BWB sticks to one deck (in any viable concept I've seen), but has concerns on evacuation. I believe the evacuation problem has been solved. basically stairs analogous to the attic stairs to get to the top of the aircraft and then everyone walks off except for people near the front or back who have doors to use more typical slides.

What has to happen is far less surface area per passenger and less weight per passenger to get down costs. Now the A380 had incredibly great crew efficiency. e.g. a 787 and an A380 need the same quantity of pilots for the same flight. The same number of people to service the lavatories and same number of people to fuel or put water on the aircraft, just a little more time due to quantity. One must remember there are a lot of labor hours wasted in setup and disassembly instead of purely transferring the fluids. e.g., driving the truck to the aircraft (even if the truck is just carrying the people to do the job as all the equipment is in the aircraft pad. As an expert in fluids, my hat is off to the A380 plumbing engineers. :praise:

My conclusion is the A380 was too short. I would argue also just a fraction too narrow too. What?!? Yes, too small. When I look at the cross section, a tiny amount more weight and width gives 11 across main deck and 9 across top deck. They were too fixed on a market size instead of "what was the cost of a small increase?" Now as soon as that minor increase in width happens, a longer length is optimal. But also, the A380 lost too much space to stairways and other services to service the top deck. That length meant the 77W carries a passenger for less fuel per trip than the A380! :wideeyed:

Here is a table of fuel burn per hour:
https://alliknowaviation.com/2019/12/14 ... -aircraft/

77W is 7500 kg/hr for ~360 passengers (20.8 kg per hour per pax) and the A380 at 11,000 kg/hr for 519 seats (21.19 kg/hr per seat). Ok, not much differnce. But why?
1. A380 engines are same tech
2. Wing of A380 isn't optimal, a consequence of the 80m box (it really needs folding wingtips)
3. All the weight added for two decks that wasn't optimal.

So how to make an A380 much more efficient per passenger?
1. Get the cross section more optimal. A little more width gets 11 across bottom deck and 9 across top (in Y).
2. Optimize the stairways. Now this is 20/20 hindsight, but the cruise ship entry is lovely, but too costly for air travel. The rear stairs are bad.
3. Due to advances in 3D modeling tools, we could get better packaging of crew rests, In particular at the front and tail of the aircraft. Crew rests are needed. With modern CFRP bulkheads, so much space in that tail could be used today. More seats up near the front.
4. Stretch. Since there is a cost for two decks, there is a minimum economical size. In my opinion the A380 was too short. I am a fan of the Udvar-Hazy 85m length to 89m length. The choice of the 80m box was too short
5. More wing. Ok, first obviously it will be CFRP, but also we need folding wingtips. More than an 80m width is far too much real estate wasted at the gate. Too many airports are running out of real estate, so the gates much get more efficient.

I haven't looked into what the natural maximum wing span is. My opinion is that if 30+ of the large airports could accommodate an aircraft is sufficient. But there are certain airports required if any are to sell and that is: PEK & PKX, PVG, NRT, SIN, HKG, SYD, MEL, KG, LAX, JFK, LHR, CDG, FRA, DXB, BKK, and IST. I'm sorry if your favorite airport was listed, but the reality is, not every city must be served. J

For the business case of a VLA, not every major city must be served. Just enough. For example, India didn't allow the A380 at first, so unfortunately proved they are not part of the mandatory cities to service the type. The reality is one only has to service trunk routes between the USA, Europe, China, Japan, Thailand, and Australia as the minimum. Now ideally we add in South America, Africa, Indonesia, Malaysia, India, and secondary cities in the Emirates model (for example).

The BWB has merit and is a design that benefits from scale, but I have seen as little as 250 seat examples that would be competitive. The lack of a rudder forces 3 or 4 engines (one must design for the engine out condition which is over-powering in a twin), which will push the concept up in size very quickly. The BWB has better environmentalism, so I'm not sure on why that comment. It just needs to be big due to the constraints on the first examples.

So a double decker really doesn't work below 600 seats. :wideeyed:
A BWB works, but today I would say a minimum of 350 seats and if someone comes back and says 450, I would accept that (after they performed a detailed design study).

But for now, there just isn't enough demand. The 779, despite the incredibly advanced engines (a generation ahead of any other, in my opinion), is going to struggle. At this time we'll look at engine PiPs on the 787 and A350 as the main growth path (adding 777x engine technology back down to their engines, e.g., variable turbine cooling, CMC turbine inlet guide vanes, the more advanced low turbine, compressor blade shaping, but not the higher mach # compressors, better compressor and turbine matching between high and low spools, as those are not retrofittable, those features requiresa new engine architecture). I also *really* like Pratt's fan nozzle concept for reasons that are not yet public that I probably shouldn't discuss due to ancient NDAs (I used to work in Pratt's combustors, augmentors, and nozzles R&D group a long time ago).

