July 1949. (Flight 1949/07/28)
July 1949. (Flight 1949/07/28)
1952. 106 Comet Airliner.
Note: This is a sub-section of De Havilland: Aircraft.
The De Havilland DH 106 Comet was the world's first production commercial jetliner. Developed and manufactured by De Havilland at its Hatfield Aerodrome, Hertfordshire, United Kingdom headquarters, the Comet 1 prototype first flew on 27 July 1949. 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.
- The square-windowed Comet 1 was the first model produced, a total of 12 aircraft in service and test. Following closely the design features of the two prototypes, the only noticeable change was the adoption of four-wheel bogie main undercarriage units, replacing the single main wheels. Four Ghost 50 Mk 1 engines were fitted (later replaced by more powerful Ghost DGT3 series engines). The span was 115 ft (35.05 m), and overall length 93 ft (28.35 m); the maximum takeoff weight was over 105,000 lb (47.628 kg) and over 40 passengers could be carried.
- The Comet 2 had a slightly larger wing, higher fuel capacity and more powerful Rolls-Royce Avon engines, which all improved the aircraft's range and performance; its fuselage was 3 ft 1 in (0.94 m) longer than the Comet 1's. Design changes had been made to make the aircraft more suitable for transatlantic operations. Following the Comet 1 disasters, these models were rebuilt with heavier gauge skin and rounded windows, and the Avon engines featuring larger air intakes and outward-curving jet tailpipes.A total of 12 of the 44-seat Comet 2s were ordered by BOAC for the South Atlantic route. The first production aircraft (G-AMXA) flew on 27 August 1953.
- The Comet 3, which flew for the first time on 19 July 1954, was a Comet 2 lengthened by 15 ft 5 in (4.70 m) and powered by Avon M502 engines developing 10,000 lbf (44 kN). The variant added wing pinion tanks, and offered greater capacity and range. The Comet 3 was destined to remain a development series since it did not incorporate the fuselage-strengthening modifications of the later series aircraft, and was not able to be fully pressurised.
- The Comet 4 was a further improvement on the stretched Comet 3 with even greater fuel capacity. The design had progressed significantly from the original Comet 1, growing by 18 ft 6 in (5.64 m) and typically seating 74 to 81 passengers compared to the Comet 1's 36 to 44 (119 passengers could be accommodated in a special charter seating package in the later 4C series). The Comet 4 was considered the definitive series, having a longer range, higher cruising speed and higher maximum takeoff weight. These improvements were possible largely because of Avon engines with twice the thrust of the Comet 1's Ghosts. Deliveries to BOAC began on 30 September 1958 with two 48-seat aircraft, which were used to initiate the first scheduled transatlantic services.
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