AP Lateral Oscillations

[thierryd]

It is infrequent but I have seen this issue several times now. While flying along the programmed flight path, with the autopilot (AP) on, the plane will not follow the direct track to the next waypoint but oscillate away from the track then back to the track then away...
The "workaround" when this happens is to force a Direct To the next waypoint (which is already the current waypoint) and then everything seems to return to normal. I don't remember the exact wind component at the time but it didn't seem out of the ordinary (most likely cross wind though).

Here are some pictures illustrating the issue:

[michael1508]

Hi Thierry,

I have had the same behavior also once.
Not sure, what could trigger this. Maybe Jean Luc has an idea.

[bbruechmann]

I noticed this aswell. It seems especialy on steeper turns the FMS/AP struggles to get back on track again. If you have a stronger crosswind additionaly it´s worse. It seems the AP is struggling to compute the correct interception point while take crosswind and windcorrection angle into account.

[thierryd]

Thanks to both of you for confirming that you have seen the issue as well.