We'll have VLAs, but it must be a larger VLA to gain per seat efficiency. The per seat efficiency must be so amazing that it is an easy win on trunk routes and that requires a large aircraft which limits the numbers sold.

Lightsaber

How good is the 779s per seat efficiency as a VLA?
 
User avatar
lightsaber
Moderator
Posts: 22386
Joined: Wed Jan 19, 2005 10:55 pm

Re: Future VLA-aircraft

Mon Feb 22, 2021 3:13 am

Opus99 wrote:
lightsaber wrote:
VLAs are en enigma. They work by carrying each passenger cheaper than smaller aircraft. Due to the ability to upgauge any airport (e.g., A319 to A321), they are not yet required.

The advantage of a VLA is that it can be very economical per passenger. My issue with the A380 is it was too small. Bear with me.
1. Stairways. These are required for a second deck, but take up substantial weight and space. This makes going from one deck to two inefficient initially. It takes a larger aircraft to "pay for the weight."
2. Elevators, fire systems, and plumbing on two decks also has a weight delta.
3. Initial large increase in surface area. This is an increase in drag.

The BWB sticks to one deck (in any viable concept I've seen), but has concerns on evacuation. I believe the evacuation problem has been solved. basically stairs analogous to the attic stairs to get to the top of the aircraft and then everyone walks off except for people near the front or back who have doors to use more typical slides.

What has to happen is far less surface area per passenger and less weight per passenger to get down costs. Now the A380 had incredibly great crew efficiency. e.g. a 787 and an A380 need the same quantity of pilots for the same flight. The same number of people to service the lavatories and same number of people to fuel or put water on the aircraft, just a little more time due to quantity. One must remember there are a lot of labor hours wasted in setup and disassembly instead of purely transferring the fluids. e.g., driving the truck to the aircraft (even if the truck is just carrying the people to do the job as all the equipment is in the aircraft pad. As an expert in fluids, my hat is off to the A380 plumbing engineers. :praise:

My conclusion is the A380 was too short. I would argue also just a fraction too narrow too. What?!? Yes, too small. When I look at the cross section, a tiny amount more weight and width gives 11 across main deck and 9 across top deck. They were too fixed on a market size instead of "what was the cost of a small increase?" Now as soon as that minor increase in width happens, a longer length is optimal. But also, the A380 lost too much space to stairways and other services to service the top deck. That length meant the 77W carries a passenger for less fuel per trip than the A380! :wideeyed:

Here is a table of fuel burn per hour:
https://alliknowaviation.com/2019/12/14 ... -aircraft/

77W is 7500 kg/hr for ~360 passengers (20.8 kg per hour per pax) and the A380 at 11,000 kg/hr for 519 seats (21.19 kg/hr per seat). Ok, not much differnce. But why?
1. A380 engines are same tech
2. Wing of A380 isn't optimal, a consequence of the 80m box (it really needs folding wingtips)
3. All the weight added for two decks that wasn't optimal.

So how to make an A380 much more efficient per passenger?
1. Get the cross section more optimal. A little more width gets 11 across bottom deck and 9 across top (in Y).
2. Optimize the stairways. Now this is 20/20 hindsight, but the cruise ship entry is lovely, but too costly for air travel. The rear stairs are bad.
3. Due to advances in 3D modeling tools, we could get better packaging of crew rests, In particular at the front and tail of the aircraft. Crew rests are needed. With modern CFRP bulkheads, so much space in that tail could be used today. More seats up near the front.
4. Stretch. Since there is a cost for two decks, there is a minimum economical size. In my opinion the A380 was too short. I am a fan of the Udvar-Hazy 85m length to 89m length. The choice of the 80m box was too short
5. More wing. Ok, first obviously it will be CFRP, but also we need folding wingtips. More than an 80m width is far too much real estate wasted at the gate. Too many airports are running out of real estate, so the gates much get more efficient.

I haven't looked into what the natural maximum wing span is. My opinion is that if 30+ of the large airports could accommodate an aircraft is sufficient. But there are certain airports required if any are to sell and that is: PEK & PKX, PVG, NRT, SIN, HKG, SYD, MEL, KG, LAX, JFK, LHR, CDG, FRA, DXB, BKK, and IST. I'm sorry if your favorite airport was listed, but the reality is, not every city must be served. J

For the business case of a VLA, not every major city must be served. Just enough. For example, India didn't allow the A380 at first, so unfortunately proved they are not part of the mandatory cities to service the type. The reality is one only has to service trunk routes between the USA, Europe, China, Japan, Thailand, and Australia as the minimum. Now ideally we add in South America, Africa, Indonesia, Malaysia, India, and secondary cities in the Emirates model (for example).

