Strange movements in loiter

On the last flight, the helicopter moved around on its own as soon as it took off, even though there was no stick input in loiter mode.

There was no such problem on the previous flight, and the difference between the two flights was an optical flow sensor.

Therefore, the cause of the problem was assumed to be an abnormality in the optical flow sensor. However, when I checked the log, the optical flow sensor looked normal, and I was confused.

Therefore, the logs of the two flights are shared for assistance.

Thank you in advance for your help.


flight log
0909 flight log - Google Drive

This issue is believed to be caused by the poor performance of ESC’s governor in maintaining RPMs.

I assume this because the audible rotor noise in flight changed with the collective.

After switching to an ESC with better RPM maintenance, the issue disappeared.