What if

Hot Research Topics => Aircraft, Armor, Weapons and Ships by Topic => Topic started by: steelpillow on April 14, 2015, 05:15:56 am

Title: Giant aeroplanes
Post by: steelpillow on April 14, 2015, 05:15:56 am
Apologies if this is not a new topic.
Some recent posts set me thinking, what is a practical shape for a giant aeroplane? Some of the design constraints, e.g. on the Airbus A380, are:

It is sometimes said that the flying wing airliner only makes sense on a huge scale. Some concept designs show a delta-shaped inner wing blending into slender swept outer sections. Engines typically mounted above the trailing edge. This is actually a rubbish idea that would never be approved because:

Some improvements could be made by moving the engines back to the traditional hanging leading-edge pods. This would allow upper trailing-edge exit doors to operate by dropping down onto the floor to open. But passengers at the front of the delta would still be too far away, so that has to be abandoned and a more traditional swept wing of greater span used. A smooth cranking of the wing to give outboard dihedral would shorten the otherwise extra-long undercarriage while raising the tips clear of the ground at takeoff. This is opposite of the A380's gulled wing - one might even have an S-dihedral, with the intermediate section of each wing having reduced dihedral. But the big problem remains, how to accommodate such a huge wing span?

Another approach would be to take the A380 a few steps further. It is designed for a stretched fuselage length, that's easy. But the fuselage width is limited b the need to avoid a deep auditorium-style room space, it is already taller than it can be made wide. A third deck would be a heavy, inefficient answer on such a fixed width. Better to add another fuselage or two. With the wing root chord and span already at the limits, some increase in the mid-section chord would help, also a lifting tail using relaxed static stability, a new foreplane so that the wing can be used more efficiently and possibly even a second wing in tandem, all beginning to look very like a Burt Rutan design on steroids.

So may I present a couple of concept whiffs:

Permanent soaring city A giant flying wing, this craft has no engines, but soars in the updraft found along Southern mountain ranges such as found in South America and New Zealand. It has an almost indefinite span, being on this scale flexible rather like some of the experimental ultra-lightweight solar aircraft. One can fly a new wing section up to it, bolt it on and then remove the ferry power unit.

Mega-liner Triple-hulled, tandem-winged four-surface airliner. 3,000 passengers, Six engines of near-double-Trent class. Fits within the 80m x 80m handling box of current major airports.
Title: Re: Giant aeroplanes
Post by: Hobbes on April 14, 2015, 05:55:02 am
Like this?

(http://i9.photobucket.com/albums/a94/WtMiller/scan0019.jpg)

(from http://www.whatifmodelers.com/index.php/topic,7853.0.html (http://www.whatifmodelers.com/index.php/topic,7853.0.html))

That's a real-world proposal for a 3-fuselage VC-10  :blink:
Title: Re: Giant aeroplanes
Post by: steelpillow on April 14, 2015, 08:23:28 am
:) Getting there. Note enough wings, not enough engines, not enough bigness yet.
Title: Re: Giant aeroplanes
Post by: PR19_Kit on April 14, 2015, 09:18:11 am
 ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D

(http://img537.imageshack.us/img537/9682/NlmYC4.jpg)
Title: Re: Giant aeroplanes
Post by: ericr on April 14, 2015, 10:57:44 am
;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D

(http://img537.imageshack.us/img537/9682/NlmYC4.jpg)

strange : this time it's not quite the wingspan that got larger  :unsure:  :rolleyes:
Title: Re: Giant aeroplanes
Post by: PR19_Kit on April 14, 2015, 11:23:15 am

strange : this time it's not quite the wingspan that got larger  :unsure:  :rolleyes:


Oh, but it did, albeit not by much.

I added some stainless steel -300 tips I found on ebay. That's AFTER I'd tested about 5-6 glues to see what would stick them to the styrene!  :o
Title: Re: Giant aeroplanes
Post by: pyro-manic on April 14, 2015, 04:50:20 pm
How about a passenger carrying variant of the Stratolaunch/Rutan Roc? Passenger pod instead of the rocket, and cabins in the fuselages as well. Not at all practical, but would be impressive. ;D

(http://airpigz.com/storage/2011-december/Stratolaunch-System.jpg?__SQUARESPACE_CACHEVERSION=1323867026840)
Title: Re: Giant aeroplanes
Post by: rickshaw on April 14, 2015, 05:31:33 pm
Personally, I believe that giant, steam-powered airships offer the best solution to all your problems!  ;) ;D ;D

(http://i773.photobucket.com/albums/yy19/DarkZerkerX/UlvenaAirshipEHSVirgo.jpg)
Title: Re: Giant aeroplanes
Post by: pyro-manic on April 14, 2015, 05:54:19 pm
Well obviously, but the thread is "Giant Aeroplanes". :P ;D
Title: Re: Giant aeroplanes
Post by: kitnut617 on April 14, 2015, 07:04:25 pm
Lockheed did investigate this set-up, the model was displayed in their front foyer for a long time.

