Sticking yoke

soxinbox wrote:
When doing steep turns, I noticed that there is a little resistance to pitch
changes on the yoke. It seems it binds a little in the bearing through the
panel. Does anyone have a suggestion for the type of lubricant I could use
on this? Do they make anything for this purpose?


What sort of airplane is it? Some of the older 172s had a
problem with a bending/breaking panel brace that would let the panel
flex enough that the control shaft bearing would start snagging and
restricting elevator control.
172s also have a problem with cracking forward horizontal stab
spars (caused mostly by people pushing down on the stab to turn the
airplane on the ground when parking or whatever) and I have seen the
spar broken clear through so that only the skin was keeping things
straight. Under higher loadings (such as a steep turn) the stab will
flex downward, misaligning the elevator hinges and making the elevator
stiffer. A really bad sign. Might be a good idea to get it checked, if
it's a 172. Look around the big lightening hole in the stab's forward
spar.
Sticky controls also result when pulley bearings dry out and
the pulley stops (or resists) turning.

Dan

My plane is a turbo arrow IV. The sticking is definitely right in the
bearing that goes through the panel. It provides just a little bit of
resistance so that when you try to make fine adjustments, its sticks and
then gives a little causing me to slightly overshoot. It does not pose a
real problem, but I think I would be more precise if it was smooth as silk.
I am now working on my instrument rating and that is all about being smooth.


wrote in message
ps.com...

soxinbox wrote:
When doing steep turns, I noticed that there is a little resistance to
pitch
changes on the yoke. It seems it binds a little in the bearing through
the
panel. Does anyone have a suggestion for the type of lubricant I could
use
on this? Do they make anything for this purpose?


What sort of airplane is it? Some of the older 172s had a
problem with a bending/breaking panel brace that would let the panel
flex enough that the control shaft bearing would start snagging and
restricting elevator control.
172s also have a problem with cracking forward horizontal stab
spars (caused mostly by people pushing down on the stab to turn the
airplane on the ground when parking or whatever) and I have seen the
spar broken clear through so that only the skin was keeping things
straight. Under higher loadings (such as a steep turn) the stab will
flex downward, misaligning the elevator hinges and making the elevator
stiffer. A really bad sign. Might be a good idea to get it checked, if
it's a 172. Look around the big lightening hole in the stab's forward
spar.
Sticky controls also result when pulley bearings dry out and
the pulley stops (or resists) turning.

Dan

soxinbox wrote:
My plane is a turbo arrow IV. The sticking is definitely right in the
bearing that goes through the panel. It provides just a little bit of
resistance so that when you try to make fine adjustments, its sticks and
then gives a little causing me to slightly overshoot. It does not pose a
real problem, but I think I would be more precise if it was smooth as silk.
I am now working on my instrument rating and that is all about being smooth.

That sticking / overshooting phenomenon is endemic to the whole Cherokee model
line if that bearing is not kept lubricated. I used a silicone lubricant when I
owned one. It makes a huge difference in the flying qualities of the airplane.
Reapply the silicone every oil change.

I have a Cessna 150 that had silicone sprayed on the yoke shaft during it's
annual without me knowing. The next time I fly it the yoke was grabby. I
wiped off most of the silicone and use a little Wd40. Was ok after that.
Roger

"Dave Butler" wrote in message
news:1140709739.67207@sj-nntpcache-5...
soxinbox wrote:
My plane is a turbo arrow IV. The sticking is definitely right in the
bearing that goes through the panel. It provides just a little bit of
resistance so that when you try to make fine adjustments, its sticks and
then gives a little causing me to slightly overshoot. It does not pose a
real problem, but I think I would be more precise if it was smooth as
silk. I am now working on my instrument rating and that is all about
being smooth.

That sticking / overshooting phenomenon is endemic to the whole Cherokee
model line if that bearing is not kept lubricated. I used a silicone
lubricant when I owned one. It makes a huge difference in the flying
qualities of the airplane. Reapply the silicone every oil change.

In my Seneca the bushing sort of floats and articulates as the shaft
changes angles as it is pulled aft. On the left side it doesn't and I
think it is a bit of a binding problem for me. Very minor and keeping it
lubed seems to fix it.

soxinbox wrote:

When doing steep turns, I noticed that there is a little resistance to pitch
changes on the yoke. It seems it binds a little in the bearing through the
panel. Does anyone have a suggestion for the type of lubricant I could use
on this? Do they make anything for this purpose?