AutoTune gave up: the aircraft would not settle level

What ArduPilot says:

• AutoTune: Failed to level, please tune manually

Between twitches AutoTune waits for the copter to come back to level and hold its heading. It waited 6 seconds and the copter never settled: by then it has to be within 5° of level and of its heading, turning slower than 10°/s in roll and pitch and 15°/s in yaw, for a quarter of a second. AutoTune has stopped testing and you are flying on the gains from before.

What to do, most likely first

1. Wind or gusts keep pushing it off level.

   CheckIt happened on a breezy day, with the aircraft visibly leaning to hold its place.

   FixTune in calm air, early or late in the day.

2. The tune it starts from is too loose, or already oscillates, so the aircraft wobbles between tests.

   CheckHover before the tune: it should sit still, with no wobble and no slow rocking.

   FixGet a steady hover by hand first (the Setup & Tuning Guide's steps on oscillation and on roll and pitch by hand), then run AutoTune again.

3. Something keeps tilting or turning it: a load hung off centre, a bent prop or motor mount, strong vibration.

   CheckIn the log, compare the desired and the actual roll, pitch and yaw in the hover before it failed.

   FixBalance the load at the centre of gravity and fix the mechanics, then repeat.

After this failure, switching AutoTune off and on begins the whole tune again from the first axis.

Parameters to look at

Where to do it:Setup & Tuning GuideSetup & Tuning GuideSetup & Tuning Guide