Airliner

Considered among the most revolutionary airliners, the Douglas DC-3 is the most produced airliner in history. First flying in 1935, it remains in active service today.
Pictured on its maiden voyage in 1967, the Boeing 737 is the most produced jet airliner in history.

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 aircraft intended for carrying multiple passengers or cargo in commercial service.

The largest airliners are wide-body jets. These aircraft are frequently called twin-aisle aircraft because they generally have two separate aisles running from the front to the back of the passenger cabin. These aircraft are usually used for long-haul flights between airline hubs and major cities with many passengers.

A smaller, more common class of airliners is the narrow-body or single aisle aircraft. These smaller airliners are generally used for short to medium-distance flights with fewer passengers than their wide-body counterparts.

Regional airliners typically seat fewer than 100 passengers and may be powered by turbofans or turboprops. These airliners are the non- mainline counterparts to the larger aircraft operated by the major carriers, legacy carriers, and flag carriers and are used to feed traffic into the large airline hubs. These regional routes then form the spokes of a hub-and-spoke air transport model.

The lightest ( light aircraft, list of light transport aircraft) of short haul regional feeder airliner type aircraft that carry 19 or fewer passenger seats are called commuter aircraft, commuterliners, feederliners, and air taxis, depending on their size, engines, how they are marketed, region of the world, and seating configurations. The Beechcraft 1900, for example, has only 19 seats.

History

Inter-war period

When the Wright brothers made the world’s first sustained heavier-than-air flight, they laid the foundation for what would become a major transport industry. Their flight in 1903 was just 11 years before what is often defined as the world’s first airliner. [1] These airliners would have a significant impact on global society, economics, and politics. [2]

Sikorsky Ilya Muromets while in use as a bomber by Russia

If an airliner is defined as an aircraft intended for carrying multiple passengers in commercial service, the Russian Sikorsky Ilya Muromets was the first aircraft meeting that definition[ citation needed]. The Ilya Muromets was a luxurious aircraft with a separate passenger saloon, wicker chairs, bedroom, lounge and a toilet. The aircraft also had heating and electrical lighting. The Ilya Muromets first flew on December 10, 1913. On February 25, 1914, it took off for its first demonstration flight with 16 passengers aboard. From June 21 – June 23, it made a round-trip from Saint Petersburg to Kiev in 14 hours and 38 minutes with one intermediate landing. However, it was never used as a commercial airliner due to the onset of World War I.

In 1915 the very first airliner (for commercial use) was used by Elliot Air Service. The aircraft was a Curtiss JN 4, a small biplane which was used mainly in World War I as a trainer. Later, it was also used as a tour and familiarization flight aircraft in the early 1920s.

In 1919, after World War I, the Farman F.60 Goliath, originally designed as a long-range heavy bomber, was converted for commercial use into a passenger airliner. It could seat 14 passengers from 1919, and approximately 60 were built. Initially several publicity flights were made, including one on 8 February 1919, when the Goliath flew 12 passengers from Toussus-le-Noble to RAF Kenley, near Croydon, despite having no permission from the British authorities to land.

Another important airliner built in 1919 was the Airco DH.16; a re-designed Airco DH.9A with a wider fuselage to accommodate an enclosed cabin seating four passengers, plus pilot in an open cockpit. In March 1919, the prototype first flew at Hendon Aerodrome. Nine aircraft were built, all but one being delivered to the nascent airline, Aircraft Transport & Travel Limited (AT&T). AT&T used the first aircraft for pleasure flying, and on 25 August 1919 it inaugurated the first scheduled international airline service from London to Paris. [3] One aircraft was sold to the River Plate Aviation Company in Argentina, to operate a cross-river service between Buenos Aires and Montevideo. [3] Meanwhile, the competing Vickers converted its successful WW1 bomber, the Vickers Vimy, into a civilian version, the Vimy Commercial. It was redesigned with a larger diameter fuselage (largely of spruce plywood), and first flew from the Joyce Green airfield in Kent on 13 April 1919. [4] [5]

The world's first all-metal transport aircraft was the Junkers F.13, also from 1919 with 322 built. The Dutch Fokker company produced the Fokker F.II followed by its development the F.III. These aircraft were used by the Dutch airline KLM when it re-opened an Amsterdam-London service in 1921. The Fokkers were soon flying to destinations across Europe, including Bremen, Brussels, Hamburg and Paris. They proved to be very reliable aircraft.

