Maintaining NAV heading while in PROF mode

[Guest TSE]

FolksI noticed lately that my 11 has some issues maintaining NAV heading while in PROF mode.She starts to bank left and then right trying to maintain NAV heading.I don't see this happening on a constant basis, it suddenly starts and then goes away after reaching the next waypoint.Anybody else seeing this ?ThanksJoerg

[downscc 1,327]

PROF means 'profile' as in vertical... the a/p NAV mode maintains lateral navigation."It suddenly starts" where? You mean at a random point in the segment then the next segment it is okay?No, haven't seen this one yet unless it is weather related. How much is the left and right banking? If you are seeing 2-3 deg then maybe the wind is shifting, if it is 8-15 deg then something is really upsetting her.A little more info please.

[Guest TSE]

I know that PROF is for vertical, however the issue does not occur when in ALT HOLD mode, that's why I mentioned it.Yes, at a ramdom point in the segment.I just had it re-occuring a few minutes ago and noticed that AsV was "injecting" some random turbulence at the same time.Once the turbulence was over, everything went back to normal.The banking is more than 2-3 degrees, usually between 5-10.Ok, I guess I answered my own question how to prevent this by disabling turbulence options both in FSX and AsV, however she seems very sensitive to weather compared to other add-ons.ThanksJoerg

[downscc 1,327]

Certainly kill the turbulence. This is modelled very poorly in MSFS. The default aircraft have flight dynamics someone in middle school could create, the dynamic flight models for the PMDG aircraft are much more realistic, and less forgiving of simplistic air models. But the problem is not the better models, but the lessor ones.

[Guest TSE]

Thanks DanThe flight dynamics are extremly good, she is a pleasure to fly.However I was not referring to the default aircraft but comparing to the 747X post SP 2.10 and the LDS763.Some of us were seeing the same issue in the 747 and 747X which was adressed in service pack 2.10 for FSX and 1.20 for FS9:"Tightened autopilot roll logic to improve lateral tracking behavior in turbulence"ThanksJoerg

[downscc 1,327]

Possible. I think (not certain) that the issue arose when Peter Dowson was tweaking FSUIP4 to arrest the FS WX machine. I was trying out his frequent (almost daily) updates and others discovered this anomoly in the 747X. I don't think that is an issue in the MD11, but again not certain. Regardless, that silly turbulence simulation is more trouble that it's worth.