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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 25th Feb 2020, 18:23
  #41 (permalink)  
 
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Boeing has two go around settings (I'm speaking widebodies, but I suspect the 737 is more or less the same). One push gives a basic go-around thrust for (IIRC) 2,000 ft/min climb, a double push gives max rated thrust.
In the pre-FADEC era, or if operating FADEC in hard Alternate mode, pushing the throttles to the firewall can result in a major overboost of the engines (I know of a few stories where they pilot forgot they were in Alternate mode or EEC OFF - did you know a JT9D can reach 2.0 EPR near sea level ). So while it should be safe to firewall the throttles with FADEC in normal mode, it would require a different procedure for Alternate mode or pre-FADEC aircraft (recall there are 767 operators that have both FADEC and non-FADEC aircraft) - obviously undesirable.
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Old 26th Feb 2020, 03:36
  #42 (permalink)  
 
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The capt was flying the HUD.
That comment brought back a memory of watching a MD80 (stretched DC9) landing on the 5600 ft length runway on Nauru atoll, Central Pacific around 1984. I was a B737 pilot at the time and had operated out of Nauru many times. There are no overruns at the end of the only runway 12/30 - only massive rocks which would tear open any aircraft.

The MD 80 seemed quite high over the fence compared to a 737 approach using T-VASIS. There was a long float after initial touch down which was well into the runway. The aircraft stopped at the extreme end after heavy braking. It was a close thing.

I later talked to the captain of the MD80 which was on a Good-Will flight around the world. Neil Armstrong the astronaut was on the aircraft.
The captain said he used the HUD for landings. Certainly in this case, the HUD nearly pranged him and I saw no value in using a HUD on a sunny day on a short runway where there were ample visual cues and a T-VASIS for glide slope guidance

While I can understand that today's HUDS are much more sophisticated than in 1984, I still question it's use when it is simply an aid to landing but yet has its limitations. Like the Fly Dubai 737 go-around accident where I believe there was evidence the PF was locked on his HUD. In following its guidance for the go-around at night the PF flew the 737 into a spiral dive from a steep go-around climb. I understand the HUD was not designed for such an extreme manoeuvre but the company demanded its crews use the HUD for all landings.
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Old 26th Feb 2020, 19:39
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Originally Posted by Centaurus View Post
That comment brought back a memory of watching a MD80 (stretched DC9) landing on the 5600 ft length runway on Nauru atoll, Central Pacific around 1984. I was a B737 pilot at the time and had operated out of Nauru many times. There are no overruns at the end of the only runway 12/30 - only massive rocks which would tear open any aircraft.

The MD 80 seemed quite high over the fence compared to a 737 approach using T-VASIS. There was a long float after initial touch down which was well into the runway. The aircraft stopped at the extreme end after heavy braking. It was a close thing.

I later talked to the captain of the MD80 which was on a Good-Will flight around the world. Neil Armstrong the astronaut was on the aircraft.
The captain said he used the HUD for landings. Certainly in this case, the HUD nearly pranged him and I saw no value in using a HUD on a sunny day on a short runway where there were ample visual cues and a T-VASIS for glide slope guidance

While I can understand that today's HUDS are much more sophisticated than in 1984, I still question it's use when it is simply an aid to landing but yet has its limitations. Like the Fly Dubai 737 go-around accident where I believe there was evidence the PF was locked on his HUD. In following its guidance for the go-around at night the PF flew the 737 into a spiral dive from a steep go-around climb. I understand the HUD was not designed for such an extreme manoeuvre but the company demanded its crews use the HUD for all landings.

