Pitch Trim Actuators

[Gatorman]

Hey guys, just got a service bulletin on pitch trim actuators to add some clips to the lower gimbal pins and ran across a problem....

In the special check of the bulletin, it calls out to check the gap under the gimbal pin head and the aircraft I am working on has gone beyond the limits.


Has any one else experience this?

 

[avbug]

Actuators out of limits? Sure. Are you talking about a clearance gap, or are you checking end play with a dial indicator?

Regardless, if it's out of limits, it's out of limits. Replace or repair it. In most caes, you're unable to repair it, and it's far less expensive and easier to replace the entire unit. Not to mention that the liability for the condition of the unit falls back to the person who overhauled it, instead of you.

 

[Gatorman]

The end play you were referring to, I believe, is done on the scheduled maintenance check. I was talking about the Goodrich service bulletin that just came out recently to measure the fwd and aft lower pins at the bottom of the screw jack. The max allowed gap is 0.230 and we came up with 0.235.
We have gathered the info and sent it off to the aircraft mfr and they are sending to the product mfr for the next step. I think that they are going to let it slid. The forward pin was well within limits.


Just wondering if anyone else has done this bulletin. I am always skeptical about service bulltins or anything like that when the first one that I find is bad. Makes me wonder if I am doing something wrong, so far I havn't been wrong....it is just a funny feeling.

 

[Gatorman]

End result....pull lower gimbal pin, dye penatrant inspection, and reinstall if no defects found. Replace if needed.

Bummer, I was looking for something cool to do to it.

Well, I guess that closes this thread.