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Emirates B777 gear collapse @ DXB?

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Emirates B777 gear collapse @ DXB?

Old 8th Aug 2016, 09:27
  #621 (permalink)  
 
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No, the large nose gear doors you see are only open while the gear is in transit. Once locked down or up those large doors are closed. Only the smaller doors beside the wheels are down ( when the gear are down ).......

So what does this mean? Perhaps the wheels were in transit when ground contact happened........or possibly they were forced open by the impact? We don't know.

Last edited by ACMS; 8th Aug 2016 at 09:46.
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Old 8th Aug 2016, 09:37
  #622 (permalink)  
 
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Oh and take a look at a 777 landing Flap from behind, the inboard and outboard Flaps appear to be different angles. The inboard Flaps are double slotted ( correct term? ) while the outboard are not. Thus appearing to be different.
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Old 8th Aug 2016, 09:44
  #623 (permalink)  
 
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Great pic, and the nose wheel doors are open!
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Old 8th Aug 2016, 09:47
  #624 (permalink)  
 
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No actually only the small doors are open mate, which is normal.

The large nose gear doors are located forward, basically under and slightly forward of the 2 right side pitot tubes and Ice detector when they are open. These doors you see on the Air France 777 landing are the smaller doors only. The big doors are closed.

Look at the normal photo I've included of a EK 777 retraction in this reply, the main nose gear doors are under and slightly forward of the Pitot tubes, now look at the crash photo again.

On the EK 777 crash photo above the large doors are open........indicating the gear was most likely in transit.....

Ok

Last edited by ACMS; 8th Aug 2016 at 10:00.
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Old 8th Aug 2016, 09:52
  #625 (permalink)  
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Picture of large doors open.

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Old 8th Aug 2016, 12:37
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Originally Posted by ACMS


No actually only the small doors are open mate, which is normal.

The large nose gear doors are located forward, basically under and slightly forward of the 2 right side pitot tubes and Ice detector when they are open. These doors you see on the Air France 777 landing are the smaller doors only. The big doors are closed.

Look at the normal photo I've included of a EK 777 retraction in this reply, the main nose gear doors are under and slightly forward of the Pitot tubes, now look at the crash photo again.

On the EK 777 crash photo above the large doors are open........indicating the gear was most likely in transit.....

Ok
What makes me think the gear was RETRACTED at the moment of the impact.
On the contrary:
a.- if extended, could resist and do its job... or
b.- if extended and failed to cushion the impact, the belly would show a good quantity of damage once the gear broke and it doesn't to appear after the two pics posted by myself (sorry for the self-cites)

Since I leave this item for specialists, my question is: could the BIG GEAR DOORS be left opened by the impact? Is that a regular behavior considering the vital placement of that doors?
And the 777 seems to be a strong beast, at last...

Last edited by guadaMB; 8th Aug 2016 at 12:38. Reason: typo
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Old 8th Aug 2016, 13:37
  #627 (permalink)  
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Question

There is usually a temperature inversion in this part of the world during hot weather. It was not uncommon in the past to see aircraft whose performance was not what we have now on modern twins, struggle to get through it on takeoff.


I wonder if this combined with a WS event conspired to derail these guys.
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Old 8th Aug 2016, 13:41
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Hi Tech nice try to backtrack in post602 but ......

In post 574 you said.

If this is true "THE ATC MUST TAKE THE MAJOR BLAME" for allowing the aircraft to land when 2 had aborted. Are they not "NEGLIGENT" in letting an aircraft land on a runway end that had a weather issue." Absolute Bull****. I am surprised that "donpizmeov" and others from the pointy end haven't taken you to task. As I said before totally PIC decision to land.

In the UAE your post 574 could be considered libelous.

Last edited by Rule3; 8th Aug 2016 at 14:08. Reason: omission
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Old 8th Aug 2016, 14:22
  #629 (permalink)  
 
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OK Rule3
May be my choice of words was not proper. But wait for final report. I am sure there will be a mention of ATC. Of course one can say the PIC has the final word and he can ignore any warning or ignore the Clear to land call and GA. But I have heard several calls to PIC from tower 'Caution runway wet', 'Braking reported poor by pilot who landed ahead of you' etc. I would expect unusual winds worthy of some action or at least a caution.
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Old 8th Aug 2016, 14:43
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Hi Tech your words were libelous. I find it offensive in the extreme that you can BLAME the CONTROLLER and infer NEGLIGENCE.
Perhaps you should have waited til the Final report before you posted.

Your comments in post 637 clearly show you have a little knowledge. As we know a little knowledge is dangerous.

You should remove your posts. The controller gave the PIC the relevant info. The PIC made the decision. End of story.
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Old 8th Aug 2016, 17:50
  #631 (permalink)  
 
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Rule3

ATC(even operated by private entity) is a government function, libel laws won't apply.

