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Boeing incidents/accidents due to Thrust/Pitch mode mishandling

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Boeing incidents/accidents due to Thrust/Pitch mode mishandling

Old 12th Oct 2018, 13:41
  #41 (permalink)  
 
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Originally Posted by aterpster View Post
Not doubting he said that. But, he was pulling that assumption out of his ass.
I don't see that. A commercial aircraft needs to be safely and reliably operated by the least competent pilot on the seniority list, wouldn't you agree? Designing it under any other assumption would be negligent.
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Old 12th Oct 2018, 16:35
  #42 (permalink)  
 
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Originally Posted by Vessbot View Post
I don't see that. A commercial aircraft needs to be safely and reliably operated by the least competent pilot on the seniority list, wouldn't you agree?
Absolutely NOT! What if an operator decides to hire a blind pilot? Or a pilot with mental disorders? Never never let the operator define the competency level of the pilots it hires. Commercial aircraft need to be designed to a specific competency level and then the operator and regulators must ensure that it hires and trains pilots to at least that competency level or better. Designing aircraft for low competency pilots would be negligent.
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Old 12th Oct 2018, 16:56
  #43 (permalink)  
 
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No matter who is hired, by definition someone has to be the least competent. Your position is the same as "our amps go to 11." It's one louder, you see...
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Old 12th Oct 2018, 17:01
  #44 (permalink)  
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KenV

You might want to google “window of circadian low” or maybe any study into the effects of fatigue. A competent pilot who hasn’t slept because he/she has operated a flight at the limits of allowable FDP might be a tad sleepy. Of course I’m drifting in Human Factors here. Tut tut. Let’s hark bark to the good old days when no one screwed up. You know before the “children of the magenta line”.
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Old 12th Oct 2018, 18:41
  #45 (permalink)  
 
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Not incompetent as such, but do we have to design for the "99 percentile bad" pilot, which may not be far removed from incompetent... Sadly, in many cases this means making the system "less good" than we otherwise could if we didn't need to account for a sub-par pilot.

Another part of the problem is pilots switching between aircraft makes. There is a certain logic to the way Boeing systems work - and it doesn't change all that much between the various Boeing models. Fly Boeings your whole life and it all makes perfect sense. Airbus has a certain logic as well that is pretty consistent between the various model, and it makes sense to the people who have only flown Airbus. But the Boeing logic is different than the Airbus logic. Which one you think is better is largely dependent on which one you 'grew up with', both work, but they are not completely compatible with each other.
It's sort of like driving on the right or on the left - both work, both have people that think their way is better. I grew up driving on the right - it's what comes natural to me. I've driven on the left for many thousands of accident free miles when in other county's (mainly the UK and Australia) - it's takes more attention and is hence more fatiguing - but it's not all that bad so long as things don't go seriously wrong. But I also know and fear that, faced with an emergency situation where I need to take split second action, my instinct will be to 'go right' - which if I'm driving on the left could be the exactly wrong thing to do.
While it has gotten little discussion here, I'm firmly of the belief that Asiana was in no small part due to the pilot transitioning from Airbus to Boeing and that's why the aircraft systems didn't behave the way he expected.
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Old 12th Oct 2018, 19:37
  #46 (permalink)  
 
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Originally Posted by KRviator View Post
Respectfully, I think you've both missed the point. I guess you would both argue that AF447 was solely the result of the crew, rather than the fact they lost the airspeed in the first place...

Yes, the crew screwed up (in both AMS and AF447...), in a massive way. I am not disputing that fact at all, nor trying to absolve them of that claim.

But...

Amsterdam was not, in itself, the fault of mode confusion, or automation dependency. The crew recognised the decaying speed, and that the throttles retarded automatically. They then pushed them up, and believed (and this is where their lack of systems understanding failed them) they would stay there - and through lack of basic airmanship, let the speed decay to a point where the accident was inevitable.

