Moderators: jsumali2, richierich, ua900, PanAm_DC10, hOMSaR

 
User avatar
TWA772LR
Topic Author
Posts: 7472
Joined: Thu Nov 17, 2011 6:12 am

Chances Of A Double-deck, Single Aisle Aircraft?

Sun Feb 15, 2015 1:38 am

Is is possible we could see a double-deck, single aisle aircraft? With a 3-3 configuration on the main deck and a 2-2 or 2-3 one on the upper? With slot restricted airports on the raise, I can see this being a popular option. A 737/A320 sized double decker could bring almost double the capacity into the same gate space for the aircraft.

Thoughts?
When wasn't America great?


The thoughts and opinions shared under this username are mine and are not influenced by my employer.
 
User avatar
1337Delta764
Posts: 5933
Joined: Mon Oct 31, 2005 4:02 am

RE: Chances Of A Double-deck, Single Aisle Aircraft?

Sun Feb 15, 2015 1:39 am

Quoting TWA772LR (Thread starter):
Is is possible we could see a double-deck, single aisle aircraft? With a 3-3 configuration on the main deck and a 2-2 or 2-3 one on the upper? With slot restricted airports on the raise, I can see this being a popular option. A 737/A320 sized double decker could bring almost double the capacity into the same gate space for the aircraft.

The main issue with such an aircraft would be the lack of cargo capacity for an aircraft of its size. I don't see it ever happening.
 
IAHflyer97
Posts: 740
Joined: Thu Jun 27, 2013 3:45 pm

RE: Chances Of A Double-deck, Single Aisle Aircraft?

Sun Feb 15, 2015 2:48 am

That would be an awkward looking plane... Would the aerodynamics make it possible?
A man is only as big as the amount of strings on his guitar.
 
User avatar
TWA772LR
Topic Author
Posts: 7472
Joined: Thu Nov 17, 2011 6:12 am

RE: Chances Of A Double-deck, Single Aisle Aircraft?

Sun Feb 15, 2015 2:56 am

Quoting 1337Delta764 (Reply 1):
The main issue with such an aircraft would be the lack of cargo capacity for an aircraft of its size. I don't see it ever happening.

True. Perhaps it could work with containerized luggage and a small bulk hold for cargo?

Quoting IAHflyer97 (Reply 2):
That would be an awkward looking plane...

So is the A380, and they said that about the DC-10, 747, etc... Beauty is in the eye of the beholder.

Quoting IAHflyer97 (Reply 2):
Would the aerodynamics make it possible?

We put a man on the moon and have come back from the brink of nuclear war (for now   ). Of course it's possible.
When wasn't America great?


The thoughts and opinions shared under this username are mine and are not influenced by my employer.
 
User avatar
SEPilot
Posts: 5680
Joined: Sat Dec 30, 2006 10:21 pm

RE: Chances Of A Double-deck, Single Aisle Aircraft?

Sun Feb 15, 2015 3:14 am

This was what the 747 originally was going to be; Joe Sutter proved that going single deck widebody was much more efficient. Double deck only becomes advantageous when the single deck gets so wide that there is too much wasted crown space. I am quite sure that a double deck single aisle would be heavier and have more drag than the equivalent single deck widebody. Plus you have the cargo space problem.
The problem with making things foolproof is that fools are so doggone ingenious...Dan Keebler
 
User avatar
DocLightning
Posts: 22026
Joined: Wed Nov 16, 2005 8:51 am

RE: Chances Of A Double-deck, Single Aisle Aircraft?

Sun Feb 15, 2015 3:33 am

Quoting SEPilot (Reply 4):

This was what the 747 originally was going to be; Joe Sutter proved that going single deck widebody was much more efficient. Double deck only becomes advantageous when the single deck gets so wide that there is too much wasted crown space

Even in the A380, the double-deck layout requires amazingly thick sidewalls. Joe Sutter mentions being fascinated at Airbus's decision to go full double-deck and at watching them deal with all of the engineering problems that confirmed his team's decision to not use that layout 40 years earlier.
-Doc Lightning-

"The sky calls to us. If we do not destroy ourselves, we will one day venture to the stars."
-Carl Sagan
 
User avatar
hufftheweevil
Posts: 785
Joined: Sun Oct 20, 2013 1:08 am

RE: Chances Of A Double-deck, Single Aisle Aircraft?

