Video 018 showing de Havilland Comet Flypast Fast and Slow Open Day 6Jun59. de Havilland DH.106 Comet       The need for a jet-powered mail plane/airliner was identified by the famous Brabazon Committee that sat during wartime, tasked with identifying post-World War II British commercial aviation requirements.   This produced Specification IV, to which de Havilland initially responded in 1944.   With the end of the war in 1945, de Havilland was able to turn its full attention to the design of the Comet 1 passenger airliner, which first flew on 27 July 1949 piloted by John Cunningham.   During the intervening period the emphasis had shifted from mail carriage to passenger airliner.   At this stage the Comet was three to five years ahead of alternative American and Russian designs, embodying some leading-edge technology, including an all-metal stressed skin bonded using the redux metal-to-metal bonding method pioneered on earlier de Havilland designs, a much greater level of cabin pressurization, high-pressure refuelling and hydraulic-powered flight controls.   The Comet 1 was powered by four de Havilland Ghost MK50-1 turbojet engines built and blended into the wing root in pairs either side of the fuselage.   After an extensive flight test programme by prototypes, the first production standard Comet 1 was delivered to BOAC in January 1951.   Early examples were used on freight services to conduct trials and route proving until 2 May 1952, when BOAC operated the world's first fare-paying jet airliner service from London to Johannesburg (with stops).   Export orders were received for the Comet 1 (1A) from UTA, Air France, Canadian Pacific and the Royal Canadian Air Force, with potentially many more to follow.   On 2 May 1953, however, BOAC Comet 1 was the first of several to suffer a catastrophic failure when it crashed shortly after take-off from Calcutta.   As a result of subsequent seemingly inexplicable losses, the Comet was grounded.   The Air Ministry along with de Havilland then undertook a vast, expensive and exhaustive investigation, which included the use of pressurized Comet airframes on soak test.   This eventually resulted in the total failure of one airframe due to stress cracking around the cornering of a rectangular cabin window.   These investigations were of immense use to the entire aircraft industry, which was now able to counter stress cracking/cornering on pressurized jet transports by designing out rectangular apertures and surfaces.   Yet the loss of prestige, resource and confidence effectively eradicated Britain's lead in passenger aviation and wiped out the incipient Comet 2's commercial prospects - most of the 16 built were used for research or by the RAF as unpressurized transports.   Despite this, de Havilland proceeded to launch the stretched Comet 4, with revised airframe design and powered by four Rolls-Royce Avon engines.   It first flew on 27 April 1958, shortly ahead of the Boeing 707.   The launch customer was BOAC, which ordered 19, and two more variants were introduced - the further stretched/clipped-wing Comet 4B for shorter /European sectors and the Comet 4C which retained the 4B's stretch while reverting to the original Comet 4's wing with its distinctive fuel tanks.   Both BEA and Olympic Airways were customers for the Comet 4B, while the Comet 4 and 4C were exported in modest numbers to airlines such as Aerolineas Argentinas, Sudan Airways, Malaysian Airways and Kuwait Airways.   Seventy-six Comet 4 series airframes were built out of a total of 114 Comets of all marques.   The Comet 4 was no match for larger versions of the Boeing 707and DC-8.   Consequently it was retired relatively early by frontline operators, but it found a second career with charter operators BEA Airtours and Dan Air from the mid-1960s.   Dan Air purchased total of 48 second-hand Comet 4s of all variants and became the last regular operator when it acquired the RAF Transport Command's five Comet 4Cs in 1975.   Dan Air ceased Comet operations in 1980, but one example remained operational as a testbed with the RAE until 1997. de Havilland Dh.106 Comet 4: Crew 3; Powerplant: four Rolls-Royce Avon 524 turbojet engines each rated at 10,500lb; Performance: cruising speed 503mph at 25,000ft; Range 3,225 miles with maximum payload; Service ceiling 42,000ft.   Dimensions: wingspan 114ft 10in, length 111ft 6in, height 29ft 6in, wing area 2,121sqft.   Weight: 162,000lb maximum take-off weight.   Payload: up to 84 people in a mixed passenger class, or 119 five abreast in single-class charter layout. (Thanks to "The Encyclopedia of Aircraft" by Robert Jackson). There is no sound with this clip.   This clip runs for 30 secs. (Thanks to Wilf Zucht for original film.)