The Handley Page company in Britain produced the Handley Page Type W as the company's first civil transport aircraft. It housed two crew in an open cockpit and 15 passengers in an enclosed cabin. Powered by two 450 hp (340 kW) Napier Lion engines the prototype first flew on 4 December 1919, shortly after it was displayed at the 1919 Paris Air Show at Le Bourget. It was the world's first airliner to be designed with an on-board lavatory.

Meanwhile, in France the Bleriot-SPAD S.33 was a great success throughout the 1920s, initially serving the Paris- London route, and later on continental routes. The enclosed cabin could carry four passengers with an extra seat in the cockpit.

By 1921, it was becoming apparent that aircraft capacity needed to be larger for the economics to remain favourable. The English company de Havilland, therefore built the ten-passenger DH.29 monoplane, while starting work on the design of the DH.32, an eight-seater biplane with a less powerful but more economical Rolls-Royce Eagle engine. Owing to the urgent need for more capacity, however, work on the DH.32 was stopped and the DH.34 biplane was designed, accommodating ten passengers. The Fokker trimotor was an important and popular transport, manufactured under license in Europe and America.

Throughout the 1920s, companies in Britain and France were at the forefront of the civil airliner industry, [6] often considerably aided by government subsidies.

In America, the Ford Trimotor was an important early airliner. With two engines mounted on the wings and one in the nose and a slabsided body, it carried eight passengers and was produced from 1925 to 1933. It was used by the predecessor to Trans World Airlines, and by other airlines long after production ceased. Pan Am opened up transoceanic service in the late 1920s and early '30s, based on a series of large seaplanes – the Sikorsky S-38 through Sikorsky S-42.

By the 1930s, the airliner industry had matured and large consolidated national airlines were established with regular international services that spanned the globe, including Imperial Airways in Britain, Lufthansa in Germany, KLM in the Netherlands and United Airlines in America. Multi-engined aircraft were now capable of transporting dozens of passengers in comfort. [7]

In Britain, the de Havilland Dragon was a successful aircraft during the 1930s. Its simple design used a plywood box fuselage. It could carry six passengers each with 45 pounds (20 kg) of luggage on the London-Paris route on a fuel consumption of just 13 gal (49 l) per hour. The wing panels outboard of the engines could be folded for storage. The type was attractive as a short-haul low capacity airliner and was soon in service worldwide. British production of the DH.84 ended when it was replaced on the assembly line by the more powerful and elegant de Havilland Dragon Rapide.

The first modern-looking sleek metal airliners also came into service in the 1930s. In the United States, the Boeing 247 and the 14-passenger Douglas DC-2 flew, and in 1935 the more powerful, faster, 21–32 passenger Douglas DC-3 appeared. DC-3s were produced in quantity for World War II and sold as surplus afterward. The Douglas DC-3 was a particularly important airplane, because it was the first airliner to be profitable without a government subsidy. [8]

Long-haul flights were expanded during the 1930s as both Pan American Airways and Imperial Airways competed in the provision of transatlantic travel using flying boats such as the British Short Empire and the American Boeing 314. This prefigured the dramatic growth of transatlantic travel in the post-war period.

