D180 A/P problem

Dave12 · #1 05-11-2014, 04:47 PM

The altitude hold feature of my a/p has recently gone awry. It appears that it has lost the ability to pre-select altitude and when the altitude is dialed in while in flight, it blows right through the target number. It is very abrupt and erratic when climbing and descending. It has also lost it's ability to prompt for trim (lower left corner-Trim up, down, etc.). I have checked all of the settings and compared them to my written notes and all is good. It has the latest firmware download. I am suspecting a servo? Anyone have experience with this?

Paris12Man · #2 05-11-2014, 07:58 PM

I'd call Dynon and explain issue. Maybe they can extract some info from your logs.

Tony_T · #3 05-11-2014, 08:55 PM

Hi Dave,

Have not had that particular problem but if you have not already; I would run thru the Configure DSAB, Servo Calibration and Servo Test steps starting on page 8-14 of the Installation Guide. The procedure will tell you on screen if the calibration is successful and it will go into SERVO TEST mode. It will tell you if the Servo Test is successful. If these are successful then I would set the pitch servo settings all to default. The default settings are shown in the picture on page 8-18. These tests only take a few minutes. Then I would fly the plane to see if the problem still exists.

After that, you will have a lot more data on hand when you call Dynon Support. They will probably ask you if you had a successful Configure DSAB, Servo Calibration and Servo Test anyway, so I would do it before calling.

RFSchaller · #4 05-11-2014, 10:57 PM

I'd check for loose wires too. Probably not the cause, but it's good to start with the easy stuff first.

Dave12 · #5 05-12-2014, 05:10 AM

Thanks Tony, Rich and Steve, I have completed the DSAB configuration and servo calibration, it was my first thought also. I am also suspecting a wire problem at the servo as I have not upgraded to the new connector. I will be taking a look at that this morning and if no luck, I will be calling Dynon when they wake up.

Peterk · #6 05-12-2014, 06:26 AM

Dave. Not that this should have caused a "sudden" problem, but you may want to update your software to 5.5 if you haven't already. It does some nice "settling" things to your AP.