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Blind following of flight directors yet again

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Blind following of flight directors yet again

Old 15th Mar 2021, 13:34
  #41 (permalink)  
 
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In some cases, yes. We would need them on for CAT lllB/C for example, to give us higher precision on the ILS, and the yaw bar to follow the runway centreline once landed in low vis.

But if flight directors were only used for the more navigationally critical situations, and not all the tine, then we would all keep our scans polished and our recollection of correct pitch and bank attitudes etc. As far as not knowing if the automatics were behaving, well we would see from the PFD if they were or not, surely?

I realise that currently; turning the flight directors off will affect other systems, for example RNP approaches or the auto-thrust on Airbus FBW. But flight with unserviceable flight directors is allowed in the MEL. I am just thinking aloud about ways to improve our flying skills, and how a small modification might allow this.

I remember years ago on our course to go from the Shed onto the Dash 8, the classroom trainer kept going on about the flight director. None of us knew what he was talking about - no FDs on our Sheds, so we were all raw data flyers, and we thought he meant a guy in an office !!!

Last edited by Uplinker; 15th Mar 2021 at 13:51.
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Old 15th Mar 2021, 14:20
  #42 (permalink)  
 
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Without the FD's you wouldn't know if the automatics are working correctly.’
Assuming that this refers to autopilot (automatics) and the FD, then without assurance that these systems were independent and of equivalent integrity, the use of automation to monitor automation is a very poor practice.
‘Blind checking the blind’.
Without independence or integrity then AP and FD could suffer similar error, e.g common sensor or input failure.
Monitoring must involve independently comparing the autopilot or FD against the aircraft response - the actual flight path, the real world, not as expected or computed.
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Old 15th Mar 2021, 16:29
  #43 (permalink)  
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safetypee, agree with your observation re b. leading b., etc., but, (and perhaps vilas meant this), what is correct, is that the FDs do tell you what the automatics are doing & going to do, and that does require independant confirmation for correctness with other cues & clues contributing to normal situational awareness.
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Old 15th Mar 2021, 17:47
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Without independence or integrity then AP and FD could suffer similar error, e.g common sensor or input failure.Monitoring must involve independently comparing the autopilot or FD against the aircraft response - the actual flight path, the real world, not as expected or computed.
There are three ADRs and yet unreliable speed happens and that's why the pilot is there to take over. I have said it a few times before whether the AP is on or off pilot's scan or monitoring does not change. With AP on AP makes flight path changes with AP off pilot does it himself. In modern Aircraft pilot also has to know the automation well. Nobody denies that pilot must possess basic flying skills but you cannot turn automation into a villain. Better redundancy and automation is also reducing the requirement of very high standard of basic manual skills.
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Old 16th Mar 2021, 10:03
  #45 (permalink)  
 
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"I have said it a few times before whether the AP is on or off pilot's scan or monitoring does not change. "

Should not change, I totally agree, but in some cases we have seen that it does change.

How could we avoid this? Well, perhaps if flight directors were able to be switched off most of the time, then all our scans and recall of correct attitudes would improve, because instead of glancing at a square box over two crossed lines, we would become used to looking at the raw PFD and assimilating and mentally cross-checking any attitude change with what was commanded and intended.

We would have to look at the raw data, even to monitor the automatics, and our knowledge of correct attitudes would become ingrained.

The human brain will always do the easiest thing and it will not maintain something it rarely uses.
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Old 16th Mar 2021, 14:20
  #46 (permalink)  
 
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Originally Posted by FlightDetent View Post

You're reading too much into it, I am not that versed. Facing the simple choice of saying "making wrong decisions" I elected play smart with "not taking the good decisions". At the time of writing it looked reasonable as I tried to convey observed empirical reality that handflying reduces the brainresource to make decisions (in the true meaning you explain agreeably).

...

Agreed! That is exactly why I said NOT TAKING the good decisions.
OK, maybe I read too much into what you meant by decision. But if you're simply using it to say that they didn't do the right thing, then your explanation for why they didn't do the right thing, is that they didn't do the right thing. It's not explaining the behavior, just restating it. And not put forth an alternative to "they can't handle it," which is what I think you were trying to do.

Sorry, now that I noticed you partly try to disagree with the opposite of what I wrote, deciphering what may be relevant in this last paragraph is not compatible with my timezone a.t.m. For the record I never discussed the choice of engaging the AP or not, but the other choices and desicions that need to be solved regardless of automation state, and specifically which of the basic chess-board laouyts (AP=on vs. hand-flown) leaves more spare processing power.
Fair enough, we could have been talking about different accidents (or aspects of same accidents). I've acknowledged that on any given flight, the AP-on chess board layout leaves more processing power.

But isn't it a pilot's job to have the processing power, with AP off, to solve chess problems like "what am I doing to the airspeed by pulling multiple dozens of pounds?" or, "the airplane is banking and I don't want it to" or, "the airplane is descending to a point a mile short of the runway, in plain VMC?" Not as a show-off of pilot prowess, but because pilots are forced to do this by circumstance and it's required to arriv safely. If you agree that that is our job, then how are pilots to achieve this ability?

First thought, your opinion: If [email protected] was hypothetically flown remotely by a remote pilot UAV-style, would the captain at chair 0A / 0B had better chance to a) notice b) evaluate correctly c) take preventive action against the speed-loss (combined)? Compared to himself flying manually at the time.
Really the more relevant scenario is that the remote link failed in the middle of the approach and the row zero passengers suddenly had to start flying.
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Old 21st Mar 2021, 00:18
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Originally Posted by vilas View Post
Without the FD's you wouldn't know if the automatics are working correctly. That's the reason in an Airbus doing a NPA without vertical guidance the FD is kept on. The bird just floating without a reference will make no sense.
What would prevent you from knowing if the automatics are working correctly? (Talking in generalities here, not some particular mode on a particular airplane where there may be no raw data displayed and the FD guidance would be the only possible guidance)

You are able to monitor if it's maintaining the altitude, or vertical speed, or heading, course, GS, etc., that is programmed and intended.
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