If your goal is to send this thread to slammer, you are on the right track.
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Old 8th Aug 2016, 20:08
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What Byron Bailey is missing is that the PF should not only be focused on the pitch on his PFD, but also announce the FMA changes to ensure that the correct modes are engaged.
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Old 8th Aug 2016, 20:21
  #633 (permalink)  
 
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its behind the quasi-paywall, posted on the basis of public interest fair use given the nature of this site and the subject & content of the article.

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.
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Old 8th Aug 2016, 20:42
  #634 (permalink)  
 
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So, captains, how well do you know your aircraft systems?

Originally Posted by CurtainTwitcher
its behind the quasi-paywall, posted on the basis of public interest fair use given the nature of this site and the subject & content of the article.
To Captain Bailey's observation, which matches some of the estimates made in this thread, I will ask some flying related questions.
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.
Operating under the idea that his feeling may be correct ...

Does the type training cover this systems interaction?
If not, why not?
Does a bounce / go around get practiced in the sim?
If not, why not?
Is it SOP to put your hand on / guard the power levers for take off and landing?
If not, why not?
Is power delivered by the engines (check the indicator rise toward power expected/desired) during a go around a mandatory scan / cross check call out item, and is it called out?
If not, why not?
I understand how effective automatics generally are: to be fair, let's give the engineers and designers over the past few decades a hearty pat on the back. Some amazing tech has been developed with superb reliability.

This question is about flying.

Since aviation began, the closer one gets to the earth the more chances for an accident. (Note where so many accidents take place: during take off and landing events). The fact of an aircraft having a plethora of automatic features won't change that element of aviation.


My last question has to do with how I was trained ...


If you think the aircraft should be doing X,
and it isn't doing X,
have you been embedded in your training to ask "what is it doing?"
or is it "the plane's not doing X, I need to make it do X!" and act upon that?
Lastly: Boyd's infamous OODA loop isn't just for dog fights. Observe-Orient-Decide-Act-Observe ad nauseum until you have parked at the gate and unloaded all of your precious cargo.
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Old 8th Aug 2016, 20:46
  #635 (permalink)  
 
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Originally Posted by Lonewolf_50
let's give the engineers and designers over the past few decades a hearty pat on the back. Some amazing tech has been developed with super reliability figures.
Agreed.
I do think that perhaps there is a problem with pilots knowing more about flying than the way the computer is handling the aeroplane systems. Perhaps pilots should learn more about the logic computers follow when making decision x in their plane.
(NB. I'm not a commercial pilot. This view stems from a conversation with a recently ex-A320 captain who had a similar viewpoint. However, I am a programmer.)

Last edited by crablab; 8th Aug 2016 at 20:47. Reason: Repetition but not deviation
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Old 8th Aug 2016, 20:56
  #636 (permalink)  
 
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Mr Bailey is wrong, despite all his experience.
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Old 8th Aug 2016, 21:04
  #637 (permalink)  

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Crablab,

They need to know both: first how to fly the thing when all the gizmos start acting up - learn to recognise a discrepancy between what they expect and what they actually get, disconnect the whole shebang and just fly the thing. And secondly, know your mode laws - that could well prevent the fist skill from needing to be employed.

If you are equipped with the first set of skills, you will be safe. Maybe not smart - but safe. If you add the 2nd set of skills, you are mode proficient.

If you have the 2nd skill-set but not the first, you are safe until the mode logic misbehaves. After that, you are in the same boat as the guy who doesn't understand how the thing works in the first place.

Point is - peeps with the first skill-set can replace a computer. Peeps with only the 2nd skill-set can be replaced by a computer.

As a separate discussion - the high fidelity of simulators means that very few (if any) sims exists where you can simulate a misbehaving flight guidance or thrust mode. Same with bounces - they are kinda hard to generate realistically in the sim. We are so focussed on replicating the real thing that we cannot teach people how to handle flight guidance mis-cueing - we simply don't have the tools.
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Old 8th Aug 2016, 21:05
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Originally Posted by Oakape
Mr Bailey is wrong, despite all his experience.
In what respect, and how do you know ?
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Old 8th Aug 2016, 21:06
  #639 (permalink)  
 
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Mr Bailey, despite "having been" with Emirates, it looks like he still is....

It could have happened to any pilot
Sounds like a PR campaign
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Old 8th Aug 2016, 21:09
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Originally Posted by Empty Cruise
Point is - peeps with the first skill-set can replace a computer. Peeps with only the 2nd skill-set can be replaced by a computer.
Totally agree - and sometimes the computer spews a load of cr@p at you and there has to be training to deal with these situations (but as I gather from the next bit - it's not currently possible). Human + machine interfaces are getting more and more important; the computer is only as good as the melon behind it who has the power to turn it off and ignore the useful/useless advice it's giving. Although saying that, there is always an advantage to having something that has a vested interesting in staying alive behind the controls...
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