Originally Posted by
exeng
About as sensible as if no overide is pressed an input by the same amount in the same direction doubles the input, or if in the opposite direction negates the original input. Remember Hamburg.
Aye, but if used and co-ordinated correctly you can get double the roll rate, which could be useful in an escape maneouvre, or if you see your opposite number doing something that doesn't look right you can negate their input before taking control.
I flew with one of our colleagues back in LGW days on the 737 who twice in two trips on a xwind landing put aileron in the wrong way. Frightening yes - but at least I could see what was happening and correct it before the inevitable - don't think that would have been possible on any Airbii.
Well, you could *see* it happening on a FBW Airbus (you have an ADI in front of you after all), that's never been the problem - the complaint has always been about *tactile* feedback. The thing is that tactile feedback used to serve multiple purposes when controls were directly connected to flight surfaces - you could feel how the surfaces were responding, you could feel what the other pilot was doing and assist if necessary (indeed you could also put more welly behind the maneouvre). But in todays modern world of hydraulically-controlled surfaces with no manual reversion you're down to being able to feel the other guys inputs, plus whatever the q-feel system is telling you. In a lot of cases this is nothing to be sneezed at, but in some cases it can give a false impression of having an effect on the flightpath when in fact you are not. UA232 was an exemplary display of CRM and aircraft control, but one of the interesting factors was the captain and co-pilot forcing their yokes forward and to the left, long after it was obvious that it was having absolutely no effect.
Airbus's philosophy was based on the idea that when going by the book, only one pilot should be manipulating the flight controls at any one time *except for extraneous circumstances* in which they designed the sidesticks to act in the same manner as the yoke, but by summing the inputs algebraically rather than by respective force. Backdrive was considered and ruled out because it added extra weight and complexity (complexity being the main issue), as well as causing extra problems in the event of systems failure or maintenance errors (e.g a cross-wired sidestick on one side).
Still the bus does have some good points like terrain escape which in my opinion is better than any Boeing, 777 included.
As always, there are usually positives and negatives to any differences in design philosophy, and to say that one is objectively better than another in all aspects is not only foolish, but tiresome after a while.
