Accidents et Incidents aériens
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Jeannot
Inscrit le 02/10/2007 |
# 12 septembre 2008 13:26 | |
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Mais cela ne doit pas coûter deux sous. (Message édité par Jeannot le 12/09/2008 13h26) |
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alain57
Inscrit le 08/03/2008 |
# 12 septembre 2008 14:59 | |
| le moteur déposé doit etre réparé et ensuite monté sur un autre avion....(echange standart) reste a savoir qui paye ...!!! la compagnie ou GE, ou les deux..???? | ||
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Beochien
Inscrit le 13/02/2007 |
# 12 septembre 2008 17:51 | |
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Je reste émerveillé par A.net ! Ils ont des espions partout ceux là ! Quelle couverture !! Un assistant à Gander parle d'un PB Turbine ... Chez A.net, post 22 ! Pas moyen pour GE de cacher sa (Ses) misère avec les GE 90-115 !à Chicago (ANA) ou à Gander (Qatar) Et même si AF ferme bien les portes de ses MRO pour les trombinoscoper ... on finit par savoir !  -------------------------- L'info A.net est revenue sur Crash, que publie aussi Romandie.com, qui renvoie sur crash d'ailleurs ! Lien Crash, en Fr ! (Prudents, et conditionnels, normal !) http://www.crash-aerien.com/www/news/ar ... mp;check=0 Apparemment un Boeing 777-300 ER de la compagnie Qatar Airways effectuant le vol QR52 entre IAD et DOH Samedi 6 Septembre , se serait dérouté vers l'aéroport de Gander (CAN) à la suite d'un problème sur l'un de ses GE-90 et après avoir délesté une partie de son carburant .. L'incident semble n'avoir été évoqué dans aucun média et seuls les témoignages de passagers nous permettent de le signaler ici . Un Airbus A330 a été envoyé sur place pour ramener les passagers à destination de LHR ... Le vol est depuis assuré par un A340-600 ... (C'est plus sur  )A suivre . Rédacteur : Giou 31 ----------------------------- Bon chez A.net, certainsprétendent (A vérifier) que c'est un avion livré récemment ! Il n'aura pas trop usé du thrust bump celui là pourtant ! J'ajoute, que tout cela tends quand même à prouver que les PB GE 90-115 ne sont vraiment pas tous connus ! Sans les Pax, qui ont témoigné vers A.net, l'incident passait inaperçu ! Combien d'autres sont passés à travers ?? AF face la plus visible de l'iceberg ?? JPRS Paris (Message édité par Beochien le 12/09/2008 17h56) _________________ JPRS |
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sevrien
Inscrit le 08/08/2006 |
# 12 septembre 2008 18:00 | |
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Livraison une semaine avant l'incident ! J'ai cité l'affaire ci-dessus ! Cela semble être vrai ! Voir post ci-dessus, aujourd'hui, 12 /09 /2008 à 01h00.  |
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elmer
Inscrit le 27/09/2005 |
# 12 septembre 2008 18:01 | |
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Le coup du vol assuré par un A340-600, il ne faut pas y voir autre chose qu'une question de disponibilité. Qatar n'a pour l'instant que 3 777-300ER dans sa flotte. C'est exactement la même chose qu'un A380 de SIA remplacé temporairement par un 747-400 en cas de problème. |
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sevrien
Inscrit le 08/08/2006 |
# 12 septembre 2008 18:09 | |
| Oui ! Et Qatar n'a que 4 x A340-600HGW, n'est-ce pas ? | ||
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Beochien
Inscrit le 13/02/2007 |
# 12 septembre 2008 18:13 | |
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Eh Elmer ! Le droit à un peu d'humour à l'attention de Dupont ... qui à disparu depuis la grève chez Boeing, (en plus !! Pour Sévrien ! Oui j'avais vu ce matin, ici et chez A.net ! Mais ils ne sont pas trop sûrs!! _________________ JPRS |
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Beochien
Inscrit le 13/02/2007 |
# 12 septembre 2008 20:01 | |
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Bonsoir Tiens ! Pendant que je traine sur Crash ! Du 3/9, un pompage suivi de IFSD, sur un moteur de 777-200 D'UA Quels moteurs at'il celui là ?? Il y à une vingtaine de ommentaires derrière, principalement sur les trés courtes distances, sur lesquels sont utilisés ces gros oiseaux ! Intéressant à lire, et instructif, quel gâchis de consos ! A quand un MC de 300 pax !! ----------------------------- http://www.crash-aerien.com/www/news/ar ... mp;check=0 Las Vegas : déroutement 777-200 United suite arrêt moteur Las Vegas, 3/9/08 Un Boeing 777-200 de la compagnie américaine United Airlines, exploitant le vol UA1235 de Denver (Colorado-USA) à Los Angeles à bord de l'appareil immatriculé N216UA, a rencontré un pompage réacteur droit en vol, entrainant un arrêt automatique de celui ci. Les tentatives de remise en route en vol étant sans succès, l'équipage a déclaré une urgence et dérouté l'appareil vers Las Vegas (Nevada) ou l'appareil s'est posé sans encombre. Les passagers, reroutés sur un autre appareil de même type, ont atteint leur destination avec un retard de 7 heures ; voici le trajet de l'appareil, enregistré sur le site US de tracking bien connu -------------- JPRS Paris _________________ JPRS |
