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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. |
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. |
Quoting IAHflyer97 (Reply 2): That would be an awkward looking plane... |
Quoting IAHflyer97 (Reply 2): Would the aerodynamics make it possible? |
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 |
Quoting TWA772LR (Thread starter): A 737/A320 sized double decker could bring almost double the capacity into the same gate space for the aircraft. |
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, |
Quoting LOWS (Reply 7): I could see Ryanair taking a couple hundred... |
Quoting TheRedBaron (Reply 14): and put 3-3 on upper deck and 4 - 4 on the lower one...yuk! TRB |
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. |
Quoting flyingturtle (Reply 17): There are double-decker railway cars. And the pains to build them is apparently worth the effort |
Quoting flyingturtle (Reply 17): There are double-decker railway cars. |
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. |