Sun Feb 15, 2015 5:33 am

Quoting TWA772LR (Thread starter):
A 737/A320 sized double decker could bring almost double the capacity into the same gate space for the aircraft.

But wouldn't this aircraft be quite heavier than a standard 737/A320, and therefore require a longer wing?
Huff
 
User avatar
LOWS
Posts: 1335
Joined: Sun Oct 23, 2011 5:37 am

RE: Chances Of A Double-deck, Single Aisle Aircraft?

Sun Feb 15, 2015 9:55 am

I could see Ryanair taking a couple hundred...
 
Ferminios
Posts: 121
Joined: Wed Apr 27, 2011 7:01 pm

RE: Chances Of A Double-deck, Single Aisle Aircraft?

Sun Feb 15, 2015 10:59 am

I would consider this highly unlikely, for a couple of reasons:

- This kind of aircraft would be a disaster to board, especially because I don't see smaller airports investing into jetways that can go up to the second level.
- You'll need space for staircases in the aircraft - in a narrowbody aircraft that would amount to a significant loss of space.
- Say that we have a 737-800 length aircraft, with 3-3 on the main deck, 2-2 upstairs: 30 rows on main deck, 24 on the top (if you're lucky). That's 276 seats. Tell me which missions this kind of aircraft would fly, that a high-density A332 can't .
- The gate space argument is invalid in this case. There's simply no way that this aircraft would be able to take off with 737-size wings. To support the additional weight of the pax and cargo you'll need larger wings and stronger engines.
- (As already mentioned) Belly space. You would probably be lucky to get all the bags of the passengers on board of this thing.
- I haven't yet talked about aerodynamics yet as I'm not an aerospace engineer - but from what I know I doubt it would work.
 
jeb94
Posts: 587
Joined: Mon Oct 04, 2004 9:19 pm

RE: Chances Of A Double-deck, Single Aisle Aircraft?

Sun Feb 15, 2015 12:37 pm

Why? Isn't this what wide body jets are for? You have two aisles either way.
 
Burkhard
Posts: 1916
Joined: Fri Nov 17, 2006 9:34 pm

RE: Chances Of A Double-deck, Single Aisle Aircraft?

Sun Feb 15, 2015 12:49 pm

The bigger you deviate the body shape from a pure tube, the bigger forces it must take, which means it gets much heavier. So such a plane might have 60% more capacity at 100% more weight - better make twin aisle aircraft.
 
User avatar
par13del
Posts: 10484
Joined: Sun Dec 18, 2005 9:14 pm

RE: Chances Of A Double-deck, Single Aisle Aircraft?

Sun Feb 15, 2015 1:04 pm

Quoting TWA772LR (Thread starter):
With a 3-3 configuration on the main deck and a 2-2 or 2-3 one on the upper? With slot restricted airports on the raise,

Rather than go to the specifics of the a/c, I'll focus on your premise behind the a/c because if accurate, it create the business decision which will have to fund development.
Where are slot restricted airports increasing and how much traffic do they have on short range a/c?
Largest single market for short range a/c is the USA and North America in general, minimal slost and none on the horizon, however, politics may see some artificial constraints for frequency, time will tell.
In Europe, one of the largest short range operators - FR - does not operate into the major slot restricted airports.
In the rest of the world, such a/c are increasingly used between nations and slots are not an issue.
I do not see a business case for a double decker short range a/c my reasons can be debunked.
 
fanofjets
Posts: 2030
Joined: Thu Apr 13, 2000 2:26 am

RE: Chances Of A Double-deck, Single Aisle Aircraft?

