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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.
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.[ citation needed ] 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. [1]
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Canceled projects for double-deck passenger aircraft
The Boeing 747 is a large, long-range wide-body airliner designed and manufactured by Boeing Commercial Airplanes in the United States between 1968 and 2023. After introducing the 707 in October 1958, Pan Am wanted a jet 2+1⁄2 times its size, to reduce its seat cost by 30%. In 1965, Joe Sutter left the 737 development program to design the 747, the first twin-aisle airliner. In April 1966, Pan Am ordered 25 Boeing 747-100 aircraft, and in late 1966, Pratt & Whitney agreed to develop the JT9D engine, a high-bypass turbofan. On September 30, 1968, the first 747 was rolled out of the custom-built Everett Plant, the world's largest building by volume. The first flight took place on February 9, 1969, and the 747 was certified in December of that year. It entered service with Pan Am on January 22, 1970. The 747 was the first airplane called a "Jumbo Jet" as the first wide-body airliner.
An airliner is a type of aircraft for transporting passengers and air cargo. Such aircraft are most often operated by airlines. Although the definition of an airliner can vary from country to country, an airliner is typically defined as an airplane intended for carrying multiple passengers or cargo in commercial service. The largest of them are wide-body jets which are also called twin-aisle because they generally have two separate aisles running from the front to the back of the passenger cabin. These are usually used for long-haul flights between airline hubs and major cities. A smaller, more common class of airliners is the narrow-body or single-aisle. These are generally used for short to medium-distance flights with fewer passengers than their wide-body counterparts.
A wide-body aircraft, also known as a twin-aisle aircraft, is an airliner with a fuselage wide enough to accommodate two passenger aisles with seven or more seats abreast. The typical fuselage diameter is 5 to 6 m. In the typical wide-body economy cabin, passengers are seated seven to ten abreast, allowing a total capacity of 200 to 850 passengers. The largest wide-body aircraft are over 6 m (20 ft) wide, and can accommodate up to eleven passengers abreast in high-density configurations.
The Airbus A300-600ST, or Beluga, is a specialised wide-body airliner used to transport aircraft parts and outsize cargoes. It received the official name of Super Transporter early on; however, the name Beluga, a whale it resembles, gained popularity and has since been officially adopted.
A jet airliner or jetliner is an airliner powered by jet engines. Airliners usually have two or four jet engines; three-engined designs were popular in the 1970s but are less common today. Airliners are commonly classified as either the large wide-body aircraft, medium narrow-body aircraft and smaller regional jet.
The Boeing 747-400 is a large, long-range wide-body airliner produced by Boeing Commercial Airplanes, an advanced variant of the initial Boeing 747. The "Advanced Series 300" was announced at the September 1984 Farnborough Airshow, targeting a 10% cost reduction with more efficient engines and 1,000 nautical miles [nmi] of additional range. Northwest Airlines became the first customer with an order for 10 aircraft on October 22, 1985. The first 747-400 was rolled out on January 26, 1988, and made its maiden flight on April 29, 1988. Type certification was received on January 9, 1989, and it entered service with NWA on February 9, 1989.
The Boeing 377 Stratocruiser was a large long-range airliner developed from the C-97 Stratofreighter military transport, itself a derivative of the B-29 Superfortress. The Stratocruiser's first flight was on July 8, 1947. Its design was advanced for its day; its relatively innovative features included two passenger decks and a pressurized cabin. It could carry up to 100 passengers on the main deck plus 14 in the lower deck lounge; typical seating was for 63 or 84 passengers or 28 berthed and five seated passengers.
The Boeing C-97 Stratofreighter was a long-range heavy military cargo aircraft developed from the B-29 and B-50 bombers. Design work began in 1942, the first of three prototype XC-97s flew on 9 November 1944, and the first of six service-test YC-97s flew on 11 March 1947. All nine were based on the 24ST alloy structure and Wright R-3350 engines of the B-29, but with a larger-diameter fuselage upper lobe and they had the B-29 vertical tail with the gunner's position blanked off. The first of three heavily revised YC-97A incorporating the re-engineered wing, taller vertical tail and larger Pratt & Whitney R-4360 engines of the B-50 bomber, flew on 28 January 1948 and was the basis of the subsequent sole YC-97B, all production C-97s, KC-97s and civilian Stratocruiser aircraft. Between 1944 and 1958, 888 C-97s in several versions were built, 811 being KC-97 tankers. C-97s served in the Berlin Airlift, the Korean War, and the Vietnam War. Some aircraft served as flying command posts for the Strategic Air Command, while others were modified for use in Aerospace Rescue and Recovery Squadrons (ARRS).
Boeing Commercial Airplanes (BCA) is a division of The Boeing Company. It designs, assembles, markets, and sells jet airliners and business jets, and also provides product-related maintenance and training to customers worldwide. BCA operates out of its division headquarters in Renton, Washington, and has more than a dozen engineering, manufacturing, and assembly facilities located throughout the United States and internationally. It includes the assets of the Douglas Aircraft division of the former McDonnell Douglas Corporation, which merged with Boeing in 1997. As of the end of 2021, BCA employed about 35,926 people.
