Autopilot disconnect button

[AlanR]

Hi,
After 4years working just fine my Autopilot remote disconnect button has stopped working. The A/P works and disconnects just fine from the twin D1000's in the panel but not when I press the remote button.
When the button is pressed with the autopilot engaged I get a 'Pitch Slip' indication. If I press again the disconnect button I get 'Roll Slip' indication. If I then hold the button for a couple of seconds I get both a 'Pitch Slip' and 'Roll Slip' indication which then changes to 'Slip Trim Nose Down' indication but the autopilot does not disconnect.
Anyone had similar to this and thoughts on if this a Config problem in the D1000's or a Button Switch/Resistor problem?
My initial thoughts are that actual button must be ok or I wouldn't be getting any indications at all.

Thanks,

Alan.

 

[airguy]

Reference section 3 of the installation manual, specifically pages 3-9 for how to enter Setup Mode, and 3-16 for the Autopilot Setup menu. This will give you some diagnostic data about what is happening with the servos and the disconnect button.

 

[RV9APlane]

Interestingly, I’ve had a similar issue recently. The AP disconnect button started not working intermittently and then all of a sudden my pitch servo stopped working or works erratically. I flew from Minneapolis to Bakersfield, CA yesterday with no reliable pitch control. 11.3 hours of grueling flight. I just started looking on here for ideas and saw this post, wondering if the AP disconnect button issue and my pitch servo issue are related.

 

[kellym]

Interestingly, I’ve had a similar issue recently. The AP disconnect button started not working intermittently and then all of a sudden my pitch servo stopped working or works erratically. I flew from Minneapolis to Bakersfield, CA yesterday with no reliable pitch control. 11.3 hours of grueling flight. I just started looking on here for ideas and saw this post, wondering if the AP disconnect button issue and my pitch servo issue are related.

Sounds a lot like you have a sheared pin on your pitch servo, regardless of whether you disconnect has a problem.

 

[RV9APlane]

So I’ve been looking to purchase the servo shear screw kit, part #102991-000, and has available documentation but I don’t see any way to purchase it online. it doesn’t show up anywhere on the product search either. How do I get one?

 

[kellym]

So I’ve been looking to purchase the servo shear screw kit, part #102991-000, and has available documentation but I don’t see any way to purchase it online. it doesn’t show up anywhere on the product search either. How do I get one?

call support. IIRC they may not charge for it.

 

[AlanR]

Well...My problem as the original poster is definitely not the Shear screw as the Autopilot works just perfectly ok when controlled from the twin D1000's.
It is the Autopilot disconnect that is not working as it should.

It does not disconnect when the remote button is pressed but shows Pitch and roll indications.
I do not have at any time messages of 'Disconnect switch broken' or anything like that when the A/P is in operation.
After airguys's suggestion I have had a look in Config whilst in the hangar and all appears normal as regards settings and config. It shows disconnect button configured as it should but shows button not pressed. Pressing the button when not in A/P does not do anything but then I don't suppose it would anyway.
However, If I then put the A/P in 'Level', trying to simulate operating the A/P in flight, and press the disconnect button it still shows 'Button not pressed' but whilst still holding the disconnect button down it does stop the autopilot trying to level the aircraft and again shows the Roll and Pitch indications as before. (I did this in Config on P1 screen whilst viewing P2 screen) so could see that it showed 'Button not pressed' although pressing the button was clearly creating the indications on the Skyview.
So my conclusion so far is that the momentary disconnect button is working ok but somehow the Skyview is not responding and switching the Autopilot off from the remote button?....hmmm.
See pics showing config and shots of when the disconnect button is pressed showing Pitch/Roll indications.
I have emailed Dynon for their thoughts but whilst waiting for a reply any further thoughts on here would be appreciated particularly if someone has had the same or similar issue.

Thanks,

Alan.

 

[kellym]

Two options. You can bypass the disconnect button by placing another in parallel, and see if you get different results with the temporary button...if so, the installed button is not making a good connection. Or you could check resistance across your button with it not pressed and with it pressed.
While you are getting some response when you press, the fact that the status screen shows it not pressed is pretty strong evidence that it is not making a good connection.

 

[AlanR]

Two options. You can bypass the disconnect button by placing another in parallel, and see if you get different results with the temporary button...if so, the installed button is not making a good connection. Or you could check resistance across your button with it not pressed and with it pressed.
While you are getting some response when you press, the fact that the status screen shows it not pressed is pretty strong evidence that it is not making a good connection.

Thats a good idea..Thanks for that. The switch is mounted in the centre console and will be awkward to get to but I am sure I can rig something up temporarily without ripping everything apart just yet until I have a proper diagnosis.

However, just thinking.. If it is wire break or connection problem somewhere I would have thought though that I should be getting both audio and visual message 'Autopilot Disconnect Broken' which is the purpose of having the message system in Skyview if the disconnect is not working. Why am I not getting this message I wonder?
Having had both screens back to Dynon within the last 18months for 'Screen of death' problems my big fear of course is something electronic with Skyview not triggering the response...

Thanks again.

Alan.

 

[RV9APlane]

Sorry I hijacked your thread Alan, although I’ve had a similar problem which is what brought me to it in the first place. I removed my pitch servo today and the shear screw is sheared, will be calling Dynon in the morning. I’ll still have to figure out the disconnect issue. Thanks everyone!

