de havilland comet incidente

[39], Several of the Comet's avionics systems were new to civil aviation. The Feb 1959 OAG shows eight transatlantic Comets a week out of London with 10 BOAC Britannias and 11 DC-7Cs. It was the last leg of the new … [93] The Comet 1 and 1A had been criticised for a lack of "feel" in their controls,[95] and investigators suggested that this might have contributed to the pilot's alleged over-stressing of the aircraft;[96] Comet chief test pilot John Cunningham contended, however, that the jetliner flew smoothly and was highly responsive in a manner consistent with other de Havilland aircraft. [64] Upgraded Avon engines were introduced on the Comet 3,[64] and the Avon-powered Comet 4 was highly praised for its takeoff performance from high altitude locations such as Mexico City. In April, another Comet, this one operated by South African Airways, came apart in midair, again over the Mediterranean. All production Comet 2s were also modified to alleviate the fatigue problems (most of these served with the RAF as the Comet C2), while a programme to produce a Comet 2 with more powerful Avons was delayed. [41], The Comet had a total of four hydraulic systems, two primaries, one secondary, and a final emergency system for basic functions such as lowering the undercarriage. Kodera, Craig, Mike Machat and Jon Proctor. [35][N 11] For passengers used to propeller-driven airliners, smooth and quiet jet flight was a novel experience. [90], The Comet's second fatal accident occurred on 2 May 1953, when BOAC Flight 783, a Comet 1, registered G-ALYV, crashed in a severe thundersquall six minutes after taking off from Calcutta-Dum Dum (now Netaji Subhash Chandra Bose International Airport), India,[91] killing all 43 on board. [51] The chemical bonding process was accomplished using a new adhesive, Redux, which was liberally used in the construction of the wings and the fuselage of the Comet; it also had the advantage of simplifying the manufacturing process. [82], Since retirement, three early-generation Comet airframes have survived in museum collections. [64] Comet commercial flights would not resume until 1958.[127]. [97] Aviation author Bill Withuhn concluded that the Comet had pushed "'the state-of-the-art' beyond its limits. Era motorizzato da quattro turbogetto Rolls-Royce Avon 524. 106 Comet 4C con numero di registrazione SU-ALD, numero di serie 6441 e costruito nel 1960. [9] First-phase development of the DH.106 focused on short and intermediate range mailplanes with a small passenger compartment and as few as six seats, before being redefined as a long-range airliner with a capacity of 24 seats. [188] However, this plan did not go ahead and the airframe was scrapped in 2013. (Both flights were taking off from Rome.) [185] While painted in BOAC colours, it never flew for the airline, having been first delivered to Air France and then to the Ministry of Supply after conversion to 1XB standard;[185] this aircraft also served with the RAF as XM823. The Comet was grounded, this time permanently, and its certification was revoked. [102], Media attention centred on potential sabotage,[88] while other speculation ranged from clear-air turbulence to an explosion of vapour in an empty fuel tank. [10] A number of unorthodox configurations were considered, ranging from canard to tailless designs;[N 4] All were rejected. For the era, it offered a relatively quiet, comfortable passenger cabin and was commercially promising at its debut in 1952. Il 12 gennaio, il New York Times riferì che la BOAC aveva temporaneamente ritirato dal servizio tutti i suoi de Havilland Comet a causa dell'incidente, insieme alle due compagnie aeree francesi che utilizzavano i Comet, Air France e l'Union Aero Maritime des Transports. [30][60] Two hydrogen peroxide-powered de Havilland Sprite booster rockets were originally intended to be installed to boost takeoff under hot and high altitude conditions from airports such as Khartoum and Nairobi. "[170], The Comet 5 was proposed as an improvement over previous models, including a wider fuselage with five-abreast seating, a wing with greater sweep and podded Rolls-Royce Conway engines. [126] Remaining Comet 1s and 1As were either scrapped or modified with oval windows and rip-stop doublers. [15], As the Comet represented a new category of passenger aircraft, more rigorous testing was a development priority. Although the fuselage failed after a number of cycles that represented three times the life of G-ALYP at the time of the accident, it was still much earlier than expected. [98][99] With no witnesses to the disaster and only partial radio transmissions