Just about every time I touch the throttle or tweak my altitude.
--
Gene Seibel
Gene & Sue's Aeroplanes - http://pad39a.com/gene/planes.html
Because we fly, we envy no one.


Mxsmanic wrote:
What I see in the literature seems to vary between warnings against
spending too much trim or flying with trim tabs, and not ever trimming
the aircraft at all. So how much and when should I trim?

I understand trim to be a convenience, so that a pilot doesn't have to
constantly maintain force against the controls for long periods. Thus
it should never be dangerous not to trim, except insofar as it can be
tiring to hold an untrimmed aircraft in a given attitude for long
periods.

The thing I wonder about is the possible distraction of trimming the
aircraft. It looks like trim controls are often in spots like the
pedestal or throttle quadrant, where presumably one must direct one's
attention in order to adjust trim. It's hard to imagine doing this
during critical phases of flight such as take-off or landing, and yet
I read recommendations for trim in both cases. Where do you draw the
line between trimming unnecessarily and not trimming enough? How
often do you actually reach for the trim controls?

Also, it seems that most trim is pitch trim. I don't see much mention
of aileron or rudder trim. Do you use it? Do you ever trim out
P-factor or torque effects? I turned both back on in my sim and
adjusted them to where the vendor says they should be to match the
real aircraft, and I find them irritating, but not overwhelming (the
vendor has apparently set the most realistic factors at 50% instead of
100%, so that masochists can increase their effects beyond real life
if desired).

Another problem I have: How do you remember where you set the trim?
I know you can look, and I know that you can guess if the aircraft is
behaving strangely, but how do you keep track of where you last set
the trim? Each time I set it I tend to forget about it until some
important moment when I'm already busy with other things.

Also, I presume that most autopilots use trim for pitch control. If
you shut off the autopilot, does the trim remain whereever the A/P set
it? If so, do you change it? Is it hard to remember that the A/P has
probably changed it?

--
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