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sevrien
Inscrit le 08/08/2006 |
# 12 septembre 2008 20:05 | |
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Bonsoir ! Les B777-200 / -200ER d'UAL (j'ai bien compris : UAL ? ) sont à moteurs P&W Encore des histoires de pompage sur cette famille-là ? Wow ! |
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sevrien
Inscrit le 08/08/2006 |
# 12 septembre 2008 23:24 | |
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ETOPS, et tous ceux que ceci peut intéresser ... A ce stade, il semble préférable de reproduire cet article du "New Scientist", plutôt que de faire le copié-collé de Wikipedia que j'avais annoncé. Qui peut trouver une appréciation critique de la qualité de celle-ci, d'un rapport , d'une Commission d'Enquête d'accident d'avion, dans le sillage dudit rapport ? Je suis preneur ! Et il convient de réfléchir non seulement à ce qu'on doit au rapport de l'AAIB, sur l'accident B737 de Kegworth, en terme d'amélioration des avions et leur "in-built safety", mais , surtout, en terme de compréhension et justice envers les pilotes, notamment dans la formulation de la prose à leur encontre, dans le cadre d'un rapport d'Enqûete d'accident ! L'AAIB a beaucoup appris, ce qui explique le soin encore accru qu'il apporte à ses rédactions ! Et le temps qu'il se donne pour produire des rapports de qualité "irréprochable" ! Certains, et j'en suis, pensent que cet article du "New Scientist", et d'autres "papiers", dont nous avons cité des extraits dans d'autres posts sur l'accident B737 de Kegworth, ont contribué à de nombreuses améliorations de ce genre. Ce n'est qu'un avis personnel, mais largement partagé ; je n'ai pas dit "universellement partagé"! ------------- Lien : http://www.newscientist.com/article/mg1 ... fety-.html Human error in the air: The report on the M1 plane crash at Kegworth last year underlines the importance of the 'human factor' for safety. 17 November 1990 (Oui ce doc. est écrit en 1990 ! Bien en avance sur son temps ! ). From New Scientist Print Edition. British Midland Airways last month sacked the two pilots who were at the controls when a Boeing 737-400 smashed into the central reservation of the M1 motorway in January 1989. The crash killed 47 people. The report into the Kegworth disaster*, published last month, states that the pilots acted hastily and contrary to their training. Prose jugée inéquitable, et incohérente, ... par des experts qui ont décidé de faire une appréciation élégant et ferme contre les mauvaises formulations de l'AAIB de l'époque ! Attaquer les pilotes pour une question de degré dans la rapidité et / ou la hâte de leur réaction(s) ? ---------------- Yet it also points out mitigating circumstances for their actions, highlighting the fact that pilots operate in a complex and changing technical environment. A pilot's actions might be but one part of a set of circumstances that leads to an accident. Oui ! Cela peut bien être le cas ! ------------------ Some of the observations about the environment in which the two pilots were working also highlight a general area of concern for safety in modern aviation: the interface between pilot and machine and how it affects a pilot's performance. Frank Taylor, from the Cranfield College of Aeronautics, says: 'If a pilot makes an error, it's often because he or she has fallen into a hole that someone else has dug for him.' Il faut noter et retenir cette remarquie, bien appropriée dans le contexte de cet accident de Kegworth ! ----------------- Regulators and academics in the civil aviation world, though lagging considerably behind their military colleagues, are beginning to recognise the impact on safety of what are called 'human factors'. The relationship between machines and people is one aspect of the topic. On est en 1990 ! ----------------------- The evaluation of human factors in the cockpit is taking place against a background of increasing automation. The aviation world has dubbed those aircraft with highly automated flight decks 'glass cockpits'. The name comes from the glass TV screens that take the place of the devices which previously displayed flight infomation. The electronics and computer technology behind these glass screens mean that information can be presented in different ways. D'où, ... risques et dangers ! --------------------- It means, too, that machines can undertake tasks previously executed by pilots. Don Harris, from the applied psychology unit of the Cranfield College of Aeronautics, says: 'Pilots are changing from fliers to flight managers.' Oui ! Mais cette perception est avancée en 1990 ! ------------------ In many cases, the new technology leads to greater safety. For example, pilots wax lyrical about the benefits of what is termed the map mode of the horizontal situation indicator (HSI). This instrument combines the essential information about the plane's lateral and vertical position and speed with respect to the ground and superimposes the information on a