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Emirates 777-31H, (EK521) Accident - Final Report Out

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Emirates 777-31H, (EK521) Accident - Final Report Out

Old 16th Feb 2020, 04:26
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The discussion here is of academic interest only and probably belongs in another thread on automation. The Operator in question here does not allow the use of manual thrust, or raw data, at all. Mistakes can be career ending. I fly almost 1000 hours per year and the last thing I feel like after a 15 hour flight arriving at my circadian low is to prove my mettle by challenging myself to a manually flown approach.

Address those issues first before calling the pilots lazy.
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Old 16th Feb 2020, 08:12
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In this accident training might have helped, so too a better design of automation. Our choice is with hindsight, where the challenge is to foresee such situations and avoid them, require improved technology and the best of human abilities to manage situations which we have difficulty in imagining.
I don’t really agree that our choice is with hindsight.
The reliance on the auto-thrust in high workload situations on types where it is engaged for every departure, cruise and landing has been discussed for years. From memory I think it might have even come up in the 777 accident report that cart-wheeled in the states.
In a high workload situation the basics of flying should be available through muscle-memory.
When they forgot to follow through, you fail the A/T and let nature take its course
Sounds like good training to me.
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Old 16th Feb 2020, 15:15
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The report seems to overlook the fact that TOGA buttons are a stupid design in the first place, especially with FADEC. Regardless of your opinion of Airbus non-moving thrust levers, this is an aspect they got absolutely spot on.

Go-around = firewall the thrust levers. None of this messing around with buttons (accidentally disconnecting the AT instead of TOGA and vice-versa is still a common problem), and you can get rid of the utterly pointless “HOLD” mode that’s a hangover from shit design* in the 70s.

* HOLD actively disconnects power from the autothrottle servos in two separate ways. God only knows what happened that required this to be introduced in the first place.

Last edited by Fursty Ferret; 16th Feb 2020 at 19:05.
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Old 16th Feb 2020, 16:06
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“The Operator in question here does not allow the use of manual thrust, or raw data, at all.”

in this case neither pilot realized that the wheels had touched down and Auto Go Round had been inhibited, there must be cases where GA has to be done after touch down, therefore manual thrust would have to be used.

Is inhibiting auto throttle as soon as the gear touches down a good idea and why is it not cancelled when the GA button is pressed

That aside, because following through every automatic action monitoring becomes casual, in a Go Around situation which is uncommon I would be on those throttles immediately as would any GA pilot, rules or no rules.
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Old 16th Feb 2020, 17:01
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May not be desirable but there are two different go around procedures in Boeing. Goaround without touchdown is the much practiced even experienced event. The need for the other after touchdown procedure is so rare that one may not remember when needed. Manufacturer may or may not change it in near future but if it is included in approach briefing it will prevent recurrence of this accident. Even mere knowledge that TOGA switches won't work is enough to execute it.

Last edited by vilas; 16th Feb 2020 at 17:14.
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Old 16th Feb 2020, 17:12
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Originally Posted by Fursty Ferret View Post
The report seems to overlook the fact that TOGA buttons are a stupid design in the first place, especially with FADEC. Regardless of your opinion of Airbus non-moving thrust levers, this is an aspect they got absolutely spot on.

Go-around = firewall the thrust levers. None of this messing around with buttons (accidentally disconnecting the AT instead of TOGA and vice-versa is still a common problem), and you can get rid of the utterly pointless “HOLD” mode that’s a hangover from shit design* in the 70s.
Fursty, as a bus driver I am in complete agreement with your sentiment. However, the report did not overlook the poor design at all. The investigation can't really tell Boeing their system is junk. That would be apportioning blame which is not the idea of accident investigation. They did highlight several shortcomings in the combination of system & procedure. Boeing will have some thinking to do after reading the report but, unfortunately, will probably follow their standard line of pilots should know what they are doing in order to avoid any product liability.

“The Operator in question here does not allow the use of manual thrust, or raw data, at all.”

in this case neither pilot realized that the wheels had touched down and Auto Go Round had been inhibited, there must be cases where GA has to be done after touch down, therefore manual thrust would have to be used.

Is inhibiting auto throttle as soon as the gear touches down a good idea and why is it not cancelled when the GA button is pressed

That aside, because following through every automatic action monitoring becomes casual, in a Go Around situation which is uncommon I would be on those throttles immediately as would any GA pilot, rules or no rules.
DS10, the reason the TOGA switches are disabled on the ground is to prevent problems when they are triggered accidently during ground operations.But yeah, that is a bandaid on a very poor design.
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Old 23rd Feb 2020, 12:11
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Go-around = firewall the thrust levers. None of this messing around with buttons
Embedded at page 87 of the GCAA accident report, and edited for brevity, the investigator concludes:

"that a manual advancement of the thrust lever followed pushing to TO/GA switch as the aircraft gains altitude will ensure that the crew will remain in control and maintain full awareness of change in engine thrust.... the investigator recommends that the FAA performs a safety study in consultation with aircraft manufactures for the purpose of enhancing the autothrottle system and TO/GA switch inhibit logic so that pilot errors due to overreliance on automation will be avoided".