as incomplete evidence, no obvious reason for the crash could be deduced. [110] The fuselage escape hatch cut-outs retained their rectangular shape. Hill, Malcolm L. "de Havilland's Comet: Pushing the Boundaries.". [14], In September 1946, prior to the completion of the DH 108s, BOAC requests necessitated a redesign of the DH.106 from its previous 24-seat configuration to a larger 36-seat version. [190] A Comet 4B (G-APYD) is stored in a facility at the Science Museum at Wroughton in Wiltshire, England. This wreckage was from the starboard side of the cabin just above the three front windows. [119] The punch rivet construction technique employed in the Comet's design had exacerbated its structural fatigue problems;[98] the aircraft's windows had been engineered to be glued and riveted, but had been punch riveted only. Green, William and Gordon Swanborough, eds. Simons, Graham M. "Comet! ", From 1944 to 1946, the design group prepared submissions on a three-engined twin-boom design, a three-engined canard design with engines mounted in the rear, and a tailless design that featured a. [137] The Comet 4C had the Comet 4B's longer fuselage and the longer wings and extra fuel tanks of the original Comet 4, which gave it a longer range than the 4B. DH106 Comet simulator at The de Havilland Museum, London Colney, UK. Atkinson, R. J., W. J. Winkworth and G. M. Norris. [14][19][20] The entire forward fuselage section was tested for metal fatigue by repeatedly pressurising to 2.75 pounds per square inch (19.0 kPa) overpressure and depressurising through more than 16,000 cycles, equivalent to about 40,000 hours of airline service. Witnesses observed the wingless Comet on fire plunging into the village of Jagalgori,[92] leading investigators to suspect structural failure. Il velivolo coinvolto nell'incidente era un De Havilland Comet DH. Armour had to be placed around the engine cells to contain debris from any serious engine failures; also, placing the engines inside the wing required a more complicated wing structure. [19] The prototype's maiden flight, out of Hatfield Aerodrome, took place on 27 July 1949 and lasted 31 minutes. [83][84] Qantas was interested in the Comet 1 but concluded that a version with more range and better takeoff performance was needed for the London to Canberra route. [112] The windows' square shape caused stress concentration by generating levels of stress two or three times greater than across the rest of the fuselage. [14] Sprite fittings were retained on production aircraft. The Sud-Est SE 530/532/535 Mistral (FB 53) was a single-seat fighter-bomber version of the de Havilland Vampire jet fighter, used by. Il Comet era un quadrigetto completamente metallico ad ala bassa a freccia di 20 °, ottenuta prevalentemente dalla rastremazione in pianta; l'ala era costituita da tre longheroni che univano le semiali transitando nella parte inferiore della fusoliera, sotto il piano del pavimento. [191] Comet 4Cs are exhibited at the Flugausstellung Peter Junior at Hermeskeil, Germany (G-BDIW),[192] the Museum of Flight Restoration Center near Everett, Washington (N888WA),[177] and the National Museum of Flight near Edinburgh, Scotland (G-BDIX). Jones, Barry. [140] In 1960, as part of a government-backed consolidation of the British aerospace industry, de Havilland itself was acquired by Hawker Siddeley, within which it became a wholly owned division. La de Havilland Aircraft Company fu un'azienda britannica operante nel campo dell'aeronautica fondata da Geoffrey de Havilland nel settembre del 1920, dopo il fallimento dell'Aircraft Manufacturing Company, nota anche come Airco.La de Havilland Aircraft Company fu un'azienda molto importante, produttrice dei primi jet per passeggeri ed altri velivoli innovativi. ��wy���&��l�� �qi,�Z��`g �-�&��~ʼQ�p�$�VMn�~����;u��v�?��Q�R���d"w_U��jYD.��8cd��Mc���x\�!x��A)F�XZ�TY��iTg2�l-��P��7�5$�Vz�%�U]�ܚ�]c�R2�2�V�r�+�$Ѫ�Q�.��8X��tU��vހ�2��0����\U�ܐ���MvЧY���V�ݥ�U�'|��da0"�ӣ���I�I��k�m. (Zoggavia) 8 April 1954: Suid-Afrikaanse Lugdiens (South African Airways) Flight 201, a chartered British Overseas Airways Corporation de Havilland DH.106 Comet 1, departed Rome at 1832 UTC, bound for Cairo. [141], In the 1960s orders declined, with a total of 76 Comet 4s being delivered from 1958 to 1964. However, within a year of entering airline service, problems started to emerge, with three Comets lost within twelve months in highly publicised accidents, after suffering catastrophic in-flight break-ups. On whether we grasp this opportunity and so establish firmly an industry of the utmost strategic and economic importance, our future as a great nation may depend. [155], The Comet was involved in 26 hull-loss accidents, including 13 fatal crashes which resulted in 426 fatalities. [27] Both prototypes could be externally distinguished from later Comets by the large single-wheeled main landing gear, which was replaced on production models starting with G-ALYP by four-wheeled bogies. [109], On 8 April 1954, Comet G-ALYY ("Yoke Yoke"), on charter to South African Airways, was on a leg from Rome to Cairo (of a longer route, SA Flight 201 from London to Johannesburg), when it crashed in the Mediterranean near Naples with the loss of all 21 passengers and crew on board. 