On May 30, 8:25 pm, Mxsmanic wrote:
Bob Crawford writes:
How do you substantiate your initial claim that "[Real life GA]
autopilots make coordinated turns even when they cannot control the
rudder"?

By watching the ball in the turn indicator. It moves far less in an AP turn
without rudder than it moves when I make a turn without rudder.

But you're watching the ball in a simulator. What's that
got to do with ANY claim about a real life GA plane?
Watch the ball in a real life plane, (or pay attention to
someone who has actually watched the ball in a
real life plane) and you'll see that autopilots that
can't control the rudder turn in the same way that
a hand-flying pilot turns when he keeps his foot
away from the rudder pedals. Generally speaking,
both will be slightly uncoordinated.

The degree of uncoordination varies from one
plane to the next, but at least in cruise, it's
normally not enough to matter too much. In
those planes where the AP can't control the
rudder, the decision was made that the
lack of coordination is not severe enough
to justify the extra expense and weight
penalty of giving the AP control over the
rudder.

Everyone's telling you the same thing -- real life
planes don't behave the way you're describing the
simulator to behave. Furthermore, the fact that
you've asked the question that started this thread
indicates you find some cognative dissonance
in the simulator's behavior on this point. It
simply doesn't make sense that an autopilot
with no rudder control could maintain coordination
in a situation where a human would require
rudder control to maintain coordination.

You have two choices: Either the simulator's
right, all the real pilots and real planes are
wrong, and there is some unexplainable
magic that allows the autopilot to maintain
coordination in a situation where rudder input
is required but not available, or else there's
no magic, real planes behave the way
real planes are observed to behave, and
the simulator is wrong on this particular
point.

It's obvious that you've made your choice
as to which alternative you want to
believe.