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777 Emirates - Acidente hoje em Dubai


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#61 Pessoa 1985

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Posted 10 de August de 2016 - 11:35

Seguem três fotos retiradas do facebook, autor desconhecido...

 

13887058_640357129456951_692899704719233

 

13962513_640357146123616_830922962760422

 

13901466_640357122790285_276240439813910


Edited by Pessoa 1985, 10 de August de 2016 - 11:37 .


#62 raverbashing

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Posted 10 de August de 2016 - 11:41

É, acho que esse nem pra panela vai servir mais...



#63 gusdalcolmo

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Posted 10 de August de 2016 - 15:25

Atualizações do AVHerald - http://avherald.com/...=49c12302&opt=0

 

A passenger in the aft cabin reported, that the approach was normal, there had been no announcements or indications of anything abnormal. Then there was a heavy impact, oxygen masks came down, the aircraft skidded shaking violently and immediately filling with smoke and came to a stop. All doors were opened, it appeared however not all of them were used for evacuation. After sliding down the chute the passenger began to run, about 100 meters from the aircraft an explosion was heard (editorial note: watch video "The aircraft erupting into flames", the right wing caught fire and including right hand engine separated from the aircraft).

Another passenger reported that the captain made an announcement they would land at Dubai and the weather was fine, nothing appeared to be amiss. Suddenly the aircraft hit the ground tail/belly first, at the same time the right hand engine caught fire, and the aircraft skidded to a halt, smoke filled the cabin, only at this time the passengers realised the seriousness of the situation. The accident came entirely out of the blue.

A ground observer reported EK-521 made a normal approach with the landing gear extended, touched down hard and went around, the gear was retracted, however the aircraft appeared to lack power and sank back onto the runway. (Editorial note: The Aviation Herald noticed the lack of a significant detail in the narration of passengers mentioned above, there was no mention of sounds of engines spooling up).

On Aug 8th 2016 a passenger reported in the reader comments on AVH below, that the approach was normal, the landing gear was down. The aircraft touched down, however, the nose was not lowered onto the runway and the aircraft appeared to climb away again, the gear was retracted, however, the engines did not spool up. The aircraft made ground contact again, skidded along the runway with the right hand engine separating from the aircraft but still being dragged along with the aircraft until the aircraft came to a full stop.



#64 Roadster

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Posted 10 de August de 2016 - 19:30

Esse trem parece travado... Mas estão falando que ele bateu na pista sem trem...

#65 MarceloF

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Posted 10 de August de 2016 - 21:52

Roadster,

Andei pensando a mesma coisa. Mas acho que estendeu e travou ao içar mesmo...



Recebido por whatsapp:

Emirates B777 crash was accident waiting to happen
BYRON BAILEYThe Australian12:00AM August 9, 2016
 
The crash of an Emirates B777 during an attempted go-around in Dubai last Wednesday was always an accident waiting to happen.
 
It was not the fault of the pilots, the airline or Boeing, because this accident could have happened to any pilot in any airline flying any modern glass cockpit airliner — Airbus, Boeing or Bombardier — or a large corporate jet with autothrottle.
 
It is the result of the imperfect interaction of the pilots with supposedly failsafe automatics, which pilots are rigorously trained to trust, which in this case failed them.
 
First, let us be clear about the effect of hot weather on the day. All twin-engine jet aircraft are certified at maximum takeoff weight to climb away on one engine after engine failure on takeoff at the maximum flight envelope operating temperature — 50 degrees C in the case of a B777 — to reach a regulatory climb gradient minimum of 2.4 per cent.
 
The Emirates B777-300 was operating on two engines and at a lower landing weight, so climb performance should not have been a problem. I have operated for years out of Dubai in summer, where the temperature is often in the high 40s, in both widebody Airbus and Boeing B777 aircraft.
 
Secondly, a pilot colleague observed exactly what happened as he was there, waiting in his aircraft to cross runway 12L. The B777 bounced and began a go-around. The aircraft reached about 150 feet (45 metres) with its landing gear retracting, then began to sink to the runway.
 
This suggests that the pilots had initiated a go-around as they had been trained to do and had practised hundreds of times in simulators, but the engines failed to respond in time to the pilot-commanded thrust. Why?
 
Bounces are not uncommon. They happen to all pilots occasionally. What was different with the Emirates B777 bounce was that the pilot elected to go around. This should not have been a problem as pilots are trained to apply power, pitch up (raise the nose) and climb away. However pilots are not really trained for go-arounds after a bounce; we practise go-arounds from a low approach attitude.
 
