Skip to main content

Elevator Trim Tab Play / Slop

There is some play / slop in my elevator trim tabs. I am not sure if it is excessive or not. The source of the slop is at the bolt that attaches the actuator to the control rod. If I am reading the IPC correctly, this is where part number "46", 45-524563 attaches to part number "73" 45-135037.

Here is a short video, shot from below. https://youtube.com/shorts/0UcfIdrMbl0

Model: Debonair 35-B33
Aircraft Serial Number: CD-636
Posted 11/7/2023 - 3 months ago
|

Replies Sort

Good evening, Jim.

I'm not going to try to upsell you, but a few things to understand. That is a close tolerance bolt - or at least it should be. Note how it is rocking off-parallel. This would indicate the fork, as well as the actuator end, are also worn. As I'm sure you noticed, there is quite a bit of play on the trailing edge of the tab to the elevator itself. You might want to research your logs for an actuator overhaul. This would include the bearings, screw itself, and the aft bushing. The bushing rides on the aft screw shank (look for vertical play in the rod end: That particular fit of new parts is 0.0005"), which is what the actuator end (rod end) is attached to. All of this play accumulates. Look at the other side also. Once you find time in service (2000-hours is a good number) and what other play you have, you will likely upsell yourself.

Mike
ABS Technical Advisor

Posted 11/7/2023 - 3 months ago
|
Approved by Bob Ripley
Quote

Thanks, Mike. I will check for play on the actuator rod and see if I need to start collecting parts for that project.

No argument that I think the two parts joined by that bolt need replacement. I found one of those on the txtav parts site and have inquiries to them on others for the other part.

If I am reading the IPC correctly, that would be part number "46" (45-524563) and part number "73" (45-135037).

If I am remembering correctly...I attended an ABS clinic in Indy a few years back. Bob noted play at the trim tab to control rod joint. Those are the nuts/bolts we check in preflight to make sure they rotate / aren't siezed. I wrote down the PNs for bolts that Bob mentioned and we (A&P and I) later replaced. I'm guessing that PN was the close tolerance bolts you speak of (AN173C5) and what I had in there were incorrect and installed after my paint job. I suppose I should have done those at the same time.

Quote

Your reference number call-outs are correct. Joining bolt is #71.

Mike
ABS Technical Advisor

Posted 11/11/2023 - 3 months ago
|
Quote

Elevator Trim Tab Play / Slop