The BWB has merit and is a design that benefits from scale, but I have seen as little as 250 seat examples that would be competitive. The lack of a rudder forces 3 or 4 engines (one must design for the engine out condition which is over-powering in a twin), which will push the concept up in size very quickly. The BWB has better environmentalism, so I'm not sure on why that comment. It just needs to be big due to the constraints on the first examples.

So a double decker really doesn't work below 600 seats. :wideeyed:
A BWB works, but today I would say a minimum of 350 seats and if someone comes back and says 450, I would accept that (after they performed a detailed design study).

But for now, there just isn't enough demand. The 779, despite the incredibly advanced engines (a generation ahead of any other, in my opinion), is going to struggle. At this time we'll look at engine PiPs on the 787 and A350 as the main growth path (adding 777x engine technology back down to their engines, e.g., variable turbine cooling, CMC turbine inlet guide vanes, the more advanced low turbine, compressor blade shaping, but not the higher mach # compressors, better compressor and turbine matching between high and low spools, as those are not retrofittable, those features requiresa new engine architecture). I also *really* like Pratt's fan nozzle concept for reasons that are not yet public that I probably shouldn't discuss due to ancient NDAs (I used to work in Pratt's combustors, augmentors, and nozzles R&D group a long time ago).

We'll have VLAs, but it must be a larger VLA to gain per seat efficiency. The per seat efficiency must be so amazing that it is an easy win on trunk routes and that requires a large aircraft which limits the numbers sold.

Lightsaber

How good is the 779s per seat efficiency as a VLA?

I need flight test data. Certain numbers aren't adding up. Worst cast 420 seats for the fuel of 360 or 17.8 kg/hr/pax. However, with the everything thrown at it, new wing, and next generation engines, it should be lower. Much lower. But how much? My best case estimate is ~16 kg/hr/pax in 3 class density.

I am waiting on data. It looks like I have a while to wait. If you want A350/787, it gets contentious:
viewtopic.php?t=1403667

Lightsaber
7 months without TV. The best decision of my life.
 
cynlb
Posts: 111
Joined: Sat Jan 27, 2018 3:49 pm

Re: Future VLA-aircraft

Mon Feb 22, 2021 4:16 am

I think a spiral staircase, like in the early 747-100/-200s, could have taken up less space and probably a lot less weight than the a380 stairways. Just a thought


lightsaber wrote:
VLAs are en enigma. They work by carrying each passenger cheaper than smaller aircraft. Due to the ability to upgauge any airport (e.g., A319 to A321), they are not yet required.

The advantage of a VLA is that it can be very economical per passenger. My issue with the A380 is it was too small. Bear with me.
1. Stairways. These are required for a second deck, but take up substantial weight and space. This makes going from one deck to two inefficient initially. It takes a larger aircraft to "pay for the weight."
2. Elevators, fire systems, and plumbing on two decks also has a weight delta.
3. Initial large increase in surface area. This is an increase in drag.

The BWB sticks to one deck (in any viable concept I've seen), but has concerns on evacuation. I believe the evacuation problem has been solved. basically stairs analogous to the attic stairs to get to the top of the aircraft and then everyone walks off except for people near the front or back who have doors to use more typical slides.

What has to happen is far less surface area per passenger and less weight per passenger to get down costs. Now the A380 had incredibly great crew efficiency. e.g. a 787 and an A380 need the same quantity of pilots for the same flight. The same number of people to service the lavatories and same number of people to fuel or put water on the aircraft, just a little more time due to quantity. One must remember there are a lot of labor hours wasted in setup and disassembly instead of purely transferring the fluids. e.g., driving the truck to the aircraft (even if the truck is just carrying the people to do the job as all the equipment is in the aircraft pad. As an expert in fluids, my hat is off to the A380 plumbing engineers. :praise:

My conclusion is the A380 was too short. I would argue also just a fraction too narrow too. What?!? Yes, too small. When I look at the cross section, a tiny amount more weight and width gives 11 across main deck and 9 across top deck. They were too fixed on a market size instead of "what was the cost of a small increase?" Now as soon as that minor increase in width happens, a longer length is optimal. But also, the A380 lost too much space to stairways and other services to service the top deck. That length meant the 77W carries a passenger for less fuel per trip than the A380! :wideeyed:

Here is a table of fuel burn per hour:
https://alliknowaviation.com/2019/12/14 ... -aircraft/

77W is 7500 kg/hr for ~360 passengers (20.8 kg per hour per pax) and the A380 at 11,000 kg/hr for 519 seats (21.19 kg/hr per seat). Ok, not much differnce. But why?
1. A380 engines are same tech
2. Wing of A380 isn't optimal, a consequence of the 80m box (it really needs folding wingtips)
3. All the weight added for two decks that wasn't optimal.