Modern jets have autothrottles as part of the autoflight system. They have small TOGA (take off/go-around) switches on the throttle levers they click to command autothrottles to control the engines, to deliver the required thrust. Pilots do not physically push up the levers by themselves but trust the autothrottles to do that, although it is common to rest your hand on the top of the levers. So, on a go-around, all the pilot does is click the TOGA switches, pull back on the control column to raise the nose and — when the other pilot, after observing positive climb, announces it — calls “gear up” and away we go!
 
But in the Dubai case, because the wheels had touched the runway, the landing gear sensors told the autoflight system computers that the aircraft was landed. So when the pilot clicked TOGA, the computers — without him initially realising it — inhibited TOGA as part of their design protocols and refused to spool up the engines as the pilot commanded.
 
Imagine the situation. One pilot, exactly as he has been trained, clicks TOGA and concentrates momentarily on his pilot’s flying display (PFD) to raise the nose of the aircraft to the required go-around attitude — not realising his command for TOGA thrust has been ignored. The other pilot is concentrating on his PFD altimeter to confirm that the aircraft is climbing due to the aircraft momentum. Both suddenly realise the engines are still at idle, as they had been since the autothrottles retarded them at approximately 30 feet during the landing flare. There is a shock of realisation and frantic manual pushing of levers to override the autothrottle pressure.
 
But too late. The big engines take seconds to deliver the required thrust before and before that is achieved the aircraft sinks to the runway.
 
It could have happened to any pilot caught out by an unusual, time-critical event, for which rigorous simulator training had not prepared him.
 
Automation problems leading to pilot confusion are not uncommon; but the designers of the autoflight system protocols should have anticipated this one. Perhaps an audible warning like “manual override required” to alert the pilots immediately of the “automation disconnect”.
 
My feeling is the pilots were deceived initially by the autothrottle refusal to spool up the engines, due to the landing inhibits, and a very high standard of simulator training by which pilots are almost brainwashed to totally rely on the automatics as the correct thing.
 
Byron Bailey is a commercial pilot with more than 45 years’ experience and 26,000 flying hours, and a former RAAF fighter pilot. He was a senior captain with Emirates for 15 years







Se alguém que voa 777 puder dar uma luz... O TO/GA dele é mesmo inibido por esse motivo? Achei pra lá de estranho  :blink:

EDIT: Já apareceu a luz, A/T entrou em "RETARD"...

Edited by MarceloF, 10 de August de 2016 - 21:56 .


#66 pilotoKAL

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Posted 11 de August de 2016 - 06:01

Vamos por partes novamente, sistemas automáticos não são (por desenho ) fail safe, são sim error tolerant , ou seja, operou fora dos padrões acontece algo ruim. Não irei entrar na analise do acidente pois avaliar um evento serio com sem dados concretos é especulação. Em relação a bounced landing, existem dois tipos: low bounce( em que o avião toca na pista e sobe ate 5 ft ,isto no caso do B777), para recuperar este se mantém o pitch e adiciona potência se necessário ate o pouso no segundo toque, o outro seria o high bounce(maior que 5ft) e neste caso e go around mesmo e observando o tail clearence(espaço entre a cauda e chão) , isto posto vamos ao TOGA, no solo na decolagem este gatilho(os botões são em forma de gatilho invertido na frente das manetes) tem como função básica engatar o modo de decolagem para o sistema todo, não apenas para o autothr...no caso de uma arremetida no solo ( se chama rejected landing) , o botão fica inibido , vamos as partes do FCOM :

Autothrottle disconnect occurs automatically:

  • if a fault in the active autothrottle mode is detected

  • when either reverse thrust lever is raised to reverse idle

  • if the thrust levers are overridden during a manual landing, after the

    autothrottle has begun to retard the thrust levers to idle

  • when both engines are shut down 

The TO/GA switches are inhibited when on the ground and enabled again when in the air for a go–around or touch and go.

With the first push of either TO/GA switch:

  • roll and pitch activate in TO/GA

  • autothrottle activates in thrust (THR) to establish a minimum climb rate of 2,000 fpm

  • the AFDS increases pitch to hold the selected speed as thrust increases

  • if current airspeed remains above the target speed for 5 seconds, the target airspeed is reset to current airspeed (to a maximum of the IAS/MACH window speed plus 25 knots)

O avião entende dois modos básicos: no solo ou em voo , estes modos são ativados por switches no trem de pouso(air/ground switches) , no solo com os amortecedores comprimidos o trem não consegue ser recolhido, apenas quando o solenoide entra no modo voo a alavanca do trem é destravada, para uma arremetida no solo , o ajuste de potência é feito manualmente, isto é treinado em simulador, inclusive o bounced landing e etc... 

 

​O 777 opera sempre ATS ON, não existe caso previsto em que se desligue o ATS.



