left-right play in SGS 1-26 stick?

My bet is that the single greatest contributor is the pitch pivot at
the base of the control stick. I think you will find that the holes
for the pivot bolt are elongated, and allow the stick to move a great
deal before engaging the torque tube that runs under the pilot seat.

Thanks, Bob K.

I agree with Bob. I believe there is a service bulletin (Not an AD)
to fix this. See the K&L site.

aerodyne

On Tuesday, July 17, 2012 10:25:27 AM UTC-4, aerodyne wrote:
>
> My bet is that the single greatest contributor is the pitch pivot at
> the base of the control stick. I think you will find that the holes
> for the pivot bolt are elongated, and allow the stick to move a great
> deal before engaging the torque tube that runs under the pilot seat.
>
> Thanks, Bob K.

I agree with Bob. I believe there is a service bulletin (Not an AD)
to fix this. See the K&L site.


This is a C, the service bulletin is for 1-26 D and E. It concerns the wrong bolt being installed in some ships.

It does state that the expected side-to-side movement is 1/8" not the 1/2" that I observe.

The wierd thing is that the play is only right-left, the elevator control linkage has no play. If the cause is an elongation of a hole, I wonder why the wear is in only one axis.

On Jul 17, 11:23*am, son_of_flubber wrote:

...The wierd thing is that the play is only right-left, the elevator
control linkage has no play. *If the cause is an elongation of a
hole, I wonder why the wear is in only one axis.

If you look at how the mechanism works, you'll see that it is not
weird at all. The torque tube decouples pitch and roll inputs so their
levels of free play can be completely different. Pitch inputs move a
short push-pull tube which actuates a walking beam connected to the
two elevator cables. Roll inputs rotate the torque tube under the
seat, which moves a vertical push-pull tube behind the spar; that push-
pull tube actuates a bellcrank that connects to the aileron push-pull
tubes in each wing.

Thanks, Bob K.

The service bulletin instructs to contact the factory if play exceeds
1/8".

IIRC, there is a standard repair involving bushings. Call K&L for
disposition.

aerodyne