Sun Feb 15, 2015 6:39 pm

It is worth noting that before the advent of the Boeing 747 and other widebodies, Boeing considered a double-deck version of the Boeing 707-320 and Vickers was looking into a double-deck version of the Super VC-10. Needless to say, neither design left the drawing board.

http://www.vc10.net/History/DDVC10_page5.html

The closest to a true double-deck single-aisle aircraft was this:

View Large View Medium
Click here for bigger photo!

Photo © R.A.Scholefield



...though several of the Shorts flying boats (most notably the Sandringham) did have an upper-deck lounge, the equivalent of the lower-deck lounge of the Boeing Stratocruiser.
The aeroplane has unveiled for us the true face of the earth. -Antoine de Saint-Exupery
 
incitatus
Posts: 3391
Joined: Wed Feb 09, 2005 1:49 am

RE: Chances Of A Double-deck, Single Aisle Aircraft?

Sun Feb 15, 2015 9:00 pm

The cross section of the fuselage is key to two parameters that influence aircraft efficiency:

1. Total area of the cross section
2. Weight of the fuselage

I am skeptical as whether a double-decker single aisle can do better than a single-decker twin-aisle in these two categories.
I do not consume Murdoch products including the Wall Street Journal
 
User avatar
TheRedBaron
Posts: 3276
Joined: Tue Mar 29, 2005 6:17 am

RE: Chances Of A Double-deck, Single Aisle Aircraft?

Sun Feb 15, 2015 9:28 pm

Quoting LOWS (Reply 7):
I could see Ryanair taking a couple hundred...

and put 3-3 on upper deck and 4 - 4 on the lower one...yuk!

TRB
The best seat in a Plane is the Jumpseat.
 
Cipango
Posts: 1498
Joined: Wed Jul 22, 2009 3:55 pm

RE: Chances Of A Double-deck, Single Aisle Aircraft?

Sun Feb 15, 2015 9:36 pm

Quoting TheRedBaron (Reply 14):
and put 3-3 on upper deck and 4 - 4 on the lower one...yuk!

TRB

Thankfully this isn't allowed.

You must be no more than 2 seats away from the aisle.
Let's fly! Unless it's on a CRJ 200, then I'll stay down here.
 
User avatar
Btriple7
Posts: 1207
Joined: Tue Sep 06, 2005 3:58 am

RE: Chances Of A Double-deck, Single Aisle Aircraft?

Sun Feb 15, 2015 9:56 pm

See Reply 1 from this thread: A380/ B747 - Two-decks Question (by BubbleFrog Dec 15 2014 in Tech Ops)

Quoting Matt6461:
The pre-747 double-decker was basically two 707's stacked on top of each other. Aside from looking weird, this would have some serious disadvantages versus a 747:
-no or low revenue cargo volume
-difficult and weighty to pressurize
-still a single aisle design, so cramped pax layout for long haul

Those first two objections could be raised against the A380 as well of course. I think the difference (between pre-747 DD and A380/MD-12/NLA study) is as follows:

-double deckers have economies of scale in aerodynamics (less wetted area) and structure (shorter moment arm for equal pax load)
-these are counterbalanced by pressurization difficulty (assuming non-circular cross section) and loss of cargo
-When a single deck layout of somewhat-circular cross section reaches a size where you're flying too much air in the crown over your single deck, you then face a choice of either (1) accepting this waste of pressurized volume or (2) adopting an elliptical cross section with longest axis on horizontal (think of an A380 sideways). If the elliptical fuselage saves more weight and drag, despite pressurization difficulty, than a circular (or double-bubble), then you're already at s a size point where one of the big disadvantages of a double-decker has passed. Plus, the double decker can use floor beams to reinforce the ellipse's hoop stress laterally, whereas this would be problematic in the vertical direction through the cabin on the single deck. Finally, the double decker would more efficiently use the same pressurized volume for a given ellipse (the single deck would still have air in the crown, just less of it than if circular).
-Before the "crown air" factor dominates, single decks are best. As size increases and you can efficiently recover "crown air" along with double decker's other benefits, a double decker is best. The "stacked 707" was well short of exhausting single-deck economies of scale.