I remember the MD-80 HUD quite well. For approach there was an ILS mode, which gave the same guidance as the FD, albeit with a dot to aim for rather than needles. Using this and Autoland we could fly Cat111 to 20ft RA min, as the GA mode counted as a backup for the AP channel.
Then there was a visual mode. I never really liked it. You aimed an element in the display at the desired touchdown point and when around 50ft RA it gave you a flare to a very soft landing. While concentrating on the guidance it was easy to stop concentrating on the visual landing clues. I could imagine folk might use it to give a VIP a soft touchdown but I preferred to use the Mk1 eyeball and get down at the right spot.
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Old 29th Feb 2020, 01:16
  #44 (permalink)  
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Originally Posted by Dave Gittins View Post
Would removing the mandate to use auto throttle at all times have avoided this one ?
I am quite sure, that without automation we would have more accidents. Unfortunately. There are way too many below avarage pilots around and the industry has to respond for this fact. Unfortunately.
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Old 29th Feb 2020, 02:23
  #45 (permalink)  
 
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Originally Posted by G-V View Post
There are way too many below avarage pilots around...
The oft-quoted 50% comes to mind. Complemented by the 50% above average.
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Old 29th Feb 2020, 08:07
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Why would you ever want more than 2000fpm on a go around ?


This is one of many well thought out features on the 757 / 767


One of the biggest challenges on go arounds (which we rarely do) is an excessive rate of climb approaching a low altitude level off mandated on the missed approach and / or by ATC


Rarely do you ever need more than that, a positive but smooth thrust increase to 2000fpm and with far less pitch coupling is good strategic planning far less likely to result in an altitude overshoot


I remember selecting go around in the MD 80 at on a few occasions, with its crude autothrottles it was such a massive thrust increase and pitch change it was all you could do to stay ahead of the aircraft and level off when required


If you need more power itís there, otherwise I think itís a fine system

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Old 29th Feb 2020, 08:52
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2000 fpm in a G/A

Anyone who ever performed a Go-Around on a light A310-300 will appreciate exactly why 2000 fpm is a Good Thing!
7B
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Old 29th Feb 2020, 14:54
  #48 (permalink)  
 
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Originally Posted by 777boyo View Post
Anyone who ever performed a Go-Around on a light A310-300 will appreciate exactly why 2000 fpm is a Good Thing!
7B
Amen to that one!

The 'bus goes to full TOGA and doesn't throttle back in the climb. With a short local captain holding the yoke and a seat rail coming unlatched on the pitchup it makes for an impressive airshow.
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Old 29th Feb 2020, 14:57
  #49 (permalink)  
 
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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..................
Without wishing to turn this into Airbus vs Boeing, the Boeing auto-thrust seems a peculiar beast and I agree with Fursty on this.

In manually flown Airbus FBW G/A; you push the thrust levers fully forward - click, click - with your inboard hand. Very little effort is required and you will not over-thrust the engines. Pull gently back on the joystick, needing only the strength in your outboard wrist, to set +15į pitch. You could then let go with both hands and the aircraft would stay in the attitude it was put.

I only know the 737: the yoke requires arm muscles to pull it back - or to push it to counter the power/pitch couple. To guide in pitch accurately, a pilot might want to use both hands on the yoke to give finer control, and to trim in pitch or to add strength if the aircraft is initially mistrimmed. So s/he will want to take their inboard hand off the thrust levers as soon as possible and therefore has to rely on the TOGA switches and PM to set thrust. This takes away their haptic feedback of where the thrust levers are, at a time when their attention will be focussed on the PFD to check pitch and ROC.

Not having flown it; Would a 777 pilot want to put both hands on the yoke as soon as possible?
Is there a power/pitch couple on a 777 when manually flown?
Does 777 have auto pitch trim when in manual?
Does the 777 yoke stay where you put it if released, or would it return to trimmed attitude?

A general point about automation; Yes, we could all fly around fully manually all the time. Then we would no doubt all be able to physically control the aircraft very well, despite their various foibles. But it is knackering, so FTLs and flying during the WOCL would have to change. RVSM, LVP and RNAV approaches would not be possible and Long-haul would need several crews on each aircraft.

So we need automation, and this is not a weakness - no more than driving a car with an auto gearbox and cruise control/speed limiter. On the contrary; it frees pilots to be more vigilant about the overall flight. The challenge is that automatics need to be designed to work properly and intuitively with human beings. Airbus FBW comes very close to this, I don't know about Boeings or other types?
.

