Autopilot trouble when traffic around

Hi everyone. Lately I am experiencing problems when flying in busy airport while an event is going on. The aircraft is not capable of keeping the altitude and speed while in NAV or APP. But when using HDG and VS it works fine. Os there anybody else having this problems? I never had this problem before.


Have you noticed a difference between using APPR in a busy airport compared to a near-empty one? And what device are you running?


Yes, when in empty airports the APR works perfectly smooth. When I use it in busy airports I can forget about it, it will start going from side to side and up and down. If I use heading and vs it is way more precise. It never happened to me until yesterday as I said.

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That’s strange. Let’s see what @schyllberg has to say, he’s really good with this stuff :)

There are certain aircraft that AP does not work well with (eg. A321), and the fix is to set vs0 without setting alt. That might be what you are encountering.

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Yes that helps, but it happens in busy airport and not only with the 320, I tried many and same problem.

The AP functionality have no clue about surrounding aircraft, so I doubt that’s the case.

More likely what @xsrvmy said or similar to it :)

I have no problem when alone.

Just gonna add to that list, I’ve seen the problem on B77W, and to a lesser extent, Dash 8.

I’ve never seen the heading issue in an airliner though. Are you pushing F22 at full speed or something?

No, I have seen it also in 340 and 787, actually all airplanes I used since yesterday in busy airports.

I can show you replay, I will upload it to youtube and share here.

Seeing it in 787 seems weird. Can you send it to

You are right, with the 787 I didnt have trouble, I am going to try it now and report back. But with the 777 I never had problem and yesterday it was becoming crazy. The 320 is terrible.

You are almost stalling actually.

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Looks to me like you were too slow. Was this ILS/loc intercept? on base?
ILS intercept at 180-200 kias should work., flaps 2-3. Weight dependant

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Because of the pitch of the APR mode, I had to disconnect it to save it.

I intercepted at around 200kts and i made sure to leave it aligned with the runway within 5 degrees. But the autopilot went to a more than 10 degree roll for some reason.

Ok I see. A320/321 have some issues with APPR at the moment.
My best tip is to handfly approach until this is fixed

It is a 777

You should probably just change your flight plan and use NAV to align instead. I find that much more reliable.
Intercept at around 30 degree btw, not like 5.