map. In the early days of aviation, pilots would struggle with raw numbers and a separate map. Alistair Liddle, a pilot and head of the technical committees of the British Airline Pilots' Association, calls the instrument 'the best thing since sliced bread. It combines important information well, and pilots can easily assimilate what it says.' Très important ! ---------------- Yet not all displays are as well received by pilots. And the aviation world needs to query whether the new displays present information to the pilot as clearly as traditional instruments do. The Kegworth report emphasises this issue. Nous devons beaucoup au rapport final de l'enquête de l'accident B737 à Kegworth ! Mais, peut-être, plus encore à ceux qui en ont fait une appréciation critique ! ------------ Soon after take off, last January, the crew experienced 'moderate to severe vibration' and smelt smoke. The co-pilot monitored the instruments showing the health of the engines. When the commander asked which engine was causing a problem, the co-pilot started to say the left then switched to say the right engine. He obeyed the commander's order to throttle back the engine, and as he throttled back the right-hand engine, he clearly still thought that this was the faulty engine. Tragically, he was wrong. As the plane came in to land, the operating engine failed, and it was too late to restart the good engine. Voici une synthèse simple et précise ! Sans ironie aucune ! --------------------------- Analysis of the flight data recorder and of the wiring to the engine instruments in the cockpit proved that the instruments would have shown accurately which engine was suffering from unusual vibration. When questioned later, the co-pilot could not remember what he saw on the instruments that convinced him to switch off what turned out to be the wrong engine. A noter les remarques ci-dessus ! ! --------------------------------------------------- The report speculates that the hesitation between left and right could have been caused by genuine difficulty in reading the instruments. Oui ! -------------- The investigators point out that the pointer on the engine vibration monitor was far shorter than its electromechanical counterpart. Alternatively, the co-pilot may have have observed the instruments during a six-second period when, according to the flight data recorder, the instruments for the left hand engine showed 'relative stability'. Le détail a été bien analysé ! -------------------- In a later incident, a Dan Air crew who were flying a Boeing 737-400 experienced similar conditions of vibration and smoke. The commander identified the faulty engine correctly from readings on the engine instruments. But the pilot told investigators that all the engine instruments looked alike, and that it took time for him to be certain that he had identified the affected engine. Problème ! Pas créé par les pilotes ! ----------------------- Fortunately, he had the cautionary tale of Kegworth to guide him. Lessons learned ! ---------------------- One of the recommendations from the investigation into Kegworth is that the rules for certifying new instruments should be modified to include standard tests for assessing how well instruments relay information to the crew in both normal and abnormal conditions. The investigators recommend that airline pilots should be involved in the process - a view Liddle agrees with. Evidemment ! Comment est-ce que cela n'a pas été le cas ? Manque de bon sens ? ----------------------- Currently, test pilots and senior pilots, not the pilots flying routinely for airlines, are asked to assess the effectiveness of instruments. One former flying instructor says that test pilots are specialists at the top of their profession and that they cannot be expected to react in the same way as the airline pilots. Liddle, an airline pilot, says he has observed in simulator training that test pilots and senior instructors react very differentlyfrom the airline pilots. 'Perhaps airline pilots are more practical,' he says. Il ne faut pas "intellectualiser" le problème ! ----------------------------- Computer technology allows designers to call up on screen alternative instrument designs relatively easily. The time it takes an airline pilot to read information from the simulated instruments and the number of errors the pilot makes would provide objective data on the effectiveness of a particular design. And the tests need to take place when the pilot is under stress, not only during routine operations. Nous devons, effectivement, beaucoup au rapport de Kegworth ! -------------------------- The Kegworth report's criticism that the pilots acted contrary to their training is based on the fact that they acted hastily. C'est ceci qui est considéré inéquitable et incohérent ! ---------------- Yet the report points out that neither pilot had experienced a combination of high vibration and smoke in the cockpit, either in training........... Ceci n'est nullement la faute des pilotes ! ....or in operation. Ceci non plus ! ------------------------- The report