So how to make an A380 much more efficient per passenger?
1. Get the cross section more optimal. A little more width gets 11 across bottom deck and 9 across top (in Y).
2. Optimize the stairways. Now this is 20/20 hindsight, but the cruise ship entry is lovely, but too costly for air travel. The rear stairs are bad.
3. Due to advances in 3D modeling tools, we could get better packaging of crew rests, In particular at the front and tail of the aircraft. Crew rests are needed. With modern CFRP bulkheads, so much space in that tail could be used today. More seats up near the front.
4. Stretch. Since there is a cost for two decks, there is a minimum economical size. In my opinion the A380 was too short. I am a fan of the Udvar-Hazy 85m length to 89m length. The choice of the 80m box was too short
5. More wing. Ok, first obviously it will be CFRP, but also we need folding wingtips. More than an 80m width is far too much real estate wasted at the gate. Too many airports are running out of real estate, so the gates much get more efficient.

I haven't looked into what the natural maximum wing span is. My opinion is that if 30+ of the large airports could accommodate an aircraft is sufficient. But there are certain airports required if any are to sell and that is: PEK & PKX, PVG, NRT, SIN, HKG, SYD, MEL, KG, LAX, JFK, LHR, CDG, FRA, DXB, BKK, and IST. I'm sorry if your favorite airport was listed, but the reality is, not every city must be served. J

For the business case of a VLA, not every major city must be served. Just enough. For example, India didn't allow the A380 at first, so unfortunately proved they are not part of the mandatory cities to service the type. The reality is one only has to service trunk routes between the USA, Europe, China, Japan, Thailand, and Australia as the minimum. Now ideally we add in South America, Africa, Indonesia, Malaysia, India, and secondary cities in the Emirates model (for example).

The BWB has merit and is a design that benefits from scale, but I have seen as little as 250 seat examples that would be competitive. The lack of a rudder forces 3 or 4 engines (one must design for the engine out condition which is over-powering in a twin), which will push the concept up in size very quickly. The BWB has better environmentalism, so I'm not sure on why that comment. It just needs to be big due to the constraints on the first examples.

So a double decker really doesn't work below 600 seats. :wideeyed:
A BWB works, but today I would say a minimum of 350 seats and if someone comes back and says 450, I would accept that (after they performed a detailed design study).

But for now, there just isn't enough demand. The 779, despite the incredibly advanced engines (a generation ahead of any other, in my opinion), is going to struggle. At this time we'll look at engine PiPs on the 787 and A350 as the main growth path (adding 777x engine technology back down to their engines, e.g., variable turbine cooling, CMC turbine inlet guide vanes, the more advanced low turbine, compressor blade shaping, but not the higher mach # compressors, better compressor and turbine matching between high and low spools, as those are not retrofittable, those features requiresa new engine architecture). I also *really* like Pratt's fan nozzle concept for reasons that are not yet public that I probably shouldn't discuss due to ancient NDAs (I used to work in Pratt's combustors, augmentors, and nozzles R&D group a long time ago).

We'll have VLAs, but it must be a larger VLA to gain per seat efficiency. The per seat efficiency must be so amazing that it is an easy win on trunk routes and that requires a large aircraft which limits the numbers sold.

Lightsaber
 
User avatar
DLHAM
Posts: 633
Joined: Sat Dec 31, 2016 1:10 am

Re: Future VLA-aircraft

Mon Feb 22, 2021 4:42 am

I think that the 777-9 is the perfect VLA (well, if you consider it a VLA). Also I think that the 777-9 will be the largest aircraft available for a very long time. It may be a bit smaller than an A380 but its so much more efficient -- the step up in size and capacity to make a larger airplane (which has to be Double Deck to fit all passengers) at the same Level of efficiency is pretty big.
Also we learned that many Airlines prefer frequency over capacity. Means that an airplane much larger than the 777-9 just may be too large for most Airlines.
My Instagram Account: Instagram
 
flyinggoat
Posts: 343
Joined: Fri Apr 19, 2013 2:38 am

Re: Future VLA-aircraft

Mon Feb 22, 2021 5:05 am

Personally, I think the 787 and A350 will fill the majority of the VLA role for now, with the 777-9 coming in at the top end.

When the 777-9 gets replaced, I suspect we will see another 10 abreast aircraft with a slightly wider fuselage. If an aircraft larger than that is needed, and if Boeing (or Airbus) perfect the ovoid fuselage, than perhaps we will see a three aisle 12 or 14 abreast aircraft, possibly with a cargo hold wide enough for three rows of containers.

