PPRuNe Forums - View Single Post - Computers in the cockpit and the safety of aviation
Old 27th Jun 2011, 20:36
  #163 (permalink)  
Young Paul
 
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I agree that there's a need to be an all-round pilot. What I'm challenging is how great the role of "traditional" skills and "traditional" behaviour of the aeroplane should be in this matrix.

To take traditional aeroplane behaviour to start with. I am quite happy (even as an Airbus pilot) to say that FBW was placed in a life-critical application ten years too early. Now, however, on the back of 30 years of practice, I don't have any significant doubts about it. The designers had to make decisions: should we have manual reversion? Should we be able to fly with flight control computers all off? Should there be tactile feedback in the control system? Whilst the decisions they made at the time may have been ambitious, I don't think that history demonstrates they were wrong. Where there have been hull-losses of fbw aircraft, I don't think you can really show that it was an issue with the computers. At worst, it was an issue at the man-machine interface, which highlights the real safety issue - that is, the human factor - people not using the system properly. So in what circumstances do we need to know that we can fly it in the "traditional" way? I think BA have gone too far in saying that you can't fly without the ... whatever it is they say you can't fly without. Autothrottle? But all airlines have to make a decision which can be justified to the regulatory authorities.

Now traditional skills - the ability to switch off all the automatics and fly by hand. In what circumstances is it necessary? I flew with a technically switched-on fo the other day who knew that you could get the best descent out of an A320 by switching the automatics off. That was safely done in VMC. But the number of times when I've been put in a position in many years where this made the difference between a landing and a go-around is - well, one. If you're high, you can ask for extra miles. Or go around. Or you can plan things from further back to make sure that you reach the gate. And the price of switching all the automatics off voluntarily is that unless you're very careful, you're taking not only those protections out, but also the inclusion of your fellow-pilot in the monitoring loop. Much better as a rule, surely, to work within the constraints of the automatic systems.

What about technical issues or multiple system failures or lightning strikes coupled with autopilot disengagement? Again, whilst as pilots we should be able to cope with this, would it be proportionate to gear our training towards a once-in-a-flying-career combination of failures? To be honest, when everything goes wrong, none of us really knows if we'll be successful when we step up to the plate. Every famous air incident you can think of - in each case, the pilots didn't know what they were going to be facing when they went to work in the morning. In all, arguably, they were heroes - in some, they saved lives, in some, they didn't. But it's a bit like the engine failure at v1, thing - the danger is that you prepare for the "worst" case, and get very good at managing that, but don't know how to cope with anything less than extreme. We really don't want people switching autopilots and flight directors off because one of the flight control computers has failed, do we? But I think there's a risk of that. Again, I've heard of experienced captains, doubtless very good at handling the aeroplane, who have used their superior handling skills to escape from encounters with CBs that good airmanship ought to have kept them away from in the first place.
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