Consider the case of Scandinavian 751. Engine surge on the initial climb, pilot does the right thing and reduces power. But the autothrottle restored power on the engine, resulting in dual engine failure and the ensuing crash. The pilot knew nothing about that 'feature', nor did the airline. Is it still their fault for not noticing the increasing power? The moral of the story is, pilots screwup certainly. But rarely does that, in itself, cause an accident and it is fatally simplistic to simply lay the blame for a prang at the feet of the crew.
I fly the A 320, quite a few years ago as a first year fo, in a turn to final, I got the “speed, speed, speed” warning. Unsure of how to proceed, I looked to the left. He said “my controls”, realized the automation wasn’t aware we were trying to land, and said “your controls if you want them “. The speed warning is there to tell you your energy is decreasing, which is what I was trying to do. It took a good long read of the manual after landing to realize why it happened. Shortly after my upgrade I flew a few times with the autothust deferred, and I realized I had gotten very used to it working, so I made it a point to not use it on both TO and landing whenever possible. There seems to be a lot of companies/authorities that feel keeping the automation on the highest level is always preferred. Luckily for me, my company feels proficiency is important. When I say the pilots were at fault, it is part of a bigger problem. If the company/authorities won’t let the pilots fly manual it might prevent some accidents, but it will definitely cause other accidents. Having said all that:
AF 447, the only instrument that failed was airspeed, and only for the first minute. The second officer kept pulling back even after being told not to by the FO. The FO never took control when he clearly should have. For the record, I hate the Airbus design, you really can’t see what your colleague is doing.
AMS, the throttle moved back RIGHT AFTER THE FO MOVED THEM UP, the training captain should have recognized the automation wasn’t going to work.
I haven’t read the whole report on SAS, but it sounds similar, he pulled power, power came back up, he did nothing.
As pilots we are the last line of defense against all the deficiencies in airplane design, SOPs, rules, ATC errors, etc.. does that mean we are always the problem? No, but we need to be able to recognize, react and recover when something goes wrong. Failing to do so will get you killed, and criticized on PPRuNe afterwards.
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Old 12th Oct 2018, 19:45
  #47 (permalink)  
 
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Originally Posted by FlightDetent View Post
tdracer, that's probably not worded to describe precisely the SFO accident. Anyhow the energy level was tricky. Intercepting a standard 3 deg profile from above, with a rather low-and-close geometrical intersection point is a beast. Your mind is firmly set that you are hot and high, so you WANT idle thrust....

and then

... In fact, as you intercept the G/S, heaven forbid the AP or pilot pulling up to capture it - oh wait, there is no other way - the A/C if still with idle thrust is in a SEVERE low energy state. Add to that a bit more pull to recover the duck-under (no matter A/P or human) and you have a 7n7 with a 6-8 degree DOWN trajectory vector, full landing flap with L/G down and 5 deg NU pitch to recover the profile and it is an extremely high drag configuration. The inertia is massive.

If not anticipated it all happens very fast and the recovery N1 is in the low 80s. Feel free to ask how I know.

Another trap is how un-common it is. These days especially long-haul it is ILS to ILS and stable-coupled from 15 NM. And guys get about 2 landings a month each. The chances of recognizing not only that the situation is wrong, but how quickly and deeply bad it is about to become are practically nil. And then you are left with the reactions. Why theirs came late is elementary HF.

In this respect both AMS 737 and SFO 777 wouldn't have happened if it was not for the intercept from above to begin with, I am quite convinced.
You are right intercepting from above is recipe for trouble. Yesterday I saw an 18 check airman do it wrong. I don’t fly the 777, is there no way to have the AT armed to speed mode while in idle descend?

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Old 12th Oct 2018, 19:46
  #48 (permalink)  
 
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Originally Posted by Capn Bloggs View Post
I was being sarcastic. That diatribe from Switchbait is one of the bigger loads of nonsense I have read.
not sure if I agree....
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Old 13th Oct 2018, 02:55
  #49 (permalink)  
 
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Hans, I was arcing up about this dinosaur attitude that you're pilots and pilots should be able to cope if, for example, the ATS doesn't wake up. I wonder what their attitude is to GPWS and TCAS; enhancements in technology to save dumb pilots. Or are they different to a fundamentally flawed ATS design that will catch out dumb pilots?
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Old 13th Oct 2018, 04:21
  #50 (permalink)  
 
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Excuse my interruption but here are a few other bits and pieces of studies and incidents for the Original Poster:
Carry on...
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Old 13th Oct 2018, 08:01
  #51 (permalink)  
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Is it my imagination or is it reasonable to presume that some of the pilots posting here don't have one hand on the control column and one hand on the throttles at all stages of the approach, including autolands? Just the way some posts have been written perhaps.
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Old 13th Oct 2018, 19:04
  #52 (permalink)  
 
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Originally Posted by hans brinker View Post
The only reason we still have pilots is for when shit hits the fan, anything else can be automated.


Yes. But ironically due to the near-ubiquitous normal-case automation, these pilots have lost the ability to fly competently and confidently in normal situations... much less when the shit hits the fan. The only way for a pilot to justify his existence is to maintain that ability. Without that, we're already riding in drones.

