757 avionics

FriarTuck wrote in
:

some questions if anyone knows the answers...

is 757 fly by wire or fly by cable?


Neither


The FMCS has full flight and landing capability, is it a separate
control system?

It can autland but it's seperate from the flight controls. You can
disengage it anytime you like.
It fails passive, which means you can manually oer-ride any time you
want.


The FANS network, is it capable of directing "goto location/altitude"
and "set airspeed to K" type commands to the plane?


Doesn't have one


Is the yoke and throttle a completely separate control system from the
FMCS control system or are they common?


seperate

is the throttle control in cockpit only routed through FMCS ?

No


I read that the yoke was capable of exerting more power on the
surfaces than the FMCS could, essentially giving yoke priority, is
that correct? If so can you describe how that works?


The stick will give more authority because the autopiot flies the
airplane in a more limited way than a pilot would. When it intercepts an
altitude, it does so smoothly with a limited G. A pilot can manuever the
airplane as abruptly as he likes, but of course, most do so just as
smoothly as the autopilot does.
Sometimes the autopilot isn't quite so smooth. If it gets "surprised" by
a track interception, for instance, it will be a bit jerky in roll, or
if it gets surprised by a pitch intercept it wasn't expecting and the
autothrottle gets a bit out of step it will pitch a bit harshly. Ridig
as a passenger this sort of thing is often felt in the back and mistaken
for hand flying.


Bertie