says the combination of circumstances appears to have driven them to act quickly in response to what they perceived as a serious engine malfunction with an associated fire. Plutôt un point positif ! ------------------------- Neither pilot had practised fault diagnosis with information from those instruments. In fact, in the past, pilots often disregarded readings from vibration monitors because they believed them to be unreliable. After the Kegworth accident, the pilot, Captain Hunt, expressed this view. Les circonstances n'étaient pas bonnes ! C'est du passé, maintenant ! Les choses ont bien évolué ! ------------- However, advances in technology mean that monitors, such as those on the 737-400 are far more reliable, and the accident investigators recommended that pilots should be made aware of technical improvements that have turned what was a rarely used instrument into one of more significance. Un bon point du rapport ! Nous sommes en 1990 ! --------------------- The Civil Aviation Authority has accepted both this recommendation and another that advocates using simulators to teach pilots how to interpret information displayed by the vibration monitors. On s'étonne que ceci ne fût pas le cas à l'époque ! Où que ce soit ! --------------------------- The question of training and automation, though, is much broader. Currently, pilots tend to be taught to read what the instruments are saying, rather than how the system works. One aviation psychologist believes that this needs examining. Evidemment ! Mais ceci était un aspect 'contesté' par certains à l'époque ! Etonnant ! --------------------------------- Clearly, he says, pilots do not need to know how to program the machines, but they should know a bit about how they work. Comments heard on the flight deck include, 'I've never seen it do that before' or 'Why's it doing that?' Anyone who has operated a word processor must have said the same thing at some time. A pilot may not have time to work out why his system is throwing up unfamiliar signs. Evidemment ! Cela semble si évident ! ----------------------- The specific questions raised by the accident investigators are to be reviewed by the accident investigation and the air worthiness committees of the British Airline Pilots' Association, says Liddle. At the same time, Roger Green, head of psychology at the RAF's Institute of Aviation Medicine, is conducting a survey of pilots' views of automation. Green, who devised much of the syllabus for the CAA's new pilots' examination on human performance, is currently analysing responses from 1300 pilots. En 1990 ! Nous devons beaucoup à ce malheureux accident de Kegworthe ! Qui peut dire honnêtement que, à l'époque, ces aspects recevaient, partout dans le monde, une attention équivalente ? ------------------ A first glance at the responses shows that many pilots are well satisfied with automation, but that there are important reservations. Some of the older pilots worry that sophisticated technology can give young pilots a false impression of their flying abilities. When they return to an aircraft with more traditional technology, they have to unlearn bad habits. La remarque est, sans doute, valable ! -------------------- Other pilots note that when everything is going well during a flight, automation works well and reduces the pilot's workload. Oui ! Exactement ! --------------------- If a problem arises, automation can increase the workload at the worst possible time. Vrai, aussi ! ------------------------ At Kegworth, for example, the co-pilot had to reprogram the flight management system with new information about diverting to east Midlands Airport. It took two minutes to do this at a critical time in the flight. Oui ! Et il n'est pas dit que l'AAIB, à l'époque, ait suffisamment pris ceci en compte, en évaluant les réactions des pilotes ! ------------------------------- Crucial exchanges with air traffic control and attempts to reprogram the flight management system meant that the pilots never had time to complete a review of their decision and their response to it, although the Commander did initiate this. Ceci est factuel ! Ce n'est pas une 'excuse' ! ------------------------- Earl Wiener, from the University of Miami, has studied the benefits and hazards of cockpit automation. He believes that when new automated cockpits are certified, regulatory authorities should assess the workload during abnormal circumstances, not just when everything is going well. C'est évident ! Il fallait un certain courage pour le dire et l'écrire en 1990 ! ---------------------------- Yet another concern expressed by British pilots centres on what they term 'mode awareness'. 