The first airliners were mostly leftover bombers with seats bolted in
When the First World War ended, Europe had a glut of big military aircraft and no war for them. Builders stripped out the bomb gear, added cabins and started flying paying passengers. Within months there was a scheduled international service between London and Paris, and the modern airline business had begun.
The idea had already been tested. In 1913 Igor Sikorsky built the first large multi-engined aeroplane, and its successor, the Ilya Muromets, offered dual controls, a heated and lit cabin and even a lavatory. It took 16 passengers aloft in February 1914, but the war turned it into a bomber instead of an airliner.
In 1919 conversions arrived in a rush. The French Farman F.60 Goliath, designed as a long-range heavy bomber, was refitted to carry up to 14 seated passengers, and one flew a dozen people across the Channel to RAF Kenley without permission to land. Vickers turned its Vimy bomber into the Vimy Commercial with a wider plywood fuselage. The Airco DH.16 squeezed four passengers into an enclosed cabin while the pilot sat outside in an open cockpit, and on 25 August 1919 Aircraft Transport and Travel used it to launch the first scheduled international airline service. That same year Germany's Junkers F.13 became the first all-metal transport aircraft.
Operators soon found that small cabins did not pay, and by 1921 designers such as de Havilland were chasing capacity with ten-seat machines. In America the Ford Trimotor, built from 1925 to 1933, helped popularise paved runways, passenger terminals, hangars and radio navigation.
The next leap came with metal monoplanes in the 1930s. The Douglas DC-3, introduced in 1935 with room for 21 to 32 passengers, was mass-produced for the Second World War, then sold off as surplus, and became one of the first airliners to make money without postal or government subsidies. Over the oceans, flying boats ruled, since land planes of that size would have needed impractically long runs to take off. One Boeing 314 became the first commercial aircraft to fly around the world, over December 1941 and January 1942.
Source: Airliner
