What is interesting is that several people have described exactly what the Airbus FBW system does, then others come on and say that's rubbish and go on to describe what they think it does.....and their description amounts to the same but with different words!
All that is being argued here is terminology: I say that even with AP out "it's like the AP is still in...but the Navigation commands are coming from different places". Others say no that's rubbish with the AP out the ELAC is still helping, but people:
the principle is the same.
For example:
Quote:
On AB with the AP off, actually the AP is still on, in mode called attitude hold or control stick steering in other aircraft. Where ever the aircraft is pointed in pitch and roll, the aircraft tries to maintain those positions.
Sorry marine, but that is rubbish. Are you type rated in the 320??
...is not really rubbish is it? Read it again carefully, Micro, I think it describes what the FBW does very well.
Silton, This is what myself and others are trying to get across. The Airbus FBW system is different to conventional mechanical flight controls. It flies differently -
like the autopilot is always in. Yes; a Tornado, for example, has a very responsive FBW system, because it is a fighter jet and may need to execute escape or kill manoeuvers at high 'G'. A passenger jet does not want a fighter like response, it is "sluggish" partly for passenger comfort, and partly never to exceed it's design limit of 2.5G. With mechanical controls, one could overstress the aircraft by commanding full deflection. With the Airbus the FBW will not allow the airframe to be overstressed*, and it will try to maintain whatever attitude you last commanded. This needs a different technique when handflying the FBW Airbus. BUT it's something that no trainer has ever taught (me), I've only ever been told "hold the sidestick only on the top/only on the bottom/don't touch it etc etc, which are completely unhelpful. I've seen senior Captains overcontrolling and getting into PIO's because they too do not understand how the FBW works, and have never had it explained to them. Understanding what the FBW is doing helps one to handfly the aircraft much better.
*PS: Before I get shot down again; most Airbus rudders are mechanically linked to the rudder pedals. Therefore it
is possible to overstress the rudder.