Auto Pilot

eddies

New Member
Joined
Aug 29, 2010
Messages
73
Location
Sydney Australia
Hi Guys,

Last weekend I was flying in moderate turbulence using the auto pilot and it was doing really well in all the thermals.

After about 1 hour I started getting pitch slip messages and shortly after that the auto pilot disengaged with a audible warning message.

When I tried to re-engage the auto pilot I got a pitch servo error and the auto pilot immediately disconnected.

What would cause this to occur?

Have I perhaps broken the shear pin on the pitch servo?

I tried to engage only the wing leveler but I could not get this to engage either.

Any suggestions on how to fault find this would be appreciated.

Eddie
 

dynonsupport

Dynon Technical Support
Staff member
Joined
Mar 23, 2005
Messages
13,226
The servo cannot detect a broken shear screw. You can only determine the shear screw is broken by a manual examination of the servo.

If you're flying within the engagement limits of the AP, either a fault has developed in the wiring to the servo, or the servo itself has failed. Please contact Dynon Avionics Technical Support to have a Return Material Authorization (RMA) opened for the servo if you determine that there is no fault with the wiring.

Hi Guys,

Last weekend I was flying in moderate turbulence using the auto pilot and it was doing really well in all the thermals.

After about 1 hour I started getting pitch slip messages and shortly after that the auto pilot disengaged with a audible warning message.

When I tried to re-engage the auto pilot I got a pitch servo error and the auto pilot immediately disconnected.

What would cause this to occur?

Have I perhaps broken the shear pin on the pitch servo?

I tried to engage only the wing leveler but I could not get this to engage either.

Any suggestions on how to fault find this would be appreciated.

Eddie
 

eddies

New Member
Joined
Aug 29, 2010
Messages
73
Location
Sydney Australia
The servo cannot detect a broken shear screw. You can only determine the shear screw is broken by a manual examination of the servo.

If you're flying within the engagement limits of the AP, either a fault has developed in the wiring to the servo, or the servo itself has failed. Please contact Dynon Avionics Technical Support to have a Return Material Authorization (RMA) opened for the servo if you determine that there is no fault with the wiring.

Hi Support,

What are the steps that I should follow to fault find this, I understand how to check the wiring but how do I fault find the servo?

Regards
Eddie
 

dynonsupport

Dynon Technical Support
Staff member
Joined
Mar 23, 2005
Messages
13,226
Eddie:

To check whether the shear screw is broken:
1. Get physical access to the servo.
2. With one thumb and forefinger of one hand, grasp the disc under the arm or capstan of the servo.
3. With the other hand, shake the controls connected to that servo.
4. While shaking the controls, you should feel a 1:1 movement of the disc with the shaking of the controls. This indicates the shear screw is intact.
5. If you DON'T feel the 1:1 movement, the shear screw is probably broken. Fill out the form at http://dynonavionics.com/shearscrew to request a replacement shearscrew.
 

eddies

New Member
Joined
Aug 29, 2010
Messages
73
Location
Sydney Australia
Eddie:

To check whether the shear screw is broken:
1. Get physical access to the servo.
2. With one thumb and forefinger of one hand, grasp the disc under the arm or capstan of the servo.
3. With the other hand, shake the controls connected to that servo.
4. While shaking the controls, you should feel a 1:1 movement of the disc with the shaking of the controls. This indicates the shear screw is intact.
5. If you DON'T feel the 1:1 movement, the shear screw is probably broken. Fill out the form at http://dynonavionics.com/shearscrew to request a replacement shearscrew.

[quote
Hi Support,

What are the steps that I should follow to fault find this, I understand how to check the wiring but how do I fault find the servo?

Regards
Eddie
[/quote]

Thanks for that.

Besides the possible wiring issue (things have been working fine for 3.5 years), what I was really after is how to fault find the issue with the servo engaging and disengaging. Is there a test procedure that I should follow?

Should I attempt to re-calibrate the servo, force a network rediscovery etc.

Eddie
 

dynonsupport

Dynon Technical Support
Staff member
Joined
Mar 23, 2005
Messages
13,226
Eddie:

At this point, for specific problems with specific aircraft, we recommend that you get in direct contact with Dynon Avionics Technical Support - 425-402-0433 or support AT dynonavionics DOT com.

Thanks for that.

Besides the possible wiring issue (things have been working fine for 3.5 years), what I was really after is how to fault find the issue with the servo engaging and disengaging. Is there a test procedure that I should follow?

Should I attempt to re-calibrate the servo, force a network rediscovery etc.

Eddie
 

eddies

New Member
Joined
Aug 29, 2010
Messages
73
Location
Sydney Australia
Eddie:

At this point, for specific problems with specific aircraft, we recommend that you get in direct contact with Dynon Avionics Technical Support - 425-402-0433 or support AT dynonavionics DOT com.

Thanks for that.

Besides the possible wiring issue (things have been working fine for 3.5 years), what I was really after is how to fault find the issue with the servo engaging and disengaging. Is there a test procedure that I should follow?

Should I attempt to re-calibrate the servo, force a network rediscovery etc.

Eddie

OK will do thanks

Eddie
 

Dynon

Dynon Staff
Staff member
Joined
Jan 14, 2013
Messages
14,231
Location
Woodinville, WA
Hi Eddie - I see a note that we talked to you on the phone this afternoon. If that's not the case, let us know - we may have inadvertently mistook another customer for you.
 

eddies

New Member
Joined
Aug 29, 2010
Messages
73
Location
Sydney Australia
Hi Eddie - I see a note that we talked to you on the phone this afternoon. If that's not the case, let us know - we may have inadvertently mistook another customer for you.

That is definitely not the case

Eddie
 

eddies

New Member
Joined
Aug 29, 2010
Messages
73
Location
Sydney Australia
Hi Guys,

I am still waiting for someone in support to respond to my questions?

I have sent 3 emails so far.

Regards
Eddie
 

Dynon

Dynon Staff
Staff member
Joined
Jan 14, 2013
Messages
14,231
Location
Woodinville, WA
Hi Eddie - We had our wires crossed here (we try to get back to every email within a day, and we took longer than that in this case). It looks like you've got a dialog going with our support team now. Sorry for the delay.
 
Top