'They may think,' says Green, 'that the aircraft is programmed to level out at a particular altitude, but it isn't, so they overshoot, and may have a near air miss.' Réactions des pilotes fançais, par exemple ? ------------------------- All of these concerns demonstrate that a pilot can be responding to an unusual situation in what they perceive to be the optimum way. Yet, in the changing high-technology environment, they may be tragically wrong. Il est courageux de dire ceci, surtout quand on sait qu'une bande de "monothinkers" vont le rejeter ! On voit bien qu'il y a ceux qui vivent de leurs certitudes, sans se poser des questions, ... les bonnes questions ! ------------------------ Perhaps an instrument they disregarded as unreliable has become more reliable; perhaps some combination of design and lack of training contributes to wrong decisions. Oui ! ------------------- At a meeting in London this week, Wiener told delegates at a conference on safety in the air and at sea that technology and safety must be placed in the broad context of the environment that a system works in. He warns: 'There is a tendency to blame accidents solely on the last person in the chain of events, usually the captain. Certains devraient réfléchir à cette phrase pleine de bon sens ! ------------------------------- Désolé pour la longueur de ce qui précède ! Mais je suis prêt à parier que beaucoup de nos participants ne sont pas conscients de l'existence de ce document, de son importance dans son contexte, .. et que beaucoup de ceux qui l'avaient connu, n'en avaient pas un souvenir précis ! Et c'est seulement avec le recul qu'on se rend compte que les progrès dans nos avions et leur sécurité intrinsèque, doivent beaucoup aux retombées de cet accident de Kegworth ! Et la compréhension au bénéfice des pilotes, aussi ! (Message édité par sevrien le 16/09/2008 03h27) |
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etops
Inscrit le 28/04/2008 |
# 13 septembre 2008 08:20 | |
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Merci d' avoir développé le sujet là où je m' étais limité à la présentation du problème : - question d 'ergonomie des instruments - question de formation / entrainement . Effectivement les nouvelles technologies censées diminuer les charges de travail et donc par certains aspects ,censées réduire les risques " facteurs humains " , ont en fait crée de nouveaux problèmes " facteurs humains " pour la sécurité des vols . Effectivement la conception peut creuser un trou où les pilotes peuvent tomber , mais les autres trous des plaques de ce cher Mr Reason sont aussi là . Aux pilotes de ne pas rater trop de plaques ! Le problème est qu'ils sont en bout de chaîne . d'où l' approche systémique faite actuellement des accidents . Me viennent en tête l' accident A 320 de Bahrein et le récent A320 Arménien ( Sotchi ? ) , mais le 320 n' a pas l' exclusivité , bien que certaines de ses technologies y contribuent qq peu . La lecture des 2 rapports est très intéressante . (Message édité par ETOPS le 13/09/2008 08h21) |
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sevrien
Inscrit le 08/08/2006 |
# 13 septembre 2008 08:41 | |
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Pour compléter cette série de documents sur l'affaire de Kegworth, ci-dessus, voici un dernier document qui vaut la peine d'être lu et compris ! Désolé ! Je ne traduis pas ! Lien : http://ezinearticles.com/?Kegworth-Air- ... id=1024617 Kegworth 1989: an accident waiting to happen? On January 8, 1989, routine domestic flight 092 was enroute from London Heathrow airport to Belfast in Northern Ireland. It was the second flight undertaken by the British Midland Boeing 737-400 that day and the aircraft was close to its landing destination when a combination of mechanical and human error led to disaster. Et, dans ce cas précis, ... il ne faut jamais oubler la partie "erreur / défaut mécanique" --------------------- Preparing to land at the East Midlands airport, the aircraft (tail marked G-OBME) plummeted onto an embankment of the M1 motorway near Kegworth, Leicestershire, killing 47 people and seriously injuring a further 74, including seven members of the flight crew. In summarising the cause of the accident, The Aircraft Accident Report stated "The cause of the accident was that the operating crew shut down the No.2 engine after a fan blade had fractured in the No.1 engine. This engine subsequently suffered a major thrust loss due to secondary fan damage after power had been increasing during the final approach to land" (AAIB 1980, 35). Commentaire à noter : This much is certainly true, however it was a combination of errors, mechanical, procedural and cognitive, which ultimately caused the aircraft to fail during its final landing phase. -------------------- In order to extrapolate the events of that day it is necessary to examine a chain of events rather than to study each constituent error or malfunction in turn. Et il fut dit à l'époque, et est reconnu aujourd'hui que : -- la prose de l'époque de l'AAIB aurait pu être mieux organisée, structurée, et 'nuancée' dans un "mouvement de texte" mieux rédigé, pour réfléchir ce qui suit. As is often the case with aircraft crash investigation, a sequence of human and operational errors tends to produce a domino effect in which it is the inertia of one event beyond another that results in a catastrophic conclusion (Job,1996; 173). The chronology of these events is therefore particularly important in helping to