 

[AlanR]

Now in discussion with Don at Dynon about this but just to update this thread:-

Further to this..
I flew today 2 x 2.5hour flights today and the Disconnect button worked perfectly!....I must have pressed it a dozen or more times on each flight just trying to provoke it or make it not work and it worked just perfectly, disconnecting the A/P every time.
I was thinking along the lines of changing out the switch and the resistor but how it has worked perfectly ok today says to me that there is nothing wrong with the existing switch or resistor so I am not going to do that now.
I am now wondering if some sort of software glitch in my D1000 Skyview screens was the issue?
It just seems so strange that today it now works perfectly whereas the last 3-4 flights over a couple of weeks the problem happened every time the disconnect button was pressed.
I will see what happens next flight......


Alan.

 

[AlanR]

Well..
Four and half years later the problem with my Autopilot Disconnect has reared it's head again! Doing exactly the same thing as it did all that time ago!
It has worked perfectly every for all these years and all this time on every flight the Autopilot has been used. But now I have the same problem again as before and every flight for the last 2months.
No fault was found last time, it just started working perfectly ok and has done ever since....It is totally mystifying!
If you follow this thread from the begining with the screen shots it is exactly the same issue as before.
The Autopilot works perfectly and can be disconnected either on the Skyview panel or on Autopilot Module but if I press the remote Autopilot disconnect switch I get 'Trim Roll LF' and 'Slip Trim Nose DN' when pressing the button.

Just wondering if anyone has any new ideas or thoughts not previously discussed that would help at all please?

Thanks,

Alan.

 

[Rhino]

Are both displays on?
Are you using a trimamp?
What happens when you double click the switch?
Does it engage the autopilot as designed?
Is broken line detection installed? If so, what size resistor was used?
If you hold the switch down during startup, do you get the AP DISCONNECT STUCK message?

 

[AlanR]

Hi ,
Thanks for the input and questions.
In answer to your questions:-

Both displays are 'on'.

Trimamp?......I don't know what that is but my trims are wired through the Autopilot Button module giving me Autotrim.

Double clicking the disconnect switch doesn't make any difference.
Double clicking doesn't disconnect the autopilot and creates the 'Roll LF' and 'Slip DN' on screen notiification as in previous screenshots. I then have to press Autopilot disconnect on the Skyview or Autopilot button module to disconnect the Autopilot.

Boken line detection is installed as is a 5ohm resistor in the remote button disconnect line.

Pressing the remote AP disconnect button does nothing and nothing is displayed on screen if the Autopilot is not actually engaged.
The Autopilot works perfectly tracking and holding course, altitude and attitude perfectly and Autotrims the aircraft perfectly in all aspects.
Everything works fine if I just use the Skyview display 'Autopilot off' button. It is just the remote Autopilot disconnect button that produces the problem described and shown in the past screen shots.

As I said, I had this problem 4.5years ago as shown in past posts earlier in this thread...Nothing was done or changed at the time and the problem miraculously went away and has stayed away until now.when it is back again.


Alan.

 

[Stevec]

Could it be a bad earth connection. The switch to disconnect goes from the servos to ground when pressed. Perhaps find out where the ground connection is and clean it up most intermittent problems I have found have been due to earthing.

 

[Rhino]

Boken line detection is installed as is a 5ohm resistor in the remote button disconnect line.

I'm hoping that's a typo. Should be 4.7k - 5.3k ohm, not 5 ohms.

Did you ever try bypassing the switch, as kellym mentioned?

 

[AlanR]

Yes a typo...a 5k resistor is fitted and was replaced 4.5years ago as was the actual disconnect button replaced.
But at the time years ago the fault continued and then miraculously completely disappered until recently.

The button itself works because pressing it it actuates the fault of 'Trim roll LF and Nose DN'. All that can be done then when in flight is to press 'Autopilot off' on the actual Skyview.
The Autopilot works normally if immediately re-engaged.

Alan.

 

[Rhino]

I suspect your system, but everything else should be ruled out. Dynon will probably ask for that. That's why I'm asking the probing questions.

 

[AlanR]

I have been looking back at emails I exchanged with Don Jones of Dynon back in 2020. No conclusion was found at the time because the problem subsequently went away.
See below some email copy I sent to Don at the time following checking Config/Status etc.

'Hi Don,
Thanks for the reply..
I have checked the Config and autopilot status in setup.
Note:- I do not have at any time messages of 'Disconnect switch broken' or anything like that when the A/P is in operation in flight.
In status It shows disconnect button configured as it should but shows button not pressed. Pressing the button when not in A/P does not do anything but then I don't suppose it would anyway.
However, If I then put the A/P in 'Level mode', trying to simulate operating the A/P in flight, and press the disconnect button it still shows 'Button not pressed' but whilst still holding the disconnect button down it does stop the autopilot trying to level the aircraft, so button appears to be working, and again shows the Roll and Pitch indications as before in flight. (I did this in Config on P1 screen whilst viewing P2 screen) so could see that it showed 'Button not pressed' although pressing the button was clearly creating the Pitch/Roll indications on the Skyview.
See pics showing config and shots of when the disconnect button is pressed when in Level mode showing Pitch/Roll indications.
So my own conclusion so far is that the momentary disconnect button is working ok but somehow the Skyview is not responding and switching the Autopilot off from the remote button.'


Alan.

 

[Stevec]

I can’t help think that the strange result you are getting when the button is pressed is detracting from the cause of the problem. As someone has already suggested how about wiring a temporary switch from the servo to ground and disconnect the original switch. To me it would suggest that when you are pressing the button now there is a short or grounding via another route or means that is causing this issue. The fact that the problem disappeared and later returned would almost confirm this for me.
However that said I do tend to look at the most complicated solutions first and work my way back to the simplest most obvious