Just my $.02.
 
marcelh
Posts: 1428
Joined: Wed Jun 19, 2013 12:43 pm

Re: Future VLA-aircraft

Mon Feb 22, 2021 6:04 am

DLHAM wrote:
I think that the 777-9 is the perfect VLA (well, if you consider it a VLA). Also I think that the 777-9 will be the largest aircraft available for a very long time. It may be a bit smaller than an A380 but its so much more efficient -- the step up in size and capacity to make a larger airplane (which has to be Double Deck to fit all passengers) at the same Level of efficiency is pretty big.
Also we learned that many Airlines prefer frequency over capacity. Means that an airplane much larger than the 777-9 just may be too large for most Airlines.

Preferring frequency over capacity is (was?) mainly driven by business related passengers. We have learned that video conferencing is going to stay. We will have to see what is going to happen. Less business related traveling will have impact on air travel.
 
JayinKitsap
Posts: 2508
Joined: Sat Nov 26, 2005 9:55 am

Re: Future VLA-aircraft

Mon Feb 22, 2021 7:37 am

DLHAM wrote:
I think that the 777-9 is the perfect VLA (well, if you consider it a VLA). Also I think that the 777-9 will be the largest aircraft available for a very long time. It may be a bit smaller than an A380 but its so much more efficient -- the step up in size and capacity to make a larger airplane (which has to be Double Deck to fit all passengers) at the same Level of efficiency is pretty big.
Also we learned that many Airlines prefer frequency over capacity. Means that an airplane much larger than the 777-9 just may be too large for most Airlines.


I agree that the 777-9 will be the largest available for a very long time, some added reasons.

1) For length the 777-9 is 251 ft 9 in (76.7 m), getting quite close to the 80 m box for length. Going beyond the 80 m would play total havoc with airport planning. Going to 90 meters with gates on both sides of the taxiway means the total width suddenly grows for 240 m to 270 m.

1A) On length any longer than the 777-9 would further reduce the angle available for rotation, seriously messing with the takeoff performance.

2) For width, the 779 is 235 ft 5 in (71.75 m), 212 ft 9 in (64.85 m) folded. A future plane can go to 80 m with folding wings of up to 65m. As the bending moment of the wing is a square function anything longer will greatly increase the wing structure. Longer than the 71.75m will not be as efficient as the OEW would rise.

3) For wheel loading of the runway the 777 has a MTOW of 775,000 lb / 351,533 kg carried by two 6 wheel gear. It's load per gear is quite high for pavement loading, any higher would require a 3rd set of MLG on the hull CL.

4) Engines - the current GE9X has a 132 in (335 cm) fan while the width of the cabin is 231 in / 5.86 m. Shipping a spare engine on any airplane requires the fan to be removed from the core, at some point a wider fan will become difficult to ship.

5) Engines - going to a larger diameter raises the tip speed for a given RPM, can't go supersonic efficiently. Raising the thrust would be a very expensive overtaking to develop, it has to be able to take off on 1 engine.

6) Hull diameter - going to 12 across ( 3-6-3) adds a lot of middle seats while increasing the capacity per row by 9%, beyond 12 requires an additional aisle. In this diameter, circular is the only way to go for efficiency, for compression buckling external load cases would require a good bit more structure. Going larger increases the frontal area with little benefit for the customer. The crown area would be difficult to use for any functional purpose.

7) Range - is basically solved. The 779 has all the practical range it needs. Extra long haul has a far lower demand so the VLA really cannot use added range and the routes needing added range are best served by smaller planes.

8) Insurance cost - Rises with the size and it is substantial cost.

9) Takeoff and Landing fees- As it is very close to the pavement limits, pavement maintenance is a big cost and the fees would be quite high to cover this added cost.

10) Frequency vs capacity. it is quite true that the AVERAGE plane size needs to increase to handle growing volume, but as over 80% of all flights are in NB territory, increasing the WB fleet capacity does little to increase the AVERAGE plane size.

Efficiency is so important with a plan, the smallest plane that can do the route need only match the efficiency of the VLA. All of the above factors tend to reduce the efficiency of the plane. ===>>> Bigger than the 779 would not pencil out the investment to develop, thus no authority to offer.
 
WIederling
Posts: 10043
Joined: Sun Sep 13, 2015 2:15 pm

Re: Future VLA-aircraft

Mon Feb 22, 2021 9:33 am

"A380 too small"

Issue for Airbus was that the abyss between single deck and double decker is much larger than between Single and Double Aisle ( "MOM" country, where no sane designer will go :-)

LH back then made it known they would buy a 1000 seater A380.
One other issue that makes smalish airplane sales numbers look good:

Demand is not planes but seats.
Sell ONE 1kseats plane
vs
sell TEN 100pax planes

and I'd like to add my CATO quip:
P2P is a dumb idea except for some outlier connections.