analyse the failure chain that led up to the crash. Notez bien la prose qui précède : "La chronologie est particulièrEment importante, dans l'aide à l'analyse de la "chaine d'échecs" / 'des défaillances', qui ont précédé et conduit jusqu'àu 'crash' ! Les faits, ... oui ! Mais bien inséreés et appréciés dans leur séquencement, timing et contexte exacts, comme un ensemble, ... une chaine qui fasse entité ! ----------------- G-OBME was engaged on a double shuttle run between London Heathrow airport and Belfast Aldergrove Airport. The first leg of the journey was uneventful. During the second leg of the shuttle the aircraft climbed initially to six thousand feet where it levelled-off for about two minutes before receiving clearance to climb to a flight level of twelve thousand feet. At 7.58 p.m., clearance was given to climb to thirty five thousand feet. At 8.05 p.m. as the aircraft was climbing through flight level 283 the crew experienced severe vibration and a smell of fire. No fire warnings, visual or audible were alerted by instruments on the flight deck. A noter ! -------------------------------- A later replay of the Flight Data Recorder showed that severe vibrations had occurred in the No.1 (left) engine, together with indications of an erratic fan speed, a rise in exhaust temperature and a low, variable fuel flow (AAIB, 1980; 145). D'une importance capitale ! -------------------------- Captain Hunt took control of the aeroplane..... A noter ! "Prit / reprit les commandes" ! ---------------------- ..............and disengaged the autopilot. He later claimed that the engine instrumentation did not give him any clear indication of the source of the malfunction. He also later stated that he thought that the smoke was coming forward from the passenger cabin which, from his understanding of the 737's air conditioning system, led him to believe that the smoke was in fact coming from the No 2 (right) engine. Consequently the command was issued to throttle back the No.2 engine. As a result of this procedure the aircraft rolled slowly to the left through sixteen degrees but the commander made no corrective movements of either rudder or aileron. D'une importance capitale ! --------------------- The commander later claimed that reducing the throttle of No.2 engine reduced the smell and signs of smoke and but he later remembered that the significant vibration continued after the No.2 throttle was closed. After throttling back the No.2 engine, London Air Traffic Control were immediately advised of an emergency situation with appeared to be an engine fire. Forty-three seconds after the onset of the vibration the commander ordered First Officer McClelland to "shut it down". The shut down was delayed at the First Officer responded to radio messages from London Air Traffic Control asking which alternative airport they wished to land at. Shortly after shutting down No.2 engine BMA Operations requested the aircraft divert to the East Midland Airport (AAIB,1980; 40). As soon as the No.2 engine had been shut down, all evidence of smoke cleared from the flight deck which further convinced the Commander that he had made the correct decision, not least in that No.1 engine showed no signs of malfunctioning and continued to operate albeit at reduced power and with increased fuel flow. Le problème des symptômes ! ------------------------- Passengers were aware of smoke and of smells similar to "oil" or "rubber" in the cabin. Some passengers saw evidence of fire from the left engine, and several cabin attendants saw fire from the No.1 engine as well as light coloured smoke in the cabin. Despite indication that the fire was emanating from the other engine neither passengers nor cabin crew alerted the flight crew to this fact. This may have been due to general confusion at the time, allied with a belief that the pilot ultimately knew what he was doing. "A false sense of security" ! Nous connaissons tous cela , "Euh, je pensais que ... tout allait bien " ! C''est toute la vie humaine ! --------------------------------- At 8.20 p.m. at a height of three thousand feet power was increased on the No.1 engine. The aircraft was then cleared to descend to two thousand feet and, after joining the centre line at two thousand feet above ground level (agl) the Commander called for the landing gear to be lowered and fifteen degrees to be applied to the flaps. At nine hundred feet there was a sudden decrease in power from the No.1 engine. As the aircraft dipped below the glidepath and the ground proximity warning system (GPWS) sounded the Commander broadcast "prepare for crash landing" on the cabin address system. The aircraft hit the ground at 8.24 p.m. at a speed of 115 knots. "Hélas ! Apparemment "job done " ! Mais, ... désastre" ! ----------------------- One survivor, Gareth Jones, described the moment when the plane hit the ground as follows: "There was a shudder, crash, like a massive motor car accident, crunch, blackness, and I was by the emergency hatch." (BBC, 1989). The AAIB report (AAIB, 1980; 35) concentrated upon the failure of the flight crew to respond accurately to a malfunction in the Number 1 engine, and highlighted the following operational errors: 1. The combination of engine vibration, noise and the smell of fire were outside their training and expertise. 