G3X system, GTN 750 with 305 autopilot control head. Roll, pitch and yaw servos.
On a flight yesterday I noticed a tendency for the AP (GPS nav mode, internal GPS) to slowly roll side to side about 2 degrees left and 2 degrees right bank all the time. No heading changes. This is something new. I am still in phase 1. I should have tried in HDG mode as well as external GPS, but that did not cross my mind at the time. I know for sure this was not present on earlier flights on either internal or external GPS. It started about 30 min into the flight. On a coupled ILS approach it was dead steady the day before.
I also noted on a flight the day before in HDG mode that when I turned HDG bug more than 30 degrees, the turn would overshoot the new heading, then turn back and get to correct heading.
Dual ADAHRS, one to PFD and the second to MFD. I believe the ADAHRS are well mounted and passed vibration test first time round. No indication of mismatch.
These are my AP settings:
Roll: Max torque 100%, Roll servo gain 0.8.
I assume the pitch and yaw settings are not relevant, but I have it available should anyone ask.
Looking for help and advice.
Thank you.
Johan
On a flight yesterday I noticed a tendency for the AP (GPS nav mode, internal GPS) to slowly roll side to side about 2 degrees left and 2 degrees right bank all the time. No heading changes. This is something new. I am still in phase 1. I should have tried in HDG mode as well as external GPS, but that did not cross my mind at the time. I know for sure this was not present on earlier flights on either internal or external GPS. It started about 30 min into the flight. On a coupled ILS approach it was dead steady the day before.
I also noted on a flight the day before in HDG mode that when I turned HDG bug more than 30 degrees, the turn would overshoot the new heading, then turn back and get to correct heading.
Dual ADAHRS, one to PFD and the second to MFD. I believe the ADAHRS are well mounted and passed vibration test first time round. No indication of mismatch.
These are my AP settings:
Roll: Max torque 100%, Roll servo gain 0.8.
I assume the pitch and yaw settings are not relevant, but I have it available should anyone ask.
Looking for help and advice.
Thank you.
Johan