The post-war jet age

United Kingdom

Prototype of the de Havilland Comet in 1949, the first jet airliner in the world

In the United Kingdom, the Brabazon Committee was formed in 1942 under John Moore-Brabazon, 1st Baron Brabazon of Tara to investigate the future needs of the British Empire's civilian airliner market. The study was an attempt at defining in broad overview; the impact of projected advances in aviation technology and to forecast the global needs of the post war British Empire (in South Asia, Africa, the Near and Far East) and Commonwealth ( Australia, Canada, New Zealand) in the area of air transport, for passengers, mail, and cargo. The crucial problem that the planners faced was that an agreement had been reached between the United States and the United Kingdom in 1942 to split responsibility for building multi-engine aircraft types for British use: the US would concentrate on transport aircraft while the UK would concentrate on their heavy bombers. This decision meant that the United Kingdom would be left at the close of the war with little experience in the design, manufacture and final assembly of transport aircraft.

The final report called for the construction of four general designs studied by the committee and members of the state-owned airlines British Overseas Airways Corporation (BOAC) and later British European Airways (BEA). The first three designs were piston-powered aircraft of varying sizes for different markets, while the Type IV design, at the urging of Geoffrey de Havilland whose company was involved in development the first jet fighters, was for a jet-powered 100-seat design.

The Type I design, after a brief contest was given to the Bristol Aeroplane Company, building on submissions they had made during the war for a "100 ton bomber". This evolved into the creation of the Bristol Brabazon.

The Type II process was complicated by the proposition of Vickers that there should be a move to the newly developed turboprop power. The specification was therefore split in two, with the conventional piston design going to the eventual de Havilland Dove and Airspeed Ambassador. The revolutionary VC.2 Viceroy, first flown in 1948 was the first turboprop design anywhere. The Type III requirement was developed as the Avro Tudor.

The Type IV for the jet-powered aircraft went to de Havilland and became, in 1949, the world's first jet airliner, the Comet. It featured an aerodynamically clean design with four de Havilland Ghost turbojet engines buried in the wings, a pressurised fuselage, and large square windows. For the era, it offered a relatively quiet, comfortable passenger cabin and showed signs of being a commercial success at its 1952 debut. However, a year after entering commercial service the Comets began suffering problems, with three of them breaking up during mid-flight in well-publicised accidents. This was later found to be due to catastrophic metal fatigue, not well understood at the time, in the airframes. The Comet was withdrawn from service and extensively tested to discover the cause. Rival manufacturers meanwhile heeded the lessons learned from the Comet while developing their own aircraft. Although sales never fully recovered, the improved Comet 2 and the prototype Comet 3 culminated in the redesigned Comet 4 series which debuted in 1958 and had a productive career of over 30 years.

This disaster, coupled with the fact that the UK's domestic market was much smaller than the US's, meant that by the 1960s it was increasingly clear that the UK had lost the airliner market to the US, and later designs like the BAC 1-11, Vickers VC10, and Hawker Siddeley Trident although successful would be unable to win a substantial part of it back again. Another committee was formed to consider supersonic designs, STAC, and worked with Bristol to create the Bristol 223 design for a 100-passenger transatlantic airliner. However, this was going to be so expensive to produce that the effort was later merged with similar efforts in France to create the first supersonic airliner—the Concorde. [9] [10]

United States

The United States, conversely, gained a huge advantage in design and production in the airline industry in the years leading up to the war, but many of the developments would be put off until after the war as the manufacturing efforts were placed on the war effort. The advancements that the United States would make in this industry were in large part due to the cooperation of the airlines discussing what they desired with the airliner manufacturers.

United Airlines DC-6, Stapleton Airport, Denver, September 1966

Soon after the war though Douglas made a large advancement with the DC-4, although this could not cross the Atlantic at every point, it was able to make a nonstop flight from New York to the United Kingdom. Due to the war going on, the first batch of these planes went to the U.S. Army and Air Forces, and was named the C-54 Skymaster. Some of these that were used in the war would later be converted for the airline industry, along with the passenger and cargo versions that were placed on the market once the war ended. Douglas would later develop a version of this plane that was pressurized and five feet longer; this redesigned plane would become the DC-6. These DC-6s would be grounded for six months to rectify a few safety issues that were causing in-flight fires.

