TruTrak ADI Pilot II autopilot...problem or not?

[Tom @ N269CP]

Hey guys, I have what may be a simple question regarding basic operation of the subject autopilot. I've contact TruTrak who cannot provide any insights.

My plane just came out of annual. While taxiing to the runway for my first post-annual flight my autopilot somehow became engaged....its possible I bumped the right button while setting the altimeter, but I'd never done that before. And because of sunlight on the panel I could not see any of the indicator lights. So I taxiied back to my hangar to troubleshoot. Once there, I saw that the autopilot was in Trak mode. So I simply pressed the right button a couple of times to cycle it to off. But it would not cycle next through Nav mode to off, as has been how I normally turned it off when airborne.

My autopilot disengage button on my grip shuts it off, as does holding the right button for 1-2 secs.

My question is this: Can the autopilot be set in Nav mode while on the ground? Or is it interlocked to prevent this?

The TruTrak manual is silent on this.

I've had instrument issues during and after my last two annuals...had to replace my previously working elevator trim servo and indicator after this latest annual. So am a bit frustrated by this as well as TruTrak's inability to provide any insights into the above simple question.

[Ted RV8]

Isn?t there a minimum speed setting in the set up for the autopilot?

[Tom @ N269CP]

Originally Posted by Ted RV8

Isn?t there a minimum speed setting in the set up for the autopilot?

There is a setting for this, I honestly don't know what it is. Not sure it applies here. But while stationary it does go into Alt Hold mode and Trak mode and takes control of the stick...it just doesn't go into Nav mode.

This morning I've experimented with seeing if keying the mike turned the a/p on...as reported elsewhere here, but that does not appear to be the case.

[chrispratt]

FWIW If you have an Infinity stick grip or similar you can inadvertently depress the autopilot button on the stick and it will engage the Track mode. I did this once while practicing touch and go's. During a hard landing, my thumb must have depressed the button momentarily but long enough to engage Tracking mode. This can be a real shocker as you are climbing out and feel a "frozen" stick as you start your turn at low altitude.

According to the TruTrak installation manual, only the tracking mode is engaged. I can verify that.

When shutting off my ADI Pilot II, I always simply blip the disengage button on the Infinity grip. I don't cycle through Tracking, Nav, etc. by repeatedly pressing the control button (on right).

The important thing to be aware of is that the "AP disengage" button on the grip is really an "engage" button as well. Only takes about 1.5 seconds to engage. So part of my pre-takeoff checklist is to check that Autopilot is off.

Chris

[Ted RV8]

Originally Posted by Tom @ N269CP

There is a setting for this, I honestly don't know what it is. Not sure it applies here. But while stationary it does go into Alt Hold mode and Trak mode and takes control of the stick...it just doesn't go into Nav mode.

This morning I've experimented with seeing if keying the mike turned the a/p on...as reported elsewhere here, but that does not appear to be the case.

Believe it sets a minimum speed that will allow the autopilot to engage. Maybe not applicable to your issue. Surprised Trutrak didn?t cover that when you called them.
My Trutrak is a different model but it has that in the set up mode.

[Tom @ N269CP]

Originally Posted by chrispratt

FWIW If you have an Infinity stick grip or similar you can inadvertently depress the autopilot button on the stick and it will engage the Track mode. I did this once while practicing touch and go's. During a hard landing, my thumb must have depressed the button momentarily but long enough to engage Tracking mode. This can be a real shocker as you are climbing out and feel a "frozen" stick as you start your turn at low altitude.

According to the TruTrak installation manual, only the tracking mode is engaged. I can verify that.

When shutting off my ADI Pilot II, I always simply blip the disengage button on the Infinity grip. I don't cycle through Tracking, Nav, etc. by repeatedly pressing the control button (on right).

The important thing to be aware of is that the "AP disengage" button on the grip is really an "engage" button as well. Only takes about 1.5 seconds to engage. So part of my pre-takeoff checklist is to check that Autopilot is off.

Chris

Very interesting, Chris. I didn't know that about the a/p disengage button also engaging the a/p....I can now confirm that is true for mine as well. It's the only a/p button on my grip. Yes, looks like a good checklist item.

I'll bet you were surprised to find the a/p on during climb out.

[Tom @ N269CP]

Originally Posted by Ted RV8

Believe it sets a minimum speed that will allow the autopilot to engage. Maybe not applicable to your issue. Surprised Trutrak didn?t cover that when you called them.
My Trutrak is a different model but it has that in the set up mode.

TruTrak simply referred me to the manual and said they could not answer my question. No attempt to troubleshoot it by them. You'd think they'd have somebody around there, or who they could call, who supported these a/p's. Apparently not.

I was not impressed, nor am I keen on their new "upgraded" version with the single "magic do-everyting" joystick input. This is one of my main concerns with proprietary black box electronics....their typical early obsolescence. It's why I went for steam gauges. The TruTrak ADI Pilot I & II a/p is nice and simple. Don't fix it if it ain't broke.

[BobTurner]

Originally Posted by Tom @ N269CP

Very interesting, Chris. I didn't know that about the a/p disengage button also engaging the a/p....I can now confirm that is true for mine as well.
ut.

Pushing and holding, for a few seconds, the disengage button, should, on release, bring the autopilot on-line in a specific mode. I think they call it PCS, pilot command steering. The autopilot should attempt to hold the heading you are in when you release the button. If level, it should keep you level. If in a climb, it should keep you climbing, etc.
My opinion: autopilots and electric trim systems should have an obvious, one-action means of disabling them, quickly.
My opinion: I have a Trio autopilot, which, because it uses a slip clutch instead of shear screws, doesn?t suffer from the ?locked stick? problem.

[chrispratt]

Originally Posted by Tom @ N269CP

Very interesting, Chris. I didn't know that about the a/p disengage button also engaging the a/p....I can now confirm that is true for mine as well. It's the only a/p button on my grip. Yes, looks like a good checklist item.

I'll bet you were surprised to find the a/p on during climb out.

Let's say "a little more than surprised". Trying to figure out what was going on at 300 ft altitude is a real lesson in flight discipline and very revealing about what your mental check-list tells you is happening vs. reality. At least I figured out that the elevator still worked ok and the rudder worked ok. So I can fly with that and return to base to figure out what's going on with the ailerons.

BTW, the TruTrack installation guide does mention this, but it is buried in one of those long old-style typewriter paragraph's that you forget about as soon as you read it.

Fly safe!

Chris

[Tom @ N269CP]

Originally Posted by BobTurner

Pushing and holding, for a few seconds, the disengage button, should, on release, bring the autopilot on-line in a specific mode. I think they call it PCS, pilot command steering. The autopilot should attempt to hold the heading you are in when you release the button. If level, it should keep you level. If in a climb, it should keep you climbing, etc.
My opinion: autopilots and electric trim systems should have an obvious, one-action means of disabling them, quickly.
My opinion: I have a Trio autopilot, which, because it uses a slip clutch instead of shear screws, doesn?t suffer from the ?locked stick? problem.

My TruTrak must use some kind of slip clutch as it didn't require much stick force to override it...which I'm glad to have discovered while still on the ground.

My initial thought was that it was some notchy sticktion somewhere in the aileron control linkages...as mentioned, it had just came out of annual. It didn't dawn on me that the a/p had engaged till I got back to the hangar.