Best of breed is the 2Hub connected by Addidas/Puma network model.( Emirates )
every P2H connection can contribute to any other H2P connection (other lobe ( or same )
Murphy is an optimist
 
Misterven1
Topic Author
Posts: 23
Joined: Sun May 20, 2018 7:30 pm

Re: Future VLA-aircraft

Mon Feb 22, 2021 7:43 pm

https://ibb.co/gF2zG8w
An example mini-VLA airliner of 300 to 450 passengers derived from Boeing 767, supplemented with top deck. This plane is much smaller than Airbus A380. The lower deck has 8 seats in a row and the upper deck has only 6 seats, but with 2 aisles. There are also many options from the top deck with Business Class 1-1-1 per row and Economy Premium 1-2-1. And on the lower deck you can do 2-2-2 in a row for Business Class and 2-3-2 in Economy Premium. He would fly quite a distance of 14,000-16,000 km.

In itself, a mini-VLA aircraft would be much cheaper and more efficient than a very large VLA aircraft. Why did the aircraft builders never think of such a concept where they can also build a small double-deck plane instead of a very large plane?

Because if you only continue to work with very large aircraft, it is never good, but you should also look at slightly smaller aircraft, which can also be used more profitably
 
WIederling
Posts: 10043
Joined: Sun Sep 13, 2015 2:15 pm

Re: Future VLA-aircraft

Mon Feb 22, 2021 9:03 pm

Misterven1 wrote:
https://ibb.co/gF2zG8w
An example mini-VLA airliner of 300 to 450 passengers derived from Boeing 767, supplemented with top deck. This plane is much smaller than Airbus A380. The lower deck has 8 seats in a row and the upper deck has only 6 seats, but with 2 aisles.


Guess why it was never done!
Murphy is an optimist
 
Misterven1
Topic Author
Posts: 23
Joined: Sun May 20, 2018 7:30 pm

Re: Future VLA-aircraft

Tue Feb 23, 2021 1:25 pm

WIederling wrote:
Misterven1 wrote:
https://ibb.co/gF2zG8w
An example mini-VLA airliner of 300 to 450 passengers derived from Boeing 767, supplemented with top deck. This plane is much smaller than Airbus A380. The lower deck has 8 seats in a row and the upper deck has only 6 seats, but with 2 aisles.


Guess why it was never done!

Well, I can also guess that there is not enough market for this, but it is certain that we have never heard of smaller VLA aircraft before. The concept I drew is an example of how it can become reality in the future.

It is not yet very innovative in terms of developments for a new aircraft, but never write off the VLA because we never know how aviation will recover from a corona pandemic.

If the aviation world starts to recover so fast after the corona pandemic, there will be new orders for various aircraft from Airbus or Boeing. Then the discussion about a future VLA plane comes back of itself if it should be large or small. I think that in the future there will be a market for small, medium and very large double-decker aircraft, both this is also much space-saving for various airports.

If one wants to develop a larger aircraft than Boeing 777-9X, the question is also whether that very large and long aircraft will be handled safely at the airport. but the question also arises whether a very large and long aircraft will require a longer runway. A longer and larger plane is not really effective especially when getting in and out of the passengers. but also costs too much in turnaround times. I think many airlines would prefer not to have very long and large aircraft in their fleets, even emergency safety is a problem for the FAA.

The requirements of the FAA are strict, such as procedures for exiting the aircraft in an emergency. The passengers must be able to quickly leave the burning or crashed long and very large plane in 90-100 seconds via a slide. But it is also important to carefully consider the numbers of passengers who can safely fly very long and large aircraft. Per aircraft is always corrected with safety aspects and the number of permitted number of passengers per flight. The FAA would never allow more than 500 passengers to board a Boeing 777-9X, despite having 5 ships installed on each side of the fuselage.
 
User avatar
AirKevin
Posts: 749
Joined: Wed Apr 26, 2017 2:18 am

Re: Future VLA-aircraft

Tue Feb 23, 2021 3:39 pm

Misterven1 wrote:
The passengers must be able to quickly leave the burning or crashed long and very large plane in 90-100 seconds via a slide.

The certification requirement is for the passengers to be evacuated in 90 seconds or less with half of the usable exits available.
Captain Kevin
 
User avatar
NameOmitted
Posts: 1026
Joined: Sun Oct 23, 2016 7:59 pm

Re: Future VLA-aircraft

Tue Feb 23, 2021 3:53 pm

The issue with predicting the next VLA is the amount of time between here and there. If Boeing shows the possibility of an oval, might we see a 3-4-4-3 or 3-5-5-3 cross-section?