Soon after the DC-4, Lockheed developed the distinctive triple-tail Constellation. An aviation breakthrough, it was the first commercially successful pressurized airliner, allowing it to fly higher than other airliners. Its fuselage was some 127 inches wider than the DC-4s. Drafted by the military in World War II, it experienced a similar late entry into the civilian airline industry. Safety concerns grounded it for six months soon after it entered service while problems were investigated and repaired.

In 1947 the Boeing 377 Stratocruiser entered the industry with a completely different design than Douglas and Lockheed aircraft. Based on the C-97 Stratofreighter military transport, it had a double deck and pressurized fuselage. Luxury and a 100-passenger capacity distinguished it from its rivals. While 900 C-97s were supplied to the military, only 55 were produced for civil aviation.

The American companies had done a great job of advancing the status of transcontinental travel, but there was also the aging fleet of DC-3s that had to be addressed. Convair decided that they were going to address this market, and would begin producing the Convair 240, which was a 40-person fully pressurized plane. There were 566 of these planes that would fly, including two that were equipped with jet-assisted take off units. Convair would later develop the Convair 340, which was slightly larger and could accommodate between 44 and 52 passengers, and 311 of this model plane were produced. Finally Convair would create a Convair 440, which had small modifications, including much better soundproofing than the previous models. Convair would experience a little bit of competition from the Martin 2-0-2 and Martin 4-0-4, but in general Convair was able to control this market, as the 2-0-2 had safety concerns and was unpressurized, and the 4-0-4 only sold around 100 units. [9]

The United States was dominant in this industry for several reasons, including a large domestic market for these planes. The market would also work in the United States favor as the American companies began to build pressurized airliners. During the postwar years engines became much larger and more powerful, and safety features such as deicing, navigation, and weather were added to the planes. Lastly, the planes produced in the United States were more comfortable and had superior flight decks than those produced in Europe. [9]

France

In the postwar years France developed a few significant airliners, some of these being planes that could land on water, part of the reason that the French companies were so focused on these flying boats is that in 1936 the French Air Ministry requested transatlantic flying boats that could hold at least 40 passengers. Only one model from this request would ever be put into service. The first set of these were three Latécoère 631's that Air France purchased and put into service in July 1947. However, two of these planes crashed, and the third plane was soon removed because of safety concerns. There would later be a SNCASE SE.161 Languedoc build, which was a much more successful plane, and over 100 of these were built, with 40 of them being placed into service through Air-France. [9] The French also developed the Breguet 763 Deux Ponts, which first flew in February 1949. This was a double-decker transport airliner that would end up being used for both people and cargo. This four-engine airliner would end up being used to hold large amounts of cargo or 97 passengers. After a long silence, France then created the Caravelle, the world's first short-to-midrange jet airliner. Subsequent French efforts were part of the Airbus pan-European initiative.

USSR

Soon after the war most of the Soviet fleet of airliners consisted of DC-3s or the Lisunov Li-2. These planes were in desperate need of replacement, and in 1946 the Ilyushin Il-12 made its first flight. The Il-12 was very similar in design to American Convair 240, except was unpressurized. In 1953 the Ilyushin Il-14 would make its first flight, and this version was equipped with much more powerful engines. The main contribution that the Soviets made in regards to airliners was the Antonov An-2. This plane is a biplane, unlike most of the other airliners, and sold more units than any other transport plane. [9]

Other Languages
العربية: طائرة رحلات
bosanski: Putnički avion
čeština: Dopravní letoun
français: Avion de ligne
한국어: 여객기
Bahasa Indonesia: Pesawat penumpang sipil
íslenska: Farþegaflugvél
italiano: Aereo di linea
lietuvių: Oro laineris
日本語: 旅客機
norsk nynorsk: Passasjerfly
português: Avião comercial
Scots: Airliner
Simple English: Airliner
slovenčina: Dopravné lietadlo
slovenščina: Potniško letalo
srpskohrvatski / српскохрватски: Putnički avion
svenska: Trafikflyg
Türkçe: Yolcu uçağı
Tiếng Việt: Máy bay dân dụng
中文: 民航飛機