The FO pushed the throttle up, let go, it went back to idle, and for the next 100 seconds all 3 of them sat there while the thrust was at idle, and the speed dropped to 83kts, 40kts below Vref.
Imagine the quote is "The FO put the yoke where he wanted, let go, it went back to the wrong place, and for the next 100 seconds all 3 of them sat there while [etc.]"
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Old 13th Oct 2018, 19:31
  #53 (permalink)  
 
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Originally Posted by parabellum View Post
Is it my imagination or is it reasonable to presume that some of the pilots posting here don't have one hand on the control column and one hand on the throttles at all stages of the approach, including autolands? Just the way some posts have been written perhaps.
I think you are probably correct. I most certainly do keep my hands on the controls during those stages. Then again I come from GA and Turboprops, the traditional route as it were. Where you learned to fly properly before you got near any automatic aids.
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Old 13th Oct 2018, 22:35
  #54 (permalink)  
 
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Originally Posted by parabellum View Post
Is it my imagination or is it reasonable to presume that some of the pilots posting here don't have one hand on the control column and one hand on the throttles at all stages of the approach, including autolands? Just the way some posts have been written perhaps.
I've been in the flight deck as an observer for countless flight tests and simulator sessions. Every single time, the pilot flying would leave one hand resting on the throttles during final approach/landing. Most of these were Boeing flight test pilots (who are generally really good stick and rudder types), but some were FAA/EASA, and a few were operator line pilots (when we did remote flight tests at an operator, they often had a rule that a company pilot had to be flying - with the Boeing pilot in the other seat).
I'd just assumed that was trained as SOP for Boeing aircraft. Also part of the reason why I think the PF being a recent transfer from Airbus was a contributing factor on Asiana at SFO.
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Old 13th Oct 2018, 22:50
  #55 (permalink)  
 
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Originally Posted by tdracer View Post
Also part of the reason why I think the PF being a recent transfer from Airbus was a contributing factor on Asiana at SFO.
Interesting thought. In the same vein I took a quick look at the accident report of the Turkish AMS crash to see the crew's backgrounds, but it was all only 737 type ratings. Any bets on whether they habitually kept their hand on the throttles? (Not to speak of habitually flying the plane sans automatics). Lazy habits build a fatal baseline, as allowed by the automation regardless of type.

Same as the Emirates crew that attempted the idle thrust goaround in Dubai.

Last edited by Vessbot; 14th Oct 2018 at 01:54.
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Old 14th Oct 2018, 10:27
  #56 (permalink)  
 
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tdracer

You are spot on.
The non flying hand belongs on the TL ( minus V1 to ca 400 feet on T/o) for tactile feedback.
Very important on the 738 when trying to slow down on a tailwind approach and or a steeper then 3` glide when heavy.
Now for the Asiana:
First Q:
" How many pilots does it take to trash an aircraft?"
A
"Usually 3, One being an instructor and or super senior"

I am on my first zigar and second coffee , so not quite awake this balmy Sunday morning, so my numbers might be wrong from memory:
The Captain Candidate had 8000 hrs and ALL on A320 and they were sitting him direct into the LH seat to command a 777. He had less then 3000hrs command.
That is pure madness from the Company and the local CAA, me thinks.
THE direct cause of the accident.
As mentioned before if THIS was a challenging approach , what about the one Murphy had lined up the first week after line release , on that dark and stormy night , with the toilet on fire!
A systemic fail from the company with at least two marginal crew with that a lack of self preservation.
Blame Boeing!
Why not, they should not have sold it to them in the first place?

Regards
Cpt B
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Old 14th Oct 2018, 10:58
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MyBad, just checked the NTSB report.
He had 9700hrs total since 1993 and plenty of 737 and some 747 time.
A320 command for the last little while. Still not a good idea as it turned out!
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Old 14th Oct 2018, 13:43
  #58 (permalink)  
 
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Any bets on whether they habitually kept their hand on the throttles?
​​​​​​There's a good video on YouTube from the flight deck showing the 787 taking part in an air display.

No one has their hand on the thrust levers, so if Boeing don't consider it important then it's unlikely to be of relevance to this incident.
​​​​​​
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Old 14th Oct 2018, 14:03
  #59 (permalink)  
 
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Boeing is hardly going to put in it's FCTM "keep your hands on the throttles"!

From the same company that designed the ATS to stay dormant while the aeroplane crashed due to slow speed...
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Old 14th Oct 2018, 14:10
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Originally Posted by Fursty Ferret View Post


​​​​​​There's a good video on YouTube from the flight deck showing the 787 taking part in an air display.

No one has their hand on the thrust levers, so if Boeing don't consider it important then it's unlikely to be of relevance to this incident.
​​​​​​
There's less of a need to react quickly when you're zooming around at high speed, plus your second hand is needed on the yoke when you're wrestling a pig through the sky anyway.

But fast forward to the end to see where his hand is during a phase of flight with a higher "relevance to this incident."
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