The McDonnell Douglas MD-12 was a large wide-body airliner concept planned by the McDonnell Douglas company in the 1990s. It was first conceived as a trijet larger than the MD-11, then stretched to a quadjet airliner. It was to be similar in size to the Boeing 747, but with greater passenger capacity through two full-length passenger decks. However, the MD-12 received no orders and was canceled. McDonnell Douglas then studied larger MD-11 derivatives named MD-XX without proceeding.
The Boeing NLA, or New Large Airplane, was a 1990s concept for an all-new quadjet airliner in the 500+ seat market. Somewhat larger than the 747, this aircraft was similar in concept to the McDonnell Douglas MD-12 and later Airbus A380. In 1993, Boeing chose not to pursue development of this concept, focusing instead on the Boeing 747-500X and -600X, and then on the 747X and 747X Stretch, and subsequently on the Boeing 747-8. The project names for this aircraft were NLA and Boeing 763-246C.
A propliner is a large, propeller-driven airliner. Typically, the term is used for piston engine airliners that flew before the large scale advent of airliners of the jet age. With the notable exception of the de Havilland Albatross and Fokker F-10 of the late 1920s to 1930s, which were largely fabricated of wood, propliners generally featured all-metal wings and structural members, totally or partially retractable landing gear, and two, three, or four engines. A few might deviate from these characteristics with fixed landing gear, such as the Albatross, Fokker 110, and Lockheed Vega.
A cargo aircraft is a fixed-wing aircraft that is designed or converted for the carriage of cargo rather than passengers. Such aircraft usually do not incorporate passenger amenities and generally feature one or more large doors for loading cargo. Freighters may be operated by civil passenger or cargo airlines, by private individuals or by the armed forces of individual countries.
The Boeing 747-8 is a wide-body airliner formerly developed by Boeing Commercial Airplanes, and the largest variant of the 747. After introducing the 747-400, Boeing considered larger 747 versions as alternatives to the proposed double-deck Airbus A3XX, later developed as the A380. The stretched 747 Advanced was launched as the 747-8 on November 14, 2005, for a market forecast of 300 aircraft. The first 747-8F Freighter performed its maiden flight on February 8, 2010, and the passenger 747-8I Intercontinental followed suit on March 20, 2011. The cargo version was first delivered in October 2011 and the airliner began commercial service in June 2012.
An airstair is a set of steps built into an aircraft so that passengers may board and alight the aircraft. The stairs are often built into a clamshell-style door on the aircraft. Airstairs eliminate the need for passengers to use a mobile stairway or jetway to board or exit the aircraft, providing more independence from ground services. Some of the earliest aircraft to feature airstairs were the Martin 2-0-2 and Martin 4-0-4. Some models of the Douglas DC-3 were also retrofitted with airstairs. As airport infrastructure has developed, the need for airstairs has decreased, as jetways or mobile stairways are often available.
A trijet is a jet aircraft powered by three jet engines. In general, passenger airline trijets are considered to be second-generation jet airliners, due to their innovative engine locations, in addition to the advancement of turbofan technology. Trijets are more efficient than quadjets, but not as efficient as twinjets, which replaced trijets as larger and more reliable turbofan engines became available.
A twinjet or twin-engine jet is a jet aircraft powered by two engines. A twinjet is able to fly well enough to land with a single working engine, making it safer than a single-engine aircraft in the event of failure of an engine. Fuel efficiency of a twinjet is better than that of aircraft with more engines. These considerations have led to the widespread use of aircraft of all types with twin engines, including airliners, fixed-wing military aircraft, and others.
Air France has been in operation since 1933. Its aircraft have been involved in a number of major accidents and incidents. The deadliest accident of the airline occurred on June 1, 2009, when Air France Flight 447, an Airbus A330-203, flying from Rio de Janeiro to Paris crashed into the Atlantic Ocean with 228 fatalities. A selected list of the most noteworthy of these events is given below.
Northwest Airlines was a major United States airline which existed from 1926 until 2010, when it merged with Delta Air Lines and became part of Delta Air Lines fleet. At the time of the merger it had a total of 309 aircraft. It was also the last U.S. airline to have a dedicated cargo fleet and routes.
A four-engined jet, sometimes called a quadjet, is a jet aircraft powered by four engines. The presence of four engines offers increased power, allowing such aircraft to be used as airliners, freighters, and military aircraft. Many of the first purpose-built jet airliners had four engines, among which stands the De Havilland Comet, the world's first commercial jetliner. In the decades following their introduction, their use has gradually declined due to a variety of factors, including the approval of twin-engine jets to fly farther from diversion airports as reliability increased, and an increased emphasis on fuel efficiency.
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