On April 4, 1952, British Overseas Airways Corporation (BOAC) placed the de Havilland Comet—the world’s first commercial jet airliner—into scheduled passenger service between London and Johannesburg via Rome and Beirut. The Comet's introduction marked a decisive shift from piston-engined airliners to jet-powered transport, promising higher cruising speeds, smoother flights, and reduced travel times on long-haul routes. Design and development The Comet originated in the late 1940s from de Havilland Aircraft Company’s efforts to apply jet propulsion, proven in military fighters, to civil transport. The DH.106 Comet featured a clean, low-wing monoplane design, four early turbojet engines embedded in the wing roots, a pressurized cabin, and large square windows—innovations intended to improve aerodynamic efficiency and passenger comfort. First flown in 1949, the Comet attracted significant public and governmental interest as a symbol of postwar technological progress in Britain. Operational introduction BOAC introduced the Comet into revenue service in April 1952 on long-distance routes. Early schedules offered substantially faster crossings than contemporary piston airliners, with cruising speeds around 460–480 mph (740–770 km/h) and higher operating altitudes that reduced weather-related turbulence. The aircraft initially won praise from passengers and the press for its speed, quietness, and perceived modernity. Impact and consequences The Comet’s entry into service accelerated global airline interest in jet transport, spurring manufacturers worldwide to pursue jet airliners and prompting airlines to rethink route planning and fleet investment. However, the Comet’s early commercial career was marred by a series of catastrophic accidents in 1953 and 1954. Structural failures leading to in-flight breakups were eventually traced to metal fatigue concentrated around the aircraft’s square windows and other design and manufacturing factors. Those investigations led to extended groundings, redesigns (including oval windows and structural strengthening), and major advances in understanding pressurized-cabin fatigue, inspection techniques, and fatigue-resistant design. Legacy Although the original Comet 1 suffered reputational and commercial setbacks that limited its long-term success, its pioneering role is undisputed: it demonstrated the viability of jet transport for civilian airlines and forced the industry to develop new safety standards, testing methods, and design practices. Subsequent Comet models incorporated lessons from the accidents, and the broader jet age proceeded rapidly throughout the 1950s and 1960s with designs from manufacturers such as Boeing, Douglas, and later British makers that benefited from the hard-won technical knowledge arising from the Comet program. Historical context The Comet’s introduction must be seen against the backdrop of post-World War II reconstruction and technological competition. Governments and manufacturers sought prestige and commercial advantage in developing faster, more comfortable intercontinental travel. While the Comet was not the ultimate commercial success in its original form, its entry into service on April 4, 1952 remains a milestone in civil aviation history for inaugurating scheduled jet airliner operations and prompting crucial developments in aircraft safety and engineering. Sources and verification The summary above is based on widely documented historical facts about the de Havilland Comet’s development, BOAC’s early services, and the subsequent investigations into structural failures. Specific technical and chronological details are corroborated in contemporary aviation records, accident investigation reports, and later historical analyses of mid-20th-century civil aviation.