Last edited by Uplinker; 1st Mar 2020 at 08:53. Reason: typo
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Old 1st Mar 2020, 08:33
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Too much automation biting pilots in the arse again.
This would never have happened on the VC10.
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Old 1st Mar 2020, 10:06
  #51 (permalink)  
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Originally Posted by Stanley Eevil View Post
Too much automation biting pilots in the arse again.
This would never have happened on the VC10.
no, but something else would likely have happen then, .
Only 54 VC10 buit, 9 accidents , (OK 3 were loses due hijacking ) but still 6 valid .
B777 production is around 2000 with 9 hull losses , to match the VC10 there would need to be around 200 B777 hull losses....
other times...

Last edited by ATC Watcher; 1st Mar 2020 at 12:16.
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Old 1st Mar 2020, 11:13
  #52 (permalink)  

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Not having flown it; Would a 777 pilot want to put both hands on the yoke as soon as possible?
Is there a power/pitch couple on a 777 when manually flown?
Does 777 have auto pitch trim when in manual?
Does the 777 yoke stay where you put it if released, or would it return to trimmed attitude?
Both hands not required although the control forces are clearly greater than that of an Airbus sidestick.
On both the B777 and B787 there is no pitch/power couple, the Primary Flight Computers take care of that.
Pitch trim is manually applied and is slightly different in concept from other Boeings in that the aircraft is trimmed to a speed. When in trim and at that speed the aircraft will remain at whatever pitch atttude the pilot selects. If the speed increases or decays the aircraft will not be in trim.
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Old 4th Mar 2020, 10:24
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Thanks Mr Mouse.

So......I presume then that a go-around in a 777 is not particularly challenging in terms of yoke forces and controlling the pitch and the trimming? so it seems weird that PF and PM both missed noticing that the thrust levers were not pushed fully or nearly fully forward? And that the engines had not markedly increased N1/EPR.

As I say, I've never flown the 777.
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Old 4th Mar 2020, 13:50
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In following its guidance for the go-around at night the PF flew the 737 into a spiral dive from a steep go-around climb
Wasn't a spiral
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Old 4th Mar 2020, 20:03
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Originally Posted by Uplinker View Post
Thanks Mr Mouse.

So......I presume then that a go-around in a 777 is not particularly challenging in terms of yoke forces and controlling the pitch and the trimming? so it seems weird that PF and PM both missed noticing that the thrust levers were not pushed fully or nearly fully forward? And that the engines had not markedly increased N1/EPR.

As I say, I've never flown the 777.
Uplinker - since the 777 is FBW, the yoke forces are artificial (generated by the FBW s/w). By design, as long as you are near the normal flight envelope, the yoke forces are very benign. As I've posted previously, Boeing teaches (or at least used to) the PF to keep one hand lightly on the thrust levers during the critical flight phase of approach/landing so the PF knows the A/T is active and doing what it should.
However if the aircraft is significantly outside the normal flight envelope, the forces increase - again by design - as a sign that you are somewhere you probably shouldn't be. During the Asiana 777 SFO investigation, John Cashman (one time 777 Chief Pilot) testified that the yoke force required to keep the nose up at such critically low airspeeds would have been around 80 pounds - well beyond what most pilots could do with one hand - making it painfully obvious that the Boeing recommended procedure of 'following' the thrust levers with one hand wasn't happening.
Personally I think the biggest lesson learned out of the Asiana SFO crash was that more training should be mandated for pilots switching between Airbus and Boeing (or visa-versa) to account for the fundamentally different flight deck philosophies...
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Old 5th Mar 2020, 08:53
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Remember that the control of the aircraft always has priority... the same goes during go-arounds.

We are again and again told that the go-around procedure is a high workload situation for airliners, hence we're also told not to talk to, or give unnessecary instructions to aircraft executing a go around.