10 0 obj <> endobj Depending on weight and temperature, cruise fuel consumption was 6 to 10 kg per nautical mile, the higher figure being at the lower altitude needed at high weight. [105] The first pieces of wreckage were discovered on 12 February 1954[106] and the search continued until September 1954, by which time 70 percent by weight of the main structure, 80 percent of the power section, and 50 percent of the aircraft's systems and equipment had been recovered. Following the accidents, the de Havilland Comet was understandably withdrawn from service, while engineers and technicians worked on its structural issues. [102] The prestigious nature of the Comet project, particularly for the British aerospace industry, and the financial impact of the aircraft's grounding on BOAC's operations, both served to pressure the inquiry to end without further investigation. Hall's team began considering fatigue as the most likely cause of both accidents, and initiated further research into measurable strain on the aircraft's skin. [135] Olympic Airways was the only other customer to order the type. [182] Pilot error was blamed for the type's first fatal accident, which occurred during takeoff at Karachi, Pakistan, on 3 March 1953 and involved a Canadian Pacific Airlines Comet 1A. [146] Cunningham likened the Comet to the later Concorde, and added that he had assumed that the aircraft would change aviation, which it subsequently did. [19] However, tracing fuselage failure points proved difficult with this method,[19] and de Havilland ultimately switched to conducting structural tests with a water tank that could be safely configured to increase pressures gradually. [162], 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). [49], Diverse geographic destinations and cabin pressurisation alike on the Comet demanded the use of a high proportion of alloys, plastics, and other materials new to civil aviation across the aircraft in order to meet certification requirements. The wing was drastically redesigned from a 40˚ sweep. [184] Other fatal Comet 4 accidents include a British European Airways crash in Ankara, Turkey, following instrument failure on 21 December 1961, United Arab Airlines Flight 869 during inclement weather near Bombay, India, on 28 July 1963, and the terrorist bombing of Cyprus Airways Flight 284 off the Turkish coast on 12 October 1967. We were in 1959 on 27th of August when a Comet 4 (LV-AHP) - operated by Aerolineas Argentinas - during a final approach to Asuncion airport (Paraguay ) encountered marginal weather conditions with … This was because in 1945 no turbojet engine manufacturer in the world was drawing up a design specification for an engine with the thrust and specific fuel consumption, that could power an aircraft at the proposed cruising altitude (40 thousand feet), speed, and transatlantic range as was called for by the Type 106. Efficient regional operations. A de Havilland DH-106 Comet 1 passenger plane, registered G-ALYP, was destroyed in an accident 16 km S off Elba, Italy. As a result, the Comet was extensively redesigned, with oval windows, structural reinforcements and other changes. The MoT subsequently backed BOAC's order of Conway-powered Boeing 707s. Chief designer Bishop chose the Comet's embedded-engine configuration because it avoided the drag of podded engines and allowed for a smaller fin and rudder, since the hazards of asymmetric thrust were reduced. [64] The square windows of the Comet 1 were replaced by the oval versions used on the Comet 2, which first flew in 1953, and the skin thickness was increased slightly. [85], On 26 October 1952, the Comet suffered its first hull loss when a BOAC flight departing Rome's Ciampino airport failed to become airborne and ran into rough ground at the end of the runway. It was later determined that the Comet's wing profile experienced a loss of lift at a high angle of attack, and its engine inlets also suffered a lack of pressure recovery in the same conditions. [54][55], The Comet was powered by