huh?

Bill
Hey Bill
I speak better with drawing than words but will try it with a few word thingies.
If the control geometry gives equal amount of up and down travel with the bellcrank pushrod attachment arm 90deg to the center line of fuselage, call this the 'normal ' position for lack of better word.
picture all this with the front line being the up line and the bellcrank pushrod arm pointing outboard.
Now lengthen the push rod and picture the bellcrank position NOT the flap or elevator changing position.
The bellcrank output arm is moved to a forward position from normal in the arc it travels in.
This puts things in position so that due to the arc the same degree of bellcrank movement will give less up elevator
and more down.
>>>>>When the bellcrank out put arm is in this forward position at neutral (control surface and handle) then
during up movement the pushrod is moved side ways more than fore and aft compared to the down side movement.
If all linkage ratios in the control system are 1 to 1 then lengthening the push rod to place the the bell crank arm 10deg forward from 'normal' we then will have 10deg less up travel and 10deg more down travel.
This is actually not completely true but easy to picture.
The sensitivity to up and down will also be different.
The push rod length change also requires the handle to be adjusted.
I will read this later when awake and not being chased by work and then probably laugh at myself and make a drawing or 2.

These

are handy for describing arcs and measuring and reproducing exact lengths for playing with the control system geometry.
Back to work I gota go. Why in hell? I do not know!

David