2. They reacted to the initial engine problem prematurely and in a way that was contrary to their training. 3. They did not assimilate the indications on the engine instrument display before they throttled back the No.2 engine. 4. As the number 2 engine was throttled back, the noise and shuddering associated with the surging of the No.1 engine ceased, persuading them that they had correctly identified the defective engine. 5. They were not informed of the flames which had emanated from the No.1 engine and which had been observed by many on board, including 3 cabin attendants in the aft cabin. Many accident reports cite human failure as a primary cause (Johnson, 1998). ------------------ L'auteur est courageux, ici ! Et seulment les 'aveugles' et 'intellectuellment obtus' ne reconnaissaent pas la validité de sa prose ! However, before looking at the obvious failure in Captain Hunt's inability to determine which of the 737's engines had indeed malfunctioned, attention should be drawn to the faulty engine itself. Oui ! ------------------ The actual cause of the malfunction was a broken turbine, itself the result of metal fatigue caused by excessive vibration. Voilà la "root cause" ! Ni plus ni moins ! The upgraded CFM56 engine used on the 737-400 model were subject to excessive amounts of vibration when operating at higher power settings over twenty five thousand feet. Défaut inhérent au moteur ! Vraie cause initiale ! "Root cause" ! --------------------------- Because this was an upgrade to an existing engine, the engine had only ever been tested in a laboratory, not under actual flight conditions. Méthode de l'époque ! Sous l'influence de qui et de quoi ? -------------------- When this fact was subsequently discovered around a hundred 737-400's were grounded and the engines subsequently modified. Dans l'intérêt de tous ! Et il est clair qu'aucune personne "right thinking" (pour les obsédés politiques,..... rien à voir avec la droite ou la gauche, .... ; terme reconnu dans le droit international et 'anglo-saxon', ....) n'allait abandonner les pilotes dans ces circonstances ! ------------------------------------------ Since the Kegworth crash all significantly redesigned turbofan engines must be tested under actual flight conditions. Oui ! ------------------------ Arguably then, the inadequately tested CFM56 engine on flight 092 may have been "an accident waiting to happen" (Owen, D. 2001; 132). ---------------------- The AAIB report concluded that the combination of engine vibration, noise and the smell of fire were outside the flight deck crew's area of expertise. (AAIB, 1980). This may or may not be a fair assessment since few pilot's and First Officer's fortunately ever experience the actual effects of smoke and fire while in command. Remarque judicieuse. ------------------ Whilst simulators can help train for emergency procedures it is questionable how valuable such procedures may be, particularly if the crew have not been thoroughly trained on the unique procedural and technical requirements involved in flying a particular aircraft variant. Significantly, the flight crew of 092 had little belief in the accuracy of key instrumentation including vibration meters. -------------------- Dr Denis Besnard of Newcastle university analysed the Kegworth air crash, concluding "The pilots of the B737 were caught in what is known as a confirmation bias where, instead of looking for contrary evidence, humans tend to overestimate consistent data. People overlook and sometimes unconsciously disregard data they cannot explain" (Besnard D, 2004; 117). Nous avons déjà cité ceci, ci-dessus, me semble-t-il. -------------------- "Confirmation bias", i.e. the overloading of consciousness by a quantity of bewildering or conflicting data was also established as a primary cause of the crash when investigated by a research team from the University of York and the University of Newcastle upon Tyne. The argument that people tend to over simplify complex situations particularly during crisis has been is both well documented and significant in the causation of the Kegworth air crash (Besnard. D., Greathead, G. & Baxter, G, 2004; 117-119). Il convient de reconnaître ceci ! On le voit quand les gens refusent le détail, n'est-ce pas, et préfèrent sauter à la conclusion ! "Le problème est tout simple" ! Oui : à poser ! Pas à résoudre ! ---------------------- Specifically, Captain Hunt had not received training on the new model 737-400 since no simulators for this variant existed in the UK at that time. A l'époque, il en existait combien en Europe ? Les cies. achetaient "des lapins dans un sac" ! -------------------- This is both startling and critical when considering the following points. The captain believed the right engine was malfunctioning due to the smell of smoke, possibly because in previous Boeing 737 models