Recent content by airguy

I would suspect you have a bug or some kind of blockage in the second line sensing AOA, not the main pitot tube line. It would give exactly the symptoms you describe.

Tell me about it. I'm still waiting for the promised auto-trim functionality on the 172R/S models for their STC'd autopilot install - 5 years after installation. The "after-the-sale" support is somewhat lacking.

Yep, go back to standard TOD mental gymnastics. In my RV9A for instance I usually come down at 1000fpm, covering about 3 miles per minute, if I need to drop 9000' it will take 27 miles.

For troubleshooting or fault-finding, I agree that more is always better - but reality is that we cannot instrument everything to the maximum degree possible in our aircraft. From an operations standpoint, I don't care if one or two (or three) of the autopilot servos have a problem in flight -...

You're going to enjoy this STC. One issue you should be prepared for is some fishtailing on the AP holding heading, there is a procedure available from Dynon for in-flight autopilot tuning and once we went through that a few times we had it pretty much knocked down.

Yup, welcome to the frustrating world of intermittent electrical faults. Hardest thing to diagnose/find.

Those two pieces of data point to a loose cable connection, as things warm up some pins stop making contact.

You have separate grounds for each servo, so that's not likely the problem - but both servos are fed from a common power supply, and both servos are going offline/online together - that's your smoking gun. You most likely have a power supply problem to them.

Were either of the screens (new or old) sold as a certified unit versus experimental?

If you don't find an obvious short to ground somewhere, the possibility exists that it is a legitimate alarm from the battery. Attached here is the fault-list for ETX

That indicator is "grounded" to indicate a fault - so if you have a point where the insulation is rubbed through and it is shorting to ground, it will look like an intermittent fault on the panel.

Does the airplane have an EarthX battery in it? That battery has an internal fault indicator with an external wire that can go to the EMS to indicate a problem. That wire normally "floats" as an open wire, but when there is a battery fault the internal battery circuitry ties it to ground - also...

Was that a Dynon-produced cable or owner-built?

There's a reason they make covers for pitot tubes...