Author Topic: Giant aeroplanes  (Read 1917 times)

0 Members and 1 Guest are viewing this topic.

Offline steelpillow

  • Makes own decals
  • ***
  • Posts: 588
    • Guy's blocki
Giant aeroplanes
« 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:
  • Exit doors positioned to allow quick evacuation in an emergency.
  • Wing root chord limited by need to evacuate.
  • Wing span limited by airport handling facilities.
  • Seat positions close enough to the aisles to allow quick evacuation.
  • Engines and fuel positioned away from the passengers, for survivability.
  • Huge inertia and scale require extra-powerful controls to respond quickly enough.

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:
  • Emergency exits are a problem. They cannot be directly downwards as the u/c might have collapsed on landing, if it was ever lowered.  They cannot be directly upwards due to the need for injured passengers to climb up and also the time for that and to slide off the wing. In the leading edge they would need to be exceptionally precisely engineered, making them expensive, heavy and easily damaged. In the trailing edge they would need hugely lengthened doors that nevertheless could be easily opened by hand.
  • Engines above and behind would crash down on the passengers if they broke free.
  • Fuel safely stored in the outer wings would be a long way from the engines.

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.
Cheers.

Offline Hobbes

  • Stores peanuts in his mailbox
  • What-IF SIG
  • Needs A Life Outside What-If
  • *****
  • Posts: 6338
    • Acme Engineering
Re: Giant aeroplanes
« Reply #1 on: April 14, 2015, 05:55:02 am »
Like this?



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

That's a real-world proposal for a 3-fuselage VC-10  :blink:

Offline steelpillow

  • Makes own decals
  • ***
  • Posts: 588
    • Guy's blocki
Re: Giant aeroplanes
« Reply #2 on: April 14, 2015, 08:23:28 am »
:) Getting there. Note enough wings, not enough engines, not enough bigness yet.
Cheers.

Offline PR19_Kit

  • Closeted Take That fan
  • What-IF SIG
  • Needs A Life Outside What-If
  • *****
  • Posts: 29260
  • Whiffing since the 70s
Re: Giant aeroplanes
« Reply #3 on: April 14, 2015, 09:18:11 am »
 ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D

Any aircraft can be improved by fitting longer wings, and/or a longer fuselage

...and I'm not a closeted 'Take That' fan, I'm a REAL fan! :)

Regards
Kit

Offline ericr

  • Needs A Life Outside What-If
  • *****
  • Posts: 2582
Re: Giant aeroplanes
« Reply #4 on: April 14, 2015, 10:57:44 am »
;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D



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

Offline PR19_Kit

  • Closeted Take That fan
  • What-IF SIG
  • Needs A Life Outside What-If
  • *****
  • Posts: 29260
  • Whiffing since the 70s
Re: Giant aeroplanes
« Reply #5 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
Any aircraft can be improved by fitting longer wings, and/or a longer fuselage

...and I'm not a closeted 'Take That' fan, I'm a REAL fan! :)

Regards
Kit

Offline pyro-manic

  • Needs A Life Outside What-If
  • *****
  • Posts: 5729
  • Master Procrastinator
    • Me on Flickr
Re: Giant aeroplanes
« Reply #6 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

« Last Edit: April 14, 2015, 04:53:56 pm by pyro-manic »
Some of my models can be found on my Flickr album >>>HERE<<<

Offline rickshaw

  • Needs A Life Outside What-If
  • *****
  • Posts: 9606
Re: Giant aeroplanes
« Reply #7 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

How to reduce carbon emissions - Tip #1 - Walk to the Bar for drinks.

Offline pyro-manic

  • Needs A Life Outside What-If
  • *****
  • Posts: 5729
  • Master Procrastinator
    • Me on Flickr
Re: Giant aeroplanes
« Reply #8 on: April 14, 2015, 05:54:19 pm »
Well obviously, but the thread is "Giant Aeroplanes". :P ;D
Some of my models can be found on my Flickr album >>>HERE<<<

Offline kitnut617

  • That's got his tum rumbling already just by the sound of it.
  • Needs A Life Outside What-If
  • *****
  • Posts: 11096
Re: Giant aeroplanes
« Reply #9 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.

 

If I'm not building models, I'm out riding my dirtbike

Offline Captain Canada

  • "but this time it's different. I was drunk when I agreed to it."
  • Needs A Life Outside What-If
  • *****
  • Posts: 28991
Re: Giant aeroplanes
« Reply #10 on: April 14, 2015, 07:22:18 pm »
Love the triple....imagine seeing ( and hearing ! ) that take off ?

 :wub:
CANADA KICKS arse !!!!

Long Live the Commonwealth !!!
Vive les Canadiens !
Where's my beer ?

Offline KiwiZac

  • The Zac Attack is Back!
  • Needs A Life Outside What-If
  • *****
  • Posts: 2059
  • aka K5054NZ, proud Whiffer since 2005
    • Zac on Facebook
Re: Giant aeroplanes
« Reply #11 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!!!
I find it very hard to believe Academy would make a mistake like that he said sarcastically...

Offline steelpillow

  • Makes own decals
  • ***
  • Posts: 588
    • Guy's blocki
Re: Giant aeroplanes
« Reply #12 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.
Cheers.

Offline Hobbes

  • Stores peanuts in his mailbox
  • What-IF SIG
  • Needs A Life Outside What-If
  • *****
  • Posts: 6338
    • Acme Engineering
Re: Giant aeroplanes
« Reply #13 on: April 15, 2015, 03:21:04 am »
TomZ made one (a Zeppelin aircraft carrier) a while ago...

Offline zenrat

  • Needs A Life Outside What-If
  • *****
  • Posts: 14611
  • Currently on double secret probation.
Re: Giant aeroplanes
« Reply #14 on: April 15, 2015, 03:35:40 am »
Fred

Another ill conceived, lazily thought out, crudely executed and badly painted piece of half arsed what-if modelling muppetry from zenrat industries.