two pairs of turbojet engines buried in the wings close to the fuselage. The DeHavilland Comet Crash. The Comet 4 first flew on 27 April 1958 and received its Certificate of Airworthiness on 24 September 1958; the first was delivered to BOAC the next day. La BOAC confermò che avrebbe utilizzato velivoli alternativi per ridurre al minimo l'interruzione dei servizi. [69] While BOAC gained publicity as the first to provide transatlantic jet service, by the end of the month rival Pan American World Airways was flying the Boeing 707 on the same route,[131] and in 1960 the Douglas DC-8 as well. Extra payload capacity. [116] The fuselage frames did not have sufficient strength to prevent the crack propagating. [40] Additionally, a large number of the control surfaces, such as the elevators, were equipped with a complex gearing system as a safeguard against accidentally over-stressing the surfaces or airframe at higher speed ranges. Cunningham: "[the Comet] flew extremely smoothly and responded to the controls in the best way de Havilland aircraft usually did.". [98] With the recovery of large sections of G-ALYP from the Elba crash and BOAC's donation of an identical airframe, G-ALYU, for further examination, an extensive "water torture" test eventually provided conclusive results. [69][70][71] The final Comet from BOAC's initial order, registered G-ALYZ, began flying in September 1952 and carried cargo along South American routes while simulating passenger schedules. ", "De Havilland Comet 4B airliner, serial no 6438, 1960. This time, the entire fuselage was tested in a dedicated water tank that was built specifically at Farnborough to accommodate its full length. His licence was issued on 20 August 1969 and was valid until 21 August 1970. The de Havilland DH.106 Comet was the world's first commercial jet airliner. [62] Comet 1s subsequently received more powerful 5,700 lbf (25 kN) Ghost DGT3 series engines. [11][149] While the Comet's buried engines were used on some other early jet airliners, such as the Tupolev Tu-104,[150] later aircraft, such as the Boeing 707 and Douglas DC-8, would differ by employing podded engines held on pylons beneath the wings. [26] Australian airline Qantas also sent its own technical experts to observe the performance of the prototypes, seeking to quell internal uncertainty about its prospective Comet purchase. The DeHavilland Comet was the first production commercial jet airliner that went into service in 1952. With the discovery of the structural problems of the early series, all remaining Comets were withdrawn from service, while de Havilland launched a major effort to build a new version that would be both larger and stronger. Queen Elizabeth, the Queen Mother and Princess Margaret were guests on a special flight of the Comet on 30 June 1953 hosted by Sir Geoffrey and Lady de Havilland. De Havilland DH.106 Comet 1 G-ALYY, 1953. [5] One of its recommendations was for the development and production of a pressurised, transatlantic mailplane that could carry non-stop, one long ton (1.0 t) of payload at a cruising speed of 400 mph (640 km/h). �F`U The Comet, registered G-ALYY, was under the command of Captain Wilhelm K. Mostert, with First Officer Barent J. Grove, Navigator Albert E. Sissing, Radio Officer Bertram E. Webstock, and Flight … The Comet Story. Operator: Registration: G-ALYZ. [157] 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. ", "ASN Aircraft accident de Havilland DH-106 Comet 4 G-APDN Sierra del Montseny", "de Havilland DH106 Comet 1A – de Havilland Aircraft Museum", "Gate Guardian Comet C2 Sagittarius – XK699 – RAF Lyneham. [136] The last Comet 4 variant, the Comet 4C, first flew on 31 October 1959 and entered service with Mexicana in 1960. [63], 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;[157] its fuselage was 3 ft 1 in (0.94 m) longer than the Comet 1's. The earliest production aircraft designated G-ALYP was loaned to the British Overseas Airways Company and inaugurated the first scheduled overseas flight from London to Johannesburg with fare-paying customers on-board. The de Havilland Ghost (originally Halford H-2) was the de Havilland Engine Company's second turbojet engine design to enter production and the world's first gas turbine engine to enter airline service.A scaled-up development of the Goblin, the Ghost powered the de Havilland Venom, de Havilland Comet … w�aes��^_'Zj��N�r�iUjcKS�1/M}l�;��y]��d~9%��k2+�FM�6[��� After design modifications were implemented, Comet services resumed in 1958. The Comet, registered G-ALYY, was under the command of Captain Wilhelm K. Mostert, with First Officer Barent J. Grove, Navigator … Categoría:Accidentes e incidentes de de Havilland Comet. [75], In 1953 the Comet appeared to have achieved success for de Havilland. [180], In military service the United Kingdom's Royal Air Force was the largest operator, with the 51 Squadron (1958–1975; Comet C2, 2R), 192 Squadron (1957–1958; Comet C2, 2R), 216 Squadron (1956–1975; Comet C2 and C4), and the Royal Aircraft Establishment using the aircraft. Developed and manufactured by de Havilland at its Hatfield Aerodrome in Hertfordshire, United Kingdom, the Comet 1 prototype first flew in 1949. There were eight passengers and eight crew members on board. The cargo hold had its doors located directly underneath the aircraft, so each item of baggage or cargo had to be loaded vertically upwards from the top of the baggage truck, then slid along the hold floor to be stacked inside. The inquiries into the accidents that plagued the Comet 1 were perhaps some of the most extensive and revolutionary that have ever taken place, establishing precedents in accident investigation; many of the deep-sea salvage and aircraft reconstruction techniques employed have remained in use within the aviation industry. ", "De Havilland Comet 4C G-BDIX Interior View Scottish Museum of Flight. Desenvolvido e fabricado por de Havilland na súa sede de Hatfield, Hertfordshire, no Reino Unido, realizou o seu primeiro voo en 1949 e foi un fito no deseño aeronáutico. ", "Report of the Public Inquiry into the causes and circumstances of the accident which occurred on the 10 January 1954, to the Comet aircraft G-ALYP, Part IX (d). The American jets were larger, faster, longer-ranged, and more cost-effective than the Comet. Entering service in 1969, five Nimrod variants were produced. On 10 January 1954, 20 minutes after taking off from Ciampino, the first production Comet, G-ALYP, broke up in mid-air while operating BOAC Flight 781 and crashed into the Mediterranean off the Italian island of Elba with the loss of all 35 on board. British South American Airways merged with BOAC in 1949. [164] The variant added wing pinion tanks, and offered greater capacity and range. 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). ", "Metal to Metal Bonding – For Aircraft Structures: Claims of the Redux Process. [53], Operationally, the design of the cargo holds led to considerable difficulty for the ground crew, especially baggage handlers at the airports. [50] The Comet's high cabin pressure and fast operating speeds were unprecedented in commercial aviation, making its fuselage design an experimental process. [6][12] During flight tests the DH 108 gained a reputation for being accident-prone and unstable, leading de Havilland and BOAC to gravitate to conventional configurations and, necessarily, designs with less technical risk. The Ministry of Supply was, however, interested in the most radical of the proposed designs, and ordered two experimental tailless DH 108s[N 5] to serve as proof of concept aircraft for testing swept-wing configurations in both low-speed and high-speed flight. To this end we propose to use thicker gauge materials in the pressure cabin area and to strengthen and redesign windows and cut outs and so lower the general stress to a level at which local stress concentrations either at rivets and bolt holes or as such may occur by reason of cracks caused accidentally during manufacture or subsequently, will not constitute a danger. For VIP transport, the seating and accommodations were altered while provisions for carrying medical equipment including iron lungs were incorporated. [169] A Comet 4C (SA-R-7) was ordered by Saudi Arabian Airlines with eventual disposition to the Saudi Royal Flight for the exclusive use of King Saud bin Abdul Aziz. [147][148], Aeronautical engineering firms were quick to respond to the Comet's commercial advantages and technical flaws alike; other aircraft manufacturers learned from, and profited by, the hard-earned lessons embodied by de Havilland's Comet. [38] The navigator occupied a dedicated station with a table across from the flight engineer. [21], The first prototype DH.106 Comet (carrying Class B markings G-5-1) was completed in 1949, and was initially used to conduct ground tests and brief early flights. It featured an aerodynamically clean design with four de Havilland Ghost turbojet engines buried in the wing roots, a pressurised cabin, and large square windows. The other Comet 3 airframe was not completed to production standard and was used primarily for ground-based structural and technology testing during development of the similarly sized Comet 4.

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