"Jose" wrote in message news:1MzNg.443
This makes no sense to me. If the airplane attitude remains "where
desired" (I presume that is the same as where you put it, using pressure)
when you release the pressure, then the pressure isn't doing anything.
How do you fly such an aircraft?

The way I look at it is that you have to use a different combination of
sensory data than if you were flying a small aircraft with direct cable
controls and elevator trim.
In the 727, my recollection is that there is not a complete lack of feedback
feeling; there is a little, but it is different from flying traditional trim
tabs.

On the 727 (and, I presume, on the 707) you have a movable stabilizer, an
elevator, and elevator trim tabs. The elevator trim tabs are locked out of
the trim system as long as the electric stab trim motors are functional.
When locked out, they function as balance tabs. There is an elevator feel
computer in the 727 whose main purpose is not to provide yoke force
feedback, but it does give some little feeling to the yoke as a side effect.

The bottom line, at least in my perception, is that with some experience in
the aircraft you can become very adept at simultaneously positioning your
attitude, and adjusting the trim so you don't have to keep positioning your
attitude. Of course, as the craft accelerates or decelerates you have to
repeat the process as configuration and speed change. As a practical
matter, you are [almost] flying with the stab trim.