A double-deck aircraft has two decks for passengers; the second deck may be only a partial deck, and may be above or below the main deck. Most commercial aircraft have one passenger deck and one cargo deck for luggage and ULD containers, but a few have two decks for passengers, typically above or below a third deck for cargo.
History
Many early flying boat airliners, such as the Boeing 314 Clipper and Short Sandringham, had two decks. Following World War II, the Stratocruiser, a partially double-decked derivative of the B-29 Superfortress, became popular with airlines around the world.
The first full double-deck aircraft was the French Breguet Deux-Ponts, in service from 1953. The first partial double-deck jet airliner was the widebody Boeing 747, in service from 1970, with the top deck smaller than the main deck. Boeing originally designed the distinctive 747 bubble top with air cargo usage in mind. The small top deck permitted the cockpit and a few passengers and nose doors with unobstructed access to the full length of the hold. Most 747s are passenger jets, and a small percentage are cargo jets with nose doors.
The first full double-deck jet airliner is the Airbus A380, which has two passenger decks extending the full length of the fuselage, as well as a full-length lower third deck for cargo. It entered regular service in late-October 2007.
List of double-deck aircraft
Double-deck flying boats Latécoère 521/522 Martin M-130 Latécoère 631 Sud-Est SE.200 Amphitrite Boeing 314 Clipper Dornier Do-X Short Sandringham Short Empire C-Class and the related G-class Saunders-Roe Princess - did not enter service.
Partial second passenger deck
Caproni Ca.48/58 Extra seats on top of the passenger cabin.
Airbus A330 and Airbus A340 Optional lower deck lavatories and crew rest Airbus A350 Optional upper deck crew rest Boeing 377 Stratocruiser Lower deck could be configured for lounge areas or additional seating
Boeing 747, SNC E-4C Survivable Airborne Operations Center, Boeing 747SP, Boeing E-4, Boeing 747-400, Boeing Dreamlifter, 747 Supertanker, Boeing YAL-1 and Boeing 747-8 Partial upper deck lounge areas or seating Optional upper deck crew rest and galleys Boeing 767, Northrop Grumman E-10 MC2A, Boeing KC-767, Boeing E-767 and Boeing KC-46 Pegasus Optional lower level crew rest area sleeps six Boeing 777 and Boeing 777X Optional lower deck lavatories and galley Optional upper deck crew rest Boeing 787 Optional upper deck crew rest Junkers G.38 Ilyushin Il-86 Lower deck galley Lower deck "self loading luggage storage" Lockheed L-1011 Tristar Lower deck galley Lower deck lounge (Pacific Southwest Airlines) (LTU International) McDonnell Douglas DC-10 Lower deck galleys Tupolev Tu-114 Lower deck galleys. Lower deck aircrew rest area.
Full second passenger deck Breguet 761, 763 and 765 Airbus A380
Cargo aircraft with a separate passenger deck Antonov An-22 Antonov An-225 Mriya Antonov An-124 Ruslan Lockheed C-5 Galaxy and Lockheed C-5M Super Galaxy Boeing C-97 Stratofreighter Douglas C-124 Globemaster II Short Belfast Lockheed R6V Constitution Blackburn Beverley - military transport, the main deck could be used for cargo or troops
Double-deck cargo aircraft Aviation Traders Carvair Armstrong Whitworth AW.660 Argosy Bristol Freighter Convair XC-99 Douglas C-124 Globemaster II
Canceled projects for double-deck passenger aircraft Bach Super Transport McDonnell Douglas MD-12 Sukhoi KR-860 Vickers VC-10 Superb: see Tupolev Tu-404
See also Large aircraft Wide-body aircraft
References