Thanks for the responses
I understood that one of the last fallbacks on the bus if you lost everything was to use the manual pitch trim and the manual rudder to give you some form of control. I assume they consider total loss of power and hydraulics totally inconcievable. However what would of happened to the atlantic glider if the rat had failed to deploy?
I may be over estimating how much use the rudder will be in such a situation. I recall from effects of controls lessons that rudder alone causes a spiral dive, but with trim control I guess you can prevent that and make use of the rudder to point the aircraft in roughly the right direction. (towards land for a ditching off the coast if nothing else)
Any thoughts from Bus Drivers