//Bt7
Just...fly.
 
User avatar
flyingturtle
Posts: 6024
Joined: Mon Oct 31, 2011 1:39 pm

RE: Chances Of A Double-deck, Single Aisle Aircraft?

Sun Feb 15, 2015 11:11 pm

There are double-decker railway cars.

And the pains to build them is apparently worth the effort - and they even have 2+2 seating in economy. Overall, they have +/- a 60% increase in passenger capacity due to the stairs and sometimes having two toilets per wagon. Then, some space must be set aside for the tilting mechanism (in a curve, a railway wagon is trying to tilt outwards - which is more pronounced in these high double-deckers, which must be countered by an active tilting mechanism for comfort).

And just my thoughts...

Some have suggested that FR or U2 would take hundreds of double-decker 320 or 737. The 310 had a capacity of 265 pax (full economy), the 321 has 220. Then comes the 330 with 404 seats.

Is there actually a gap in the market for a full-economy 300-seater? I think so - and it is filled by the 767. Could Airbus take the 300-seater niche away from Boeing?

A double-decker 321 could be designed in a sexy way, I'm sure. But I'm dreaming... 


David
Reading accident reports is what calms me down
 
OldAeroGuy
Posts: 3928
Joined: Sun Dec 05, 2004 6:50 am

RE: Chances Of A Double-deck, Single Aisle Aircraft?

Mon Feb 16, 2015 12:52 am

Quoting flyingturtle (Reply 17):
There are double-decker railway cars.

And the pains to build them is apparently worth the effort

But they are not pressurized.
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
phxtravelboy
Posts: 338
Joined: Tue Nov 29, 2005 7:42 am

RE: Chances Of A Double-deck, Single Aisle Aircraft?

Mon Feb 16, 2015 2:06 am

I had to read the title of this thread twice as I thought I was misreading it. HUH??? This is pretty much one of the dumbest things I think I've read on this post. The chances are right up there next to ZILCH. If an airline decided they needed additional capacity on a route, they'd simply send a larger aircraft, meaning one with 2 aisles that already exists.I don't see the point of putting the other aisle in an upper deck instead of next to the other aisle as we currently have.
 
alfa164
Posts: 3797
Joined: Sat Oct 06, 2012 2:47 am

RE: Chances Of A Double-deck, Single Aisle Aircraft?

Mon Feb 16, 2015 3:29 am

Quoting flyingturtle (Reply 17):
There are double-decker railway cars.

For good reasons: the width of the tracks (and the proximity of parallel tracks), and the proximity of immovable train platforms at each station. A "wide-bodied" train would bump into every platform and every passing train along its route... so a train must build "up", rather than out.

For aircraft, just the opposite is true.

Quoting Ferminios (Reply 8):

I would consider this highly unlikely, for a couple of reasons:

- This kind of aircraft would be a disaster to board, especially because I don't see smaller airports investing into jetways that can go up to the second level.
- You'll need space for staircases in the aircraft - in a narrowbody aircraft that would amount to a significant loss of space.
- Say that we have a 737-800 length aircraft, with 3-3 on the main deck, 2-2 upstairs: 30 rows on main deck, 24 on the top (if you're lucky). That's 276 seats. Tell me which missions this kind of aircraft would fly, that a high-density A332 can't .
- The gate space argument is invalid in this case. There's simply no way that this aircraft would be able to take off with 737-size wings. To support the additional weight of the pax and cargo you'll need larger wings and stronger engines.
- (As already mentioned) Belly space. You would probably be lucky to get all the bags of the passengers on board of this thing.
- I haven't yet talked about aerodynamics yet as I'm not an aerospace engineer - but from what I know I doubt it would work.

  
I'm going to have a smokin' hot body again!
I have decided to be cremated....

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