New Trio A/P install PA28 Issues

[Jayp]

I've flown the Trio over 25 hrs now, have a good understanding of its operation. It took a while, maybe just me, but I’m frustrated with the performance. I’ve gotten input from Trio as to gain setting and have experimented with many different setting. no matter the gain settings, in CRS (heading) mode the a/p continually wanders back and forth up to 10 degrees in both directions. Unacceptable.
TRK (GPS course) wanders as well. Unpredictable as to where it goes when engaged. I’ve been left of course, engage and it goes to the left initially then wanders. I’ve engaged TRK mode immediately after entering a direct to waypoint knowing I’m centered on course with same results. Unacceptabl.
Anyone experienced same issues or might offer some direction? Frustrated in Texas

 

[GKC Aviation]

@jakej will be the man

 

[jakej]

I've flown the Trio over 25 hrs now, have a good understanding of its operation. It took a while, maybe just me, but I’m frustrated with the performance. I’ve gotten input from Trio as to gain setting and have experimented with many different setting. no matter the gain settings, in CRS (heading) mode the a/p continually wanders back and forth up to 10 degrees in both directions. Unacceptable.
TRK (GPS course) wanders as well. Unpredictable as to where it goes when engaged. I’ve been left of course, engage and it goes to the left initially then wanders. I’ve engaged TRK mode immediately after entering a direct to waypoint knowing I’m centered on course with same results. Unacceptabl.
Anyone experienced same issues or might offer some direction? Frustrated in Texas

I’m on vacation however I‘ll pm you later today -
just need to know if you’ve done the Servo neutral cal & checked that there is no slop in the aileron linkages?

 

[Jayp]

Thanks Jake, aileron check will be done tomorrow. Appreciate your help, will share our findings

 

[CanucksUnlimited]

Just to add to this - there is a service bulletin:
https://cdn.shopify.com/s/files/1/0..._Pilot_Autopilot_Servo_Mod_1.pdf?v=1745180536
I was having a similar problem, and they replaced the gear named in the bulletin and now it works really well.

 

[Rhino]

There are actually two service bulletins.

Documentation

Trio Autopilot Documentation

www.thestcgroupllc.com

 

[jakej]

Rhino - correct, depending on what equipmentsoftware Jayp has. IF the servos are going back for SB-001 then I’d suggest he has the SB-002 (Gear only) done at the same time - that’s a much more cost effective approach IMO .

 

[CanucksUnlimited]

I had forgotten about the software update - I had that done before the gear SB came out.

 

[Seansull]

Hi Jayp,
I have a PA 28-235 with a relatively new Trio install in Fort Worth (KFWS) . I'm no pro, but I spent a lot of time dialing mine in with input from Jeff at Trio. Happy to attempt to help out if I can. I can at least share my settings etc that are working.
Sean

 

[Jayp]

Thank you Sean, and I sure will contact you. I'm off on vacation next week so it’ll be mid August, but I’ll holler.
i live north of GDJ at XA86.
thank you

 

[Jayp]

Nice panel Sean!

 

[Seansull]

yours too!

 

[Jayp]

Thank you Sean, and I sure will contact you. I'm off on vacation next week so it’ll be mid August, but I’ll holler.
i live north of GDJ at XA86.
thank you

Hi Sean, we were gone a couple of weeks, now back. Flew her last week with some same issues. We did however shoot an LPV at MWL and she did great, GS and all. Will fly again tomorrow and reevaluate a/p perf on both Skyview and Garmin.
do you know your gain settings that got yours settled down? ill Contact you tomorrow with our results.
are you interested in joining us at MWL for lunch sometime, or somewhere else? Jay

 

[Seansull]

Hi Sean, we were gone a couple of weeks, now back. Flew her last week with some same issues. We did however shoot an LPV at MWL and she did great, GS and all. Will fly again tomorrow and reevaluate a/p perf on both Skyview and Garmin.
do you know your gain settings that got yours settled down? ill Contact you tomorrow with our results.
are you interested in joining us at MWL for lunch sometime, or somewhere else? Jay

Hey Jay!
That's great news! I'll copy down my gain settings for you next time I am at the hangar. I'd love to meet for lunch one day. Shoot me a DM and I'll send you my cell and we can coordinate.
Thanks!
Sean

 

[wfcloring]

So, we're having the same issues with our PA28R, both horizontal AND vertical. It is really close, and then just wanders off for a while. and sometimes by more than 1000' vertically! Our plane is really nicely rigged, so when hand flying trimmed out you only need tiny inputs to stay straight and level. We got the brass gear fix, but did not know about any further "engineering changes" in the SB-002 REV A. Also, SB-001 REV A is with regards to Aspen and G5's, and LPV approaches, but we're using a Dynon, and just trying to stay straight and level, so would that even apply? CRS almost works after tons of time tuning, but could never get TRK to hold well regardless of the gains. Do you think the SB-002 REV A full servo changes will fix it? We do get clutch slip messages, but that is because, even though we are initially well trimmed out, the plane starts deviating so much, we have to apply trim to recover!

 

[Jayp]

I feel your pain, Jeff from Trio spent time with us in our PA28-181 and verified good rigging. Reluctant to make any predictions, but pretty sure there is a software update coming soon as he mentioned others with our same issues. Jeff good guy, we’re waiting for the announcement. Too bad the unit needs to be returned to factory for update—

 

[wfcloring]

We have been working with AJ (for over a year now!) The instructions could be a bit clearer, to say the least, but I think we are finally following them correctly. We have pulled the breaker, and tie wrapped it for now. (we're a flying club, so it is OOS until we can get it to work). If we don't get some positive feedback soon, we will likely pull the head altogether and tie a rope to it, as we are always in need of chocks.

The whole thing is really sad, as we have the Dynon AP servos in our BE35s and love them. How they pick a Seneca for AP approval before a PA28 baffles me.