 (http://i200.photobucket.com/albums/aa263/kitnut617/Misc%20Photos/TwinC5.jpg) (http://s200.photobucket.com/user/kitnut617/media/Misc%20Photos/TwinC5.jpg.html)

Title: Re: Giant aeroplanes
Post by: Captain Canada on April 14, 2015, 07:22:18 pm
Love the triple....imagine seeing ( and hearing ! ) that take off ?

 :wub:
Title: Re: Giant aeroplanes
Post by: KiwiZac on April 14, 2015, 07:30:29 pm
Permanent soaring city A giant flying wing, this craft has no engines, but soars in the updraft found along Southern mountain ranges such as found in South America and New Zealand. It has an almost indefinite span, being on this scale flexible rather like some of the experimental ultra-lightweight solar aircraft. One can fly a new wing section up to it, bolt it on and then remove the ferry power unit.
THIS I wanna see!!!
Title: Re: Giant aeroplanes
Post by: steelpillow on April 15, 2015, 03:16:31 am
Personally, I believe that giant, steam-powered airships offer the best solution to all your problems!  ;) ;D ;D

Ahh! The deck of a model warship grafted on top of a model Zeppelin, now that would be a whiff worth posting!

Mind you, one element missing from the designs I have seen is that all the deck fittings make the beast top-heavy. Essential to its flight stability are a couple of stub wings with powerful ailerons (or all-moving), linked to a Babbage engine to provide artificial stability. Naturally, the code for the engine was written by Ada, Countess Lovelace.
Title: Re: Giant aeroplanes
Post by: Hobbes on April 15, 2015, 03:21:04 am
TomZ made one (a Zeppelin aircraft carrier) a while ago...
Title: Re: Giant aeroplanes
Post by: zenrat on April 15, 2015, 03:35:40 am
;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D

(http://img537.imageshack.us/img537/9682/NlmYC4.jpg)

Air Viagra?


Title: Re: Giant aeroplanes
Post by: steelpillow on April 15, 2015, 03:44:45 am
Permanent soaring city A giant flying wing, this craft has no engines, but soars in the updraft found along Southern mountain ranges such as found in South America and New Zealand. It has an almost indefinite span, being on this scale flexible rather like some of the experimental ultra-lightweight solar aircraft. One can fly a new wing section up to it, bolt it on and then remove the ferry power unit.
THIS I wanna see!!!

Some engineering details:

The wing has a static centre of lift, meaning that it is stable in pitch and does not need a tail or a computer to keep it level. This is achieved using reflex camber on the rear section, so that the mid-line of the chord is a gentle s-curve, rather like this tilde character here: ~

Rather than having the whole structure flex, which would create unnerving creaks, groans and bangs in turbulent winds, it is made in sections with articulated joints like a railway train.

Some sections are bigger than the rest, creating relatively large - but very expensive - internal spaces.

There are some electric engines and propellers, and also wind turbines. Most are retractable, typically used in combination to maintain shape in varying local conditions. For example if a helicopter drops in on one section, it will deploy a propeller to help it maintain speed and height, while the neighbouring sections will deploy wind turbines which both supply power to the propeller and slightly drag these sections back to help smooth out the mechanical stresses. You may not realise it but such pop-out turbines are, on a much smaller scale, fitted as an emergency power supply on many aircraft flying today.

Other turbines would be permanent, supplying power to the aircraft's systems and inhabitants. But only limited power can be extracted, as the turbines act as airbrakes and the plane would drift backwards. Most likely, the inhabitants' lifestyle would require microwave beams from the ground, etc. to meet their full needs.

Larger deliveries of supplies would be by airship, as flying speeds will just be the natural windspeed in order to remain more or less stationary over the ground. Discharge of waste would be very strictly regulated - no blue ice here on a cold winter morning! Most would in fact go back down in the delivery airship as ballast.