There is more, but turn to page 87 if desired. Trigger Alert - the complete report takes a lot of reading.

Manually advancing the thrust levers towards GA and then pushing TO/GA as a secondary action, is good airmanship during a low altitude go-around. At the very least, a pilot can feel the thrust increasing rather than assuming power will increase on pushing a button.

The momentary hesitation and initial confusion that is bound to occur if pushing TO/GA fails to give the expected increase in power can lead to a critical situation as the crew of the ill-fated Emirates 777 discovered to their cost.
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Old 24th Feb 2020, 09:17
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Go-around = firewall the thrust levers. None of this messing around with buttons
Except that you need them for f/d guidance. And automatic go around as well (which btw in some situations like IMC is far more desirable then a manual one. There have been many accidents due to somatogravic illusions and A/P doesn’t suffer from that).

But as far as thrust goes, I agree that it is wrong that Boeing has long ago changed SOPS during g/a to hit the button first and then ensure thrust is set, without hanging on to the well established habit of shoving the thrust levers forward.
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Old 24th Feb 2020, 09:54
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Originally Posted by Dave Gittins View Post
The gulf between my flying as a GA pilot .. wholly manually. And airline flying which seems more and more focussed on "automation must be used at all times" is widening. And it doesn't appear to be helping safety one tiny bit. Would removing the mandate to use auto throttle at all times have avoided this one ?
I am not a pilot so feel free to ignore my comment but all the evidence suggest that safety has improved enormously. I suppose there is room to argue that the reason for this is something other than increased automation/support for the pilots from aircraft systems but this seems unlikely and it would need some very strong evidence that this was the case.

See for example:
https://aviation-safety.net/graphics...-1946-2017.jpg
https://aviation-safety.net/graphics...-1977-2017.jpg

I do work in the design fo safety related systems in all sorts of areas and a common phenomenen is a resistance to systems designed to assist and to prevent forseeable errors which have severe consequences when it is seen as redcing teh skill, prestige, authourity of operators. The reality is that the safest systems are ones in which automation/intelligent systems, people, training and procedures work together covering the weaknesses of one approach with the strengths of another. Automation is not a silver bullet, it won't solve every problem, it will introduce some new problems, but used judicously it will help. A view that automation per se is bad will definitely hinder progress towards being even safer.
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Old 24th Feb 2020, 10:07
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Originally Posted by golfyankeesierra View Post
Except that you need them for f/d guidance. And automatic go around as well (which btw in some situations like IMC is far more desirable then a manual one. There have been many accidents due to somatogravic illusions and A/P doesn’t suffer from that).

But as far as thrust goes, I agree that it is wrong that Boeing has long ago changed SOPS during g/a to hit the button first and then ensure thrust is set, without hanging on to the well established habit of shoving the thrust levers forward.
u no

The capt was flying the HUD. This requires the toga to be actuated, just as the FD does. What both then show is the GA pitch. If you are in a wind shear close to ground recovery, however the drill is to get every last bit of energy out of the aircraft to get clear of the deck.
That requires pitch above - and IAS below GA values - until clear of ground. And by the way in the latter case, our company required AP / ATS off, as first actions (followed by much pitch up and thrust increase to the stops) so the toga only affected the flight guidance items - which anyway don’t display what you are temporarily trying to fly.
In a fatigued situation the choice might not be apparent.
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Old 24th Feb 2020, 10:40
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Except that you need them for f/d guidance. And automatic go around as well (which btw in some situations like IMC is far more desirable then a manual one. There have been many accidents due to somatogravic illusions and A/P doesn’t suffer from that).
Certainly on the Airbus setting the thrust levers to the TOGA detent (ie fully forward) triggers the go-around mode anyway (provided the flaps are at least position 1). Trivial to sense this thrust lever position on any aircraft type.
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Old 24th Feb 2020, 12:07
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Am I the only one to think that there was a complete failure of workload management and prioritisation that the F/O was talking on the radio replying to tower before the Captain had even called for gear up? Several airlines used to have an SOP of no R/T below 1000 feet agl on a go around. I can't help thinking that if the PM had not been distracted he might actually have monitored the EPR as required and noticed in time - which is what I always thought the M in PM was meant to be about...
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Old 24th Feb 2020, 13:54
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Originally Posted by BizJetJock View Post
Am I the only one to think that there was a complete failure of workload management and prioritisation that the F/O was talking on the radio replying to tower before the Captain had even called for gear up? ....... I can't help thinking that if the PM had not been distracted he might actually have monitored the EPR as required and noticed in time .....
My thoughts too - and, while the Report identifies the revised clearance call as a contributing cause, it is the 11th and very much last in the list! I'd put it much, much higher up there.

