Found my rudder trim issue (Piper Lance)

cowman

cowman

Final Approach
PoA Supporter
Joined
Aug 12, 2012
Messages
5,461
Location
Danger Zone
Display Name
Display name:
Cowman
Plane just finished annual, one of my squawks was I kept having to go full left on the rudder trim to center the ball. Flew over to another shop to put in a new pitch servo for the autopilot and they found this…..

This is the turnbuckle for the rudder trim.

A29D0F8A-E415-48DA-AB48-5A3F0476DE3C.jpeg

*Edit guess I was wrong, PA32 owners group on FB clued us in. That’s stabilator trim, there is no rudder trim cable in the tail.
 
Last edited:
Yikes, saved by the safety wire. Textron has put out an AD on some Beechcraft's (mine was in it) to do an inspection on the turnbuckles that connect to the aileron. Reports had found some turnbuckles corroded and broke in that exact spot! I'd check others, glad they found it!
 
Correction: we still don’t know what’s up with the rudder trim. That’s actually stabilator trim.
 
Yikes. I wouldn't be back at that shop. What else are they not looking at?

Fwiw, I believe that's actually your elevator trim, which is even scarier. The rudder trim is a screw that works against the bar the pedals are on.

I had the same issue with the rudder trim. Once we got the plane to fly wings level, he adjusted the rudder a bit to get the trim more centered.
 
Jim K said:
Yikes. I wouldn't be back at that shop. What else are they not looking at?

Fwiw, I believe that's actually your elevator trim, which is even scarier. The rudder trim is a screw that works against the bar the pedals are on.

I had the same issue with the rudder trim. Once we got the plane to fly wings level, he adjusted the rudder a bit to get the trim more centered.
Click to expand...

It is in fact stabilator trim. I’m not at my usual mechanic, I am at a different shop I go to for avionics and they found it while replacing a pitch servo.
 
cowman said:
It is in fact stabilator trim. I’m not at my usual mechanic, I am at a different shop I go to for avionics and they found it while replacing a pitch servo.
Click to expand...
I saw your update after I posted. There's an AD to inspect those turnbuckles annually. Whoever signed off the annual either pencil whipped it or is incompetent.
 
Jim K said:
I saw your update after I posted. There's an AD to inspect those turnbuckles annually. Whoever signed off the annual either pencil whipped it or is incompetent.
Click to expand...

The trim cable or the stabilator control cables? There’s a log entry for AD2013-02-13 that SB1245A was done and the ad is complied with until 2027. But that’s for the main stab cables not the trim I think.

It broke on the cable end, rust and pitting apparent.
 

Attachments

  • FC6EF0DA-8901-47D6-8AC2-50FFA96AED38.jpeg
    FC6EF0DA-8901-47D6-8AC2-50FFA96AED38.jpeg
    193.9 KB · Views: 43
cowman said:
The trim cable or the stabilator control cables? There’s a log entry for AD2013-02-13 that SB1245A was done and the ad is complied with until 2027. But that’s for the main stab cables not the trim I think.

It broke on the cable end, rust and pitting apparent.
Click to expand...

You're right, the AD & SAIB refer specifically to the flight control, not the trim. But if you're back there, It'd be criminal to not look at the others.
 
Yeah I’d be pretty leery of whatever mechanic you’ve been using for your past annuals. They should’ve caught that, but I’m very glad it was discovered now!
 
Jim K said:
Yikes. I wouldn't be back at that shop. What else are they not looking at?
Click to expand...
Yup. Pulling enough interior out to get into the tailcone and under the floor to see stuff takes time and work and costs money, so it's often just pencil-whipped. I guess the regs requiring inspection of all systems for correct assembly, condition and operation just don't mean much to some mechanics. What if the stabilator cables themselves were failing?? With a trim system ready to fail, too? No pitch control whatever. As the fleet ages I expect to see more accidents due to shoddy maintenance.

https://www.ecfr.gov/current/title-14/chapter-I/subchapter-C/part-43/appendix-Appendix D to Part 43
 
Dan Thomas said:
Yup. Pulling enough interior out to get into the tailcone and under the floor to see stuff takes time and work and costs money, so it's often just pencil-whipped. I guess the regs requiring inspection of all systems for correct assembly, condition and operation just don't mean much to some mechanics. What if the stabilator cables themselves were failing?? With a trim system ready to fail, too? No pitch control whatever. As the fleet ages I expect to see more accidents due to shoddy maintenance.

https://www.ecfr.gov/current/title-14/chapter-I/subchapter-C/part-43/appendix-Appendix D to Part 43
Click to expand...
It's worse than that... all those turnbuckles are next to each other back in the tailcone, and easy to access. There's a panel back there big enough -I- could fit through it, secured by two 1/4 turn fasteners.

Having someone else inspect all of them is a good call.

My mechanic replaced my stab trim cable at annual because he, you know, actually inspected it, and found some play in the turnbuckle. $1100 parts & labor.
 
Cowman, did you ever end up determining the actual cause of your issue? I have a Saratoga with the exact same problem.
 
Last edited:
Pic is finding during a recent AD 2013-02-23 inspection.My belief is they were mfg that way after talking with Macfarlane folks. I can’t prove it’s bad
but absolutely can’t prove it’s good. We replaced all stab cables. Early Cherokee.

The problem has been apparent for many years and pilots are still not aware of emergency action.You have very little time to learn to fly after a failure.

IMHO Assuming a UP stab failure:

1. Lots of UP trim

2. Vary DOWN pressure on yoke till able to land.


Better way?
 

Attachments

  • IMG_2137.png
    IMG_2137.png
    3.6 MB · Views: 24
You must log in or register to reply here.
Back
Top