After some years, a new ecology begins to establish itself on the ground beneath the aircraft's shadow. First it's the microorganisms, then the creepy-crawlies, but surprisingly quickly the characteristics of small birds, mammals, lizards and amphibians all begin to adapt to the rebalanced food chain. As those who were born in the sky city begin to grow old, identifiable new species begin to emerge in the twilight beneath.
Title: Re: Giant aeroplanes
Post by: martinbayer on April 15, 2015, 10:23:25 am
There has been a recent somewhat related discussion on Secretprojects regarding a supersonic mega-airliner referenced in passing in "2001":

http://www.secretprojects.co.uk/forum/index.php/topic,23978.0.html

https://www.facebook.com/2001Italia/photos/pcb.894967993867554/894967837200903/?type=1&theater

Martin
Title: Re: Giant aeroplanes
Post by: martinbayer on April 15, 2015, 11:04:33 am
Actually, it just dawned on me that the mention of an air disaster with over 2300 victims in Space Odyssey might have been motivated by Kubrick's documented fear/aversion of flying, especially since it purportedly occurred en route between his two places of residence of New York and London...

Martin
Title: Re: Giant aeroplanes
Post by: steelpillow on April 15, 2015, 12:09:32 pm
Interesting reading, thanks for the links.

Ca. 200 passengers per engine is similar to the A380. I wonder how our biggest military supersonic engines compare. But 12 engines is a reliability nightmare, any civil jet - whether SST or no - with more than 4 would be exceptional.

Modern 3D modelling combined with GPS would make it dead easy to designate 3D flight paths and interlace them to avoid the mid-air collisions that take up a lot of the discussion.

But only 2,500 passengers? ptui!  :wacko:
Title: Re: Giant aeroplanes
Post by: steelpillow on April 19, 2015, 01:59:48 pm
Anyway, my wrist forced me to open Inkscape and disengage sense of responsibility. Here is my 3,000-seat megaliner, fully certified for accident safety and evacuation:

(https://www.dropbox.com/s/q35w1dokcnp6j70/megaliner.png?dl=1)

My sense of self-preservation then took over and I realised that I did not have time to draw in the undercarriage before loading the dishwasher. Sorry about that.
Title: Re: Giant aeroplanes
Post by: ericr on April 19, 2015, 02:17:57 pm
 :o
Title: Re: Giant aeroplanes
Post by: kitnut617 on April 13, 2019, 10:27:46 am
So Stratolaunch flew for the first time today

https://www.youtube.com/watch?v=XfUy21HHtME
Title: Re: Giant aeroplanes
Post by: Captain Canada on April 13, 2019, 02:28:31 pm
Cool ! Probably doesn't pull many G's tho lol
Title: Re: Giant aeroplanes
Post by: NARSES2 on April 14, 2019, 05:41:26 am
Yup, saw that this morning and immediately wondered what Kit would do to it if there were a model of her. I need to get out more  :angel:
Title: Re: Giant aeroplanes
Post by: JayBee on April 14, 2019, 06:00:23 am
Yup, saw that this morning and immediately wondered what Kit would do to it if there were a model of her.

My thoughts entirely!  :rolleyes:
Title: Re: Giant aeroplanes
Post by: kitnut617 on April 14, 2019, 06:01:51 am
Yup, saw that this morning and immediately wondered what Kit would do to it if there were a model of her.

My thoughts entirely!  :rolleyes:

Well it is all wing already -----  ;D
Title: Re: Giant aeroplanes
Post by: NARSES2 on April 14, 2019, 06:03:35 am
Yup, saw that this morning and immediately wondered what Kit would do to it if there were a model of her.

My thoughts entirely!  :rolleyes:

Well it is all wing already -----  ;D

Yup but by removing a fuselage the wingspan increases in proportion to the fuselage remaining. I swear that's one of Einstein's  :rolleyes:
Title: Re: Giant aeroplanes
Post by: PR19_Kit on April 14, 2019, 07:30:53 am
Yup, saw that this morning and immediately wondered what Kit would do to it if there were a model of her.

My thoughts entirely!  :rolleyes:

Well it is all wing already -----  ;D

Yup but by removing a fuselage the wingspan increases in proportion to the fuselage remaining. I swear that's one of Einstein's  :rolleyes:


Nah, that's not the point, just make the wings LONGER!  ;D ;)

How long before A Model have a kit of it?
Title: Re: Giant aeroplanes
Post by: NARSES2 on April 15, 2019, 06:06:52 am

How long before A Model have a kit of it?

Have to admit A Model were the first company my brain thought of when it came around to the "I wonder who ?" question  ;)