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Old 16th Sep 2016, 20:34
  #1578 (permalink)  
RAT 5
 
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Interesting point and it caused me to reflect on something most of us do by intuition; car driving. This is not expressing an opinion, but opening a human performance discussion.

Steering: if we want to turn gently we deflect, and HOLD the deflection to complete the turn. If we wish to alter the radius we alter the deflection and receive a change in force feedback. In hydraulic controlled a/c we deflect ailerons and when the BA is reached we centralise; AB perhaps more so than Boeing. At least we move the relevant control. Changes in forces are less than cars.
With changing thrust in a car we deflect the accelerator pedal, more or less and keep it deflected. Auto-Thrust in Boeing yes, in AB no. With braking we deflect the pedal and the stronger the braking the harder the deflection and force feedback. In all these actions, car or a/c we have feedback to our tactile sense and follow it up with visual senses and g forces. The car doesn't do pitch, but in the a/c we deflect the control and centralise, AB, or manually trim out the force, old Boeing.
The point being, in a car, if we want to do something we deflect a control and feel it move and receive various forms of feedback. Even in CRZ Control we can feel the accelerator move automatically with our foot and see the RPM change.
I'm not an FBW pilot, but I wonder if we've removed too much of the instinctive tactile feedback we receive in an a/c and make it so different to something we do every day instinctively without conscious effort. Is removing the power pitch couple and improvement in letting us know what the a/c is doing?
The other argument is that the a/c is designed to be flown more via automatics than manually. Once airborne, and until flare, it can be purely a monitoring role: i.e. the feedback is only visual with some g thrown in. Is this instinctive? In other words would we be better off in some phases of flight being more manual and less automatic? Being trained about the automatic systems & understanding the automatic systems in a stressless class room is one thing, but under stress, or startle, would instinctive reactions be safer? This question about AT over dependancy, even in manual flight is a case in point. If it is manual thrust, with pitch couple (feedback effect) there is no doubt what is necessary. Does this not remove confusion; because it seems to be confusion about an automatic system that has caused various crashes. Remove the doubt.
I've only flown an AB sim for 1hr. The role control was not instinctive; i.e. the nudge/centre/nudge/centre. It needed strong concentration on PFD. From some I've spoken to it's not so easy, in the early days, in strong gusty X-wnds as a conventional column e.g. B757/767/737. I can not comment on B777. The AB pilots will be able to inform us much better, and B777 as well. I hear it can be trained and you can 'get used to it', even the non-moving TL's, but from a human factors perspective is the reduced tactile feedback and reduced 'instinctive behaviour' an improvement & safer for manual flight?
I know the techies are trying to persuade us about automatic cars. I am sceptical . They might work on motorways specially designed for nose to tail max flow at constant speed with no lane changes = 4 wheel trains in convoy; but in towns & cities? Hm? Our instincts will still be needed.
I'm sure there will be strong opinions from the old & new, standard hydraulic & FBW, AB & Boeing. I've read that people love one or the other, or have no problem with either. My query is about it being instinctive or not. Do we as pilots not rely on instincts subconsciously? If, during critical phases on manual flight, everything has to be scanned, monitored, interpreted e.g. FMA to know what is going on, is there not a tiny delay in digesting the information and deciding on an action, or even a possibility of confusion and even further delay on action? I once jump seated during live base training of a DC8 captain trying to fly circuits in B757. The SOP was to use FD's and call for MCP changes. He was all over the sky and the TRE was ready to bin him as a non-pilot. I suggest switching off the FD's so he didn't have to think, speak, follow. He went back to basics & instincts in silence and flew it on rails.
I know there are many who believe we are here & now in 21st century not in steam driven jets of 80's. True; but does that mean that we are operating the new technology in the best manner, or that the new technology, just because it is hi-tech, is automatically better in every respect? We haven't changed the human very much but we sure have changed what they have to interact with by huge amounts. Do we have the best combination? Have we moved too far & too fast?
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