Stec 30 DG Heading Bug

[wburger1]

I have the Stec 30 with GPSS.  If I want to fly a 180 degree heading I have to set the heading bug to 170 degrees.   Will an overhaul of the DG fix this or is there any adjustment that can be made to the DG or maybe the turn coordinator computer.   All of the modes work correctly except for my 10 degree error on the heading bug. 

[Lance Keve]

Following.  I have same issue but only 3 degrees off.

[Simpson Bennett]

From our tech support team:

"Anytime an AP flies an offset, it is either a faulty input signal (DG) or competing signals (DG / GPSS / VAV) vs. Turn Coordinator.

If the offset was in all modes, I would suspect a TC “roll centering” procedure is needed.

In the situation described, the DG input would be highly suspect.

That said, the DG feeds the ST-901 GPSS converter. Before sending the DG out for overhaul, the DG output to the converter should be checked."

In case you don't have a dealer that you normally use, you can find one here: http://genesys-aerosystems.com/dealer-locator

[carusoam]

Great input, Simpson!

Best regards,

-a-

[wburger1]

Thank you.

[Skyland]

Same problem here.  The heading bug is always left of center to fly a course. It was about 10 degrees off previously but after making the trim pot adjustment on the Stec30 the closest I could get it is about 3 degree left offset.  That was a couple years ago and I’ve been living with it.

When flying in GPSS mode with the 430W it also flys with the same 3 degree course offset.  So both heading mode and GPSS mode have the same offset thus pointing to the autopilot.

I’m on a trip from CA to TX at the moment and on the second leg of the flight that offset problem became suddenly worse. It’s now at least 30 degrees.  IOW, I need to set the bug 30 degrees left of center to fly a course.  When I center the destination (Direct To) on the 430 and engage GPSS the plane veers right, I think trying to fly the offset but I didn’t let it get that far.

Overcast at my destination and didn’t trust the autopilot for either an ILS or RNAV so I hand flew it.  

Troubleshooting suggestions very welcome.

[Bob Weber]

If you know your way around a voltmeter, I can help you troubleshoot this over the phone. I also work with shops that need a little guidance if your not comfortable yourself.

616 822 1999

 

Bob Weber

Autopilot Consulting

WebairConsulting.com

Edited March 4, 2021 by Bob Weber
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