#67 Darui

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Posted 13 de August de 2016 - 20:12

Mesmo com 100% se não deu tempo de pegar velocidade antes de fazer o bico subir iria dar stall de qualquer jeito.



#68 Caravelle

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Posted 01 de September de 2016 - 14:38

Obviamente, ninguém quer um acidente ou incidente aéreo e devemos todos ter a segurança de voo como objetivo primordial.

 

Mas não deixa de ser irônico que esse acidente está inclinando-se para ter como um dos fatores contribuintes o automatismo, algo tão criticado pelos "boeingueiros" como "excessivo" nas aeronaves da Airbus, normalmente sem conhecer a aeronave e baseados em factoides.

 

Me parece muito mais intuitivo o acionamento do TO/GA no autothrust dos Airbus - manetes todas à frente, do que os botões do autothrottle da Boeing. Embora, se lembro bem, no Boeing é possível empurrar a manete toda à frente e sobrepujar o autothrottle.



#69 3Setão

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Posted 01 de September de 2016 - 18:52

é por isso que prefiro o ATR!!! :bumbo: :bananarider: :drinks: :cool:



#70 raverbashing

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Posted 06 de September de 2016 - 07:10

Relatório preliminar saiu http://www.airlive.n...-dubai-airport/



#71 Nimbus

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Posted 06 de September de 2016 - 21:00

Relatório preliminar saiu http://www.airlive.n...-dubai-airport/

At 0837:35, three seconds before impact with the runway, both thrust levers were moved from the idle position to full forward.

 

arremeteu sem arremeter. =(



#72 Stabilizer Motion

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Posted 09 de September de 2016 - 14:32

Voc

 

Vamos por partes novamente, sistemas automáticos não são (por desenho ) fail safe, são sim error tolerant , ou seja, operou fora dos padrões acontece algo ruim. Não irei entrar na analise do acidente pois avaliar um evento serio com sem dados concretos é especulação. Em relação a bounced landing, existem dois tipos: low bounce( em que o avião toca na pista e sobe ate 5 ft ,isto no caso do B777), para recuperar este se mantém o pitch e adiciona potência se necessário ate o pouso no segundo toque, o outro seria o high bounce(maior que 5ft) e neste caso e go around mesmo e observando o tail clearence(espaço entre a cauda e chão) , isto posto vamos ao TOGA, no solo na decolagem este gatilho(os botões são em forma de gatilho invertido na frente das manetes) tem como função básica engatar o modo de decolagem para o sistema todo, não apenas para o autothr...no caso de uma arremetida no solo ( se chama rejected landing) , o botão fica inibido , vamos as partes do FCOM :

Autothrottle disconnect occurs automatically:

  • if a fault in the active autothrottle mode is detected

  • when either reverse thrust lever is raised to reverse idle

  • if the thrust levers are overridden during a manual landing, after the

    autothrottle has begun to retard the thrust levers to idle

  • when both engines are shut down 

The TO/GA switches are inhibited when on the ground and enabled again when in the air for a go–around or touch and go.

With the first push of either TO/GA switch:

  • roll and pitch activate in TO/GA

  • autothrottle activates in thrust (THR) to establish a minimum climb rate of 2,000 fpm

  • the AFDS increases pitch to hold the selected speed as thrust increases

  • if current airspeed remains above the target speed for 5 seconds, the target airspeed is reset to current airspeed (to a maximum of the IAS/MACH window speed plus 25 knots)

O avião entende dois modos básicos: no solo ou em voo , estes modos são ativados por switches no trem de pouso(air/ground switches) , no solo com os amortecedores comprimidos o trem não consegue ser recolhido, apenas quando o solenoide entra no modo voo a alavanca do trem é destravada, para uma arremetida no solo , o ajuste de potência é feito manualmente, isto é treinado em simulador, inclusive o bounced landing e etc... 

 

​O 777 opera sempre ATS ON, não existe caso previsto em que se desligue o ATS.

 

 

Vocês tem treinamento de bounce landing? Digo, no simulador... Não apenas na leitura...



#73 pilotoKAL

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Posted 09 de September de 2016 - 20:54

Voc

 

 

 

Vocês tem treinamento de bounce landing? Digo, no simulador... Não apenas na leitura...

 

Opa, temos sim !! Este tipo de treinamento se chama SPOT Training...



#74 Velinho

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Posted 12 de September de 2016 - 19:50

Bem o que da pra deduzir deste pre-relatório é que ocorreram duas falhas básicas na execução do go-around (FCTM):

 

1- Não foi observado o spoll up dos motores.

2- Não foi observado o positive climb no altímetro para solicitar o gear-up.

 

Manobra exaustivamente mal treinada nos recurrents da EK  

 

"Rápido e mal feito"

 

Serve o aprendizado.