That call from ATC could have easily waited and, to me, demonstrates a lack of ATC understanding of what such manoeuvres involve for the aircrew and how long it takes to execute the proceedure. At the very least, ATC should wait till the crew have called "Going Around" which is also effectively the crew saying "OK, I'm ready to talk now!". I may have missed that in the report but it seems they never got the call out.

Also, to terminate the distraction, a swift "Standby!" would have been a good response - but the distraction should not have happened.

I did note the report used the phrase "the primary task of [flying] was momentarily affected [by the ATC call]". Sort of implies that (a) it was a very short call + response and (b) completely misses out the subsequent "OK, so what was I doing before I was rudely interrupted by the radio" moment afterwards which would have added to the delay in getting back on task - which really never happened - hence the result.

Is that a deliberate lifting of the carpet to save ATC embarrassment?

H 'n' H just observes...
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Old 24th Feb 2020, 19:55
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The issue with simply putting the thrust levers full forward to command a go-around on any Boeing is that - unlike Airbus - the thrust lever position always determines the thrust command to the engine. So putting the thrust levers to the firewall will give you max TO thrust for those conditions - not always wanted, needed, or even desirable for a go-around (especially with a light aircraft).
It used to be taught for the PF to keep on hand lightly on the throttles during critical flight phases - especially final approach/landing - to know what the engines were doing, and to guard against a potential autothrottle malfunction. Don't they teach that anymore?
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Old 25th Feb 2020, 01:33
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The issue with simply putting the thrust levers full forward to command a go-around on any Boeing is that - unlike Airbus - the thrust lever position always determines the thrust command to the engine. So putting the thrust levers to the firewall will give you max TO thrust for those conditions

Yes, until you take the hand pressure off the levers. Depending on the A/T mode the levers(thrust) may well retard back to a previous setting will it not?
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Old 25th Feb 2020, 01:52
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Originally Posted by The Banjo View Post
Yes, until you take the hand pressure off the levers. Depending on the A/T mode the levers(thrust) may well retard back to a previous setting will it not?
The thrust lever position will still determine the what the engines do. Which is why it's trained (or at least used to be trained) to keep a hand on them in case a miss-configured autothrottle or malfunction attempts to move them from where the PF wants them to be.
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Old 25th Feb 2020, 06:13
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It used to be taught for the PF to keep on hand lightly on the throttles during critical flight phases - especially final approach/landing - to know what the engines were doing, and to guard against a potential autothrottle malfunction.
Absolutely the correct technique, IMHO.
So putting the thrust levers to the firewall will give you max TO thrust for those conditions - not always wanted, needed, or even desirable for a go-around (especially with a light aircraft).
This is a new concept to me - in the few jet aircraft I have flown, EVERY go-around was flown with TO thrust until level-off. I have never heard of the option of using less than TO thrust for a go-around - what is the PM meant to answer with when you say "Check Thrust"? Not having a go, genuinely interested in this new (to me) idea.
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Old 25th Feb 2020, 06:58
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Originally Posted by josephfeatherweight View Post
Absolutely the correct technique, IMHO.

This is a new concept to me - in the few jet aircraft I have flown, EVERY go-around was flown with TO thrust until level-off. I have never heard of the option of using less than TO thrust for a go-around - what is the PM meant to answer with when you say "Check Thrust"? Not having a go, genuinely interested in this new (to me) idea.
Airbus has a soft GA feature where you select max thrust momentarily, then go back to a lower setting before finally setting climb thrust at the usual altitude. This reduces the rate of increase of both kinetic and potential energy, particularly when light and with a low altitude level off.

My company has made a poor man’s version of this, and it’s a**holes and elbows trying to do all the call outs (6 in all before we get to “positive rate”). Needless to say, I’m not a fan.
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Old 25th Feb 2020, 07:01
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Originally Posted by josephfeatherweight View Post
Absolutely the correct technique, IMHO.

This is a new concept to me - in the few jet aircraft I have flown, EVERY go-around was flown with TO thrust until level-off. I have never heard of the option of using less than TO thrust for a go-around - what is the PM meant to answer with when you say "Check Thrust"? Not having a go, genuinely interested in this new (to me) idea.
We do have a ‘discontinued approach’ procedure in the books, which is used when a G/A is required during earlier stages of the approach, close below or above the missed approach altitude and far away from the MAPt.

Involves leveling of in ALT mode and climbing or descending to the missed approach altitude in Level change or V/S etc.

Safe to say that procedure doesn’t apply to this incident by the way
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Old 25th Feb 2020, 09:14
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Understood - thanks for the explanation - I guess I wasn't really considering the "early missed approach" scenario, more the "missed approach from minima" or low level go-around.
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