When it comes to wind shear, it is, or can be, characterized as an unusual situation, since we don't expect aircraft to follow a missed appraoch.... most procedures calls for climbs straight ahead at full thrust encountering such, risking overshoot of missed approach altitudes and deviation from tracks.

So from my point of view, and probably most ATCO's now a days, aircraft going around... give them time... don't expect them to do at described.... keep the all the "unusual situation" accronyms/abbreviations in mind, ASSIST/RISC/TAS/SSSS etc. etc.

Not handling a go-around as an emergency, just being a bit cautious with them.
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Old 5th Mar 2020, 10:54
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Hi tdracer

Originally Posted by tdracer View Post
Uplinker - since the 777 is FBW, the yoke forces are artificial (generated by the FBW s/w). By design, as long as you are near the normal flight envelope, the yoke forces are very benign.............However if the aircraft is significantly outside the normal flight envelope, the forces increase - again by design - as a sign that you are somewhere you probably shouldn't be.....................the yoke force required to keep the nose up at such critically low airspeeds would have been around 80 pounds - well beyond what most pilots could do with one hand..........
Strange to engineer a system that way. You have hydraulic power, you have FBW, why make the controls hard to hold accurately? - just design the FBW to protect the aircraft without making it hard to fly.

I personally find it awkward to hold significant force on a yoke and accurately control pitch, and have to trim as well - with just one hand. I would want to get both hands onto the yoke, hence my earlier questions.


My bolds

Last edited by Uplinker; 5th Mar 2020 at 13:11. Reason: Clarification pruning.
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Old 5th Mar 2020, 22:09
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Originally Posted by Uplinker View Post
Hi tdracer



Strange to engineer a system that way. You have hydraulic power, you have FBW, why make the controls hard to hold accurately? - just design the FBW to protect the aircraft without making it hard to fly.

I personally find it awkward to hold significant force on a yoke and accurately control pitch, and have to trim as well - with just one hand. I would want to get both hands onto the yoke, hence my earlier questions.


My bolds
The yoke forces on the 777 are intended to mimic what you'd feel in an old fashioned cable controlled aircraft (the 787 is similar). As you pull into a stall, the yoke force need to keep pulling into the stall increases rather dramatically. This gives very strong, tactile feedback of what you and the aircraft are doing - and it's required by the regs (I assume Airbus managed to get an exemption to those regs since in Normal law you can't go there - of course in Direct law you can, as was demonstrated so dramatically and tragically on AF 447).
This requirement was also the genesis of MCAS, since on the 737 MAX those big engines negate the increase in stick force required to pull into a stall.
That the ASIANA pilot didn't know or recognize that having to pull back so hard meant something was very seriously wrong is a big black mark against the AB to Boeing training he received.
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Old 8th Mar 2020, 12:04
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The report won't download for me any more, so I can't check the details, but I wonder why neither pilot noticed that the engines were not spooling up?

Airbus non-moving thrust levers are often criticised, but at least they mean you must always look at the N1/EPR gauges to see what is going on, and this becomes an ingrained part of an Airbus FBW pilot's scan.

Why these pilots did not do so is an interesting question. It seems to me that the moving thrust lever philosophy has some flaws. There have been accidents, such as the 777 crash into SFO, where the levers did not move despite the lack of aircraft energy needing them to, but this was missed.

I wonder if they are sometimes used as a proxy for the N1/EPR gauges, leading to a lack of scan? This is usually not a problem, except when the pilot is expecting the levers to move without further contact, after the TOGA switch is pressed, and the pilot's attention is elsewhere. With FADECs, there is surely no need for a TOGA switch - you could simply push the levers fully forward, and the FADECs would prevent any excedences.

Last edited by Uplinker; 8th Mar 2020 at 12:42.
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Old 8th Mar 2020, 13:30
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SOPs
unfortunately for your rant, it is not backed up by the facts. If you read the report it is quite clear that the “long landing” automatic call out came after the go around had commenced.
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