A lot can happen in 25 years. A second floor might not be needed for an aircraft to get a lot larger than the 777X
 
User avatar
william
Posts: 3454
Joined: Thu Jun 10, 1999 1:31 pm

Re: Future VLA-aircraft

Tue Feb 23, 2021 4:18 pm

RJMAZ had an interesting proposal a couple of years ago for a VLA based on the 777X platform. It was a 777 with a 747 hump on it. For some reason the picture will not post.

viewtopic.php?f=3&t=1383997&p=20100425&hilit=777+with+hump#p20100425
 
User avatar
william
Posts: 3454
Joined: Thu Jun 10, 1999 1:31 pm

Re: Future VLA-aircraft

Tue Feb 23, 2021 4:21 pm

Keejse's Ecoliner concept was 14 years ago (dang I am getting old).

viewtopic.php?f=3&t=474581&hilit=ecoliner+keejse

Its probably similar to what the OP's idea of a next gen VLA.
 
ILNFlyer
Posts: 674
Joined: Wed Jun 15, 2016 8:34 pm

Re: Future VLA-aircraft

Tue Feb 23, 2021 4:50 pm

DLHAM wrote:
I think that the 777-9 is the perfect VLA (well, if you consider it a VLA). Also I think that the 777-9 will be the largest aircraft available for a very long time. It may be a bit smaller than an A380 but its so much more efficient -- the step up in size and capacity to make a larger airplane (which has to be Double Deck to fit all passengers) at the same Level of efficiency is pretty big.
Also we learned that many Airlines prefer frequency over capacity. Means that an airplane much larger than the 777-9 just may be too large for most Airlines.


Agreed. Fits the role rather well once the pax numbers recover. I'm afraid to say the next one might be a twin engine 600 pax aircraft with even more massive engines.
 
User avatar
VirginFlyer
Posts: 5700
Joined: Sun Sep 10, 2000 12:27 pm

Re: Future VLA-aircraft

Tue Feb 23, 2021 5:06 pm

william wrote:
RJMAZ had an interesting proposal a couple of years ago for a VLA based on the 777X platform. It was a 777 with a 747 hump on it. For some reason the picture will not post.

viewtopic.php?f=3&t=1383997&p=20100425&hilit=777+with+hump#p20100425

It looks like embedding the picture isn’t permitted, but the links still work: http://members.iinet.net.au/~1300subbox/777x10.jpg
http://members.iinet.net.au/~1300subbox ... 0cross.jpg

Also for ease of reading, here’s the thread without the highlighting and from the opening post: viewtopic.php?f=3&t=1383997

I think if going for such a solution, you might as well shift the flight deck to the upper deck to enable a nose-door freight option as pointed out in that thread (although whether the 747-style zone A would still be permitted in passenger configuration is something I gather is an issue: it might require an emergency exit right at the front). Of course, all the signs would indicate it is doubtful an aircraft larger than the 777-9 is needed any time soon, so by the time it is I suspect that the 777-9 will be an older platform, and it would make more sense to go clean sheet.

V/F
It is not for him to pride himself who loveth his own country, but rather for him who loveth the whole world. The earth is but one country, and mankind its citizens. —Bahá'u'lláh
 
Misterven1
Topic Author
Posts: 23
Joined: Sun May 20, 2018 7:30 pm

Re: Future VLA-aircraft

Tue Feb 23, 2021 5:20 pm

AirKevin wrote:
Misterven1 wrote:
The passengers must be able to quickly leave the burning or crashed long and very large plane in 90-100 seconds via a slide.

The certification requirement is for the passengers to be evacuated in 90 seconds or less with half of the usable exits available.


Yes that's what I mean. But with a very large and long VLA aircraft, it is much more difficult to evacuate the passengers in 90 seconds or less, especially in an emergency landing or fire on the aircraft. .
 
MikeChin
Posts: 5
Joined: Fri Mar 09, 2018 9:35 pm

Re: Future VLA-aircraft

Tue Feb 23, 2021 6:06 pm

the thing about future post-COVID growth, is that not all growth happens on the same area-routes. Meaning, that current "busy" routes that are serve by current widebodies, might not be the ones that continue to growth exponentially, but in most cases, is new routes and countries that enter rapid phases of development, but these to can be served by airplanes roughtly the same size of current widebodies.

And technology on engines, means that range is no longer associated with airplane size.

Going forward, I think that even thought the average seat count per plane will continue to rise, but mostly because of the incremental upgrades we have been looking on the new versions of current narrow bodies. Not long ago, most 737's and 320's, had seating capacity in the 110-150 range, and newer MAX and NEO versions, can pack closer to 200. On the other hand, most airlines have concluded that with current traffic patterns, and existing infrastructure, a wide body plane of around 300-350 seats, its the sweet spot on a cost-benefit analysis.