the air for the air conditioning system was taken from the right engine. However, starting with the Boeing 737-400 variant, Boeing redesigned the system to use bleed air from both engines. Captain Hunt would have been unaware of this fact, which formed a critical part of his decision to shut down the wrong engine. This would prove disastrous. La faute des pilotes ? Quid de l'information, de la comunication, ... de la formation? ----------------- Apart from the coincidence of the smoke vanishing when the auto-throttle was disengaged, the pilots may have also been in the habit of disregarding the readings of vibration warning meters, since early ones were perceived to be unreliable. The crew of G-OBME do not seem to have been aware that newer ones were, however, more reliable. Should more attention have been paid, therefore, to vibration issues rather than to smoke and the smell of fire, events may well have transpired very differently on the evening of January 8th (Owen, 2001; 131-2). Question plus que pertinente ! ------------------------ Subsequent research has critically concluded that "organisational failures create the necessary preconditions for human error" and "organisational failures also exacerbate the consequences of those errors" (Stanton, 1994; 63). The Kegworth air crash was therefore the result of a sequence of failures originating from a mechanical defect. La conclusion ci-dessus est la vraie conclusion, qui, heureusement, a changé "la pensée unique" de l'époque ! ---------------------------- Additionally, cognitive error on the part of the flight crew ; ... -- enhanced by inadequate flight training compounded the error chain. A noter ! ----------------- Finally the flight crew did not verify their interpretation of events by consulting with cabin staff or passengers even though information to suggest the fault lay with the other engine on the aircraft was available at the time. A ne pas négliger ! ----------------------------- Bibliography BBC (1989) On This Day: Dozens die as plane crashes on motorway. [online] available from http://news.bbc.co.uk/onthisday/hi/date ... /january/8 [accessed 2 March 2007] Besnard, D. (2005) International Aviation and Fire Protection Association. [online] available from http://www.iafpa.org.uk/news-template.p ... mp;id=1312 [accessed 1 March 2007] Besnard, D., Greathead, G., and Baxter, G., (2004) International Journal of Human-Computer Studies. When mental models go wrong. Co-occurrences in dynamic, critical systems, Vol. 60, pp. 117-128. Job, M. (1996) Air Disaster Volume 2. pp. 173-185. Aerospace Publications Pty Ltd Johnson, D. 1988; University of Glasgow Department of Computing Science (1980) Visualizing the Relationship between Human Error and Organizational [online] University of Glasgow, 1980. http://www.dcs.gla.ac.uk/~johnson/paper ... error.html [accessed 2 March 2007] Owen, D. (2001) Air Accident Investigation, 1st ed., Ch. 9, pp. 132-152. Sparkford, Patrick Stephens Limited Stanton, N.A., (1994) The Human Factors of Alarm Design, Ch. 5, pp. 63-92. London, Taylor and Francis Ltd UNITED KINGDOM. Air Accidents Investigation Branch (1990) Boeing 737-400, G-OBME, near Kegworth, Leicestershire 8th January 1989, number 4/90. London, HMSO. Duncan Rosslair is a freelance author specialising in aviation history. For more information about writing articles online for pleasure and profit view (Message édité par sevrien le 13/09/2008 09h02) |
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LIGHTWEIGHT1
Inscrit le 21/03/2008 |
# 13 septembre 2008 08:48 | |
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Suite à l' accident du mont Ste Odile, l 'ergonomie du PA a été modifiée. Je ne sais comment les boutons d' affichage ont été modifiés (séparation pente de descente et Vz), mais plusieurs pilotes d' essais n' avaient soupçonné le risque de confusion d' affichage jusque là, malgré leur expérience. Mais expérience différente de celle d' un pilote de ligne. |
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Airfan
Inscrit le 25/08/2006 |
# 13 septembre 2008 15:00 | |
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Bonjour à tous, Je ne voudrais pas participer à la polémique 777, mais un nouvel incident sur un T7-300 d'Air Canada. La nature n'a pas été révélé, mais il semble que ce soit mécanique. Je pense que l'on peut faire confiance à ce site. L'info sur ce lien : http://www.crash-aerien.com Si vous avez d'autre infos, je suis preneur. (Message édité par Airfan le 13/09/2008 15h01) (Message édité par Airfan le 13/09/2008 15h08) |
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Beochien
Inscrit le 13/02/2007 |
# 13 septembre 2008 15:48 | |
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Merci Airfan Soigner le lien d'abord !! Ca ne coûte pas plus cher ! http://www.crash-aerien.com/www/news/ar ... mp;check=0 Vu dans les commentaires ... détournement de 3 Heures .... ils ont quelles Etops chez AC ?? Bon, PB mécanique, maintenant savoir si c'est un moteur .... ??? _________________ JPRS |
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