Comet – The First Jet Airliner Sir Geoffrey de Havilland conceived the idea of the DH106 'Comet' in 1943 and design work began in September 1946. The prototype first flew on 27 July 1949.

The world's first commercial jet airliner was the de Havilland DH.106 Comet, which was developed and manufactured in the United Kingdom. It made its inaugural flight in 1949 and entered regular commercial service with British Overseas Airways Corporation (BOAC) on May 2, 1952. The Comet was a marvel of post-war engineering, featuring four de Havilland Ghost turbojet engines buried in the wing roots, a pressurized cabin, and large square windows that offered passengers a smooth, quiet, and fast journey far above the weather that hampered piston-engine planes. At the time, it cut travel times in half and represented the dawn of the "Jet Age." However, the Comet's early success was tragically overshadowed by a series of catastrophic mid-air disintegrations in 1954. Investigations revealed that the square windows created stress concentrations that led to metal fatigue and explosive decompression. While the Comet was later redesigned with oval windows (the Comet 4), the delays allowed the American-made Boeing 707 and Douglas DC-8 to dominate the market. Despite its troubled start, the Comet pioneered the pressurized cabin technology and jet engine integration that are standard in every commercial aircraft flying today.