But something else to factor in, is the ever increasing growth of web sales, that in turn, increase the demand of shipping. If most of the world becomes Amazon territory or any local equivalent, the demand of express shipping will go thru the roof, and maybe the cargo market will change if ways we cannot visualize right now.
 
rbavfan
Posts: 3807
Joined: Fri Apr 17, 2015 5:53 am

Re: Future VLA-aircraft

Tue Feb 23, 2021 7:46 pm

The 777-9 seats the same range as the original 747-100 and has a greater wing span we cannot really say VLA aircraft are going away It is the new VLA.
.
 
Vladex
Posts: 544
Joined: Sat Oct 26, 2013 2:44 pm

Re: Future VLA-aircraft

Wed Feb 24, 2021 1:35 am

The two trends of engine developments and electrification clearly show that the larger aircraft is the more efficient and has more range . Next year RR Ultra fan is being put on ice because they have nowhere to put it as it's too big for 350/787 . I did some rudimentary calculations for battery density of 500 w/kg which will become realistic by 2030 and it shows that the wide bodies have more than twice the range with current A380 at around 1500 nm and A350-1000 at 1640 nm while A321neo is only 720nm and A220 at 700nm , As an outsider , I am baffled at the logic of foregoing the simple logic of near future and putting everything into something that is limited and short term.
 
User avatar
CarlosSi
Posts: 741
Joined: Sat Jul 08, 2017 8:29 pm

Re: Future VLA-aircraft

Wed Feb 24, 2021 2:43 am

The only real case for anything bigger than the 77X now is if such a route is already overbooked, and the frequency is hourly 7 to 7 daily. Theoretically you could even have two planes at the airport both preparing to leave (actually I've seen a couple of arrivals DFW-AUS here back to back, albeit probably from delays!) at the same time, but at that point it's probably congested that you have other problems.

3-5-3 is probably the best you can do, but you better have really good exit access to satisfy the exit limit.

Certainly, narrowbodies have and will displace widebodies on certain routes, and they're just getting started, although if we're talking VLA, then we're also talking about airports with the most capacity, and they're going to be slot-controlled.
 
Vladex
Posts: 544
Joined: Sat Oct 26, 2013 2:44 pm

Re: Future VLA-aircraft

Wed Feb 24, 2021 7:11 pm

CarlosSi wrote:
The only real case for anything bigger than the 77X now is if such a route is already overbooked, and the frequency is hourly 7 to 7 daily. Theoretically you could even have two planes at the airport both preparing to leave (actually I've seen a couple of arrivals DFW-AUS here back to back, albeit probably from delays!) at the same time, but at that point it's probably congested that you have other problems.

3-5-3 is probably the best you can do, but you better have really good exit access to satisfy the exit limit.

Certainly, narrowbodies have and will displace widebodies on certain routes, and they're just getting started, although if we're talking VLA, then we're also talking about airports with the most capacity, and they're going to be slot-controlled.


That was all true 20 years ago and still A380 and even 747-8 happened and now it's even more skewed toward bigger planes. Prior to Covid shutdown, most hubs were already fully congested, new engines are getting more efficient and bigger such as the RR Ultrafan which is now frozen as it's too big for the current models and finally I project that electrification will come in aviation as well and it also favors bigger models. as opposed to narrowbodies especially.
 
slider
Posts: 7735
Joined: Wed Feb 25, 2004 11:42 pm

Re: Future VLA-aircraft

Wed Feb 24, 2021 7:30 pm

In a post-Covid world, I'm of the opinion that any future VLA will not be necessary for a few decades, at best.

Popular Searches On Airliners.net

Top Photos of Last:   24 Hours  •  48 Hours  •  7 Days  •  30 Days  •  180 Days  •  365 Days  •  All Time

Military Aircraft Every type from fighters to helicopters from air forces around the globe

Classic Airliners Props and jets from the good old days

Flight Decks Views from inside the cockpit

Aircraft Cabins Passenger cabin shots showing seat arrangements as well as cargo aircraft interior

Cargo Aircraft Pictures of great freighter aircraft

Government Aircraft Aircraft flying government officials

Helicopters Our large helicopter section. Both military and civil versions

Blimps / Airships Everything from the Goodyear blimp to the Zeppelin

Night Photos Beautiful shots taken while the sun is below the horizon

Accidents Accident, incident and crash related photos

Air to Air Photos taken by airborne photographers of airborne aircraft

Special Paint Schemes Aircraft painted in beautiful and original liveries

Airport Overviews Airport overviews from the air or ground

Tails and Winglets Tail and Winglet closeups with beautiful airline logos