Problem with autopilot at A321

Hi, I flew earlier today and I got some problems with the autopilot after takeoff. I sat the V/S speed to 2500 and the aircraft starts to climb with 6500 V/S per minute. I tried to turn off the autopilot and steered the aircraft manually instead. After 2 minutes, I tried AP again and it worked fine. What’s is the problem with the AP? It works perfect on all the other aircrafts, but not this? Have someone experienced the same problem as I?

Yep, the A321 is known to be one of the most unstable aircrafts in IF, only the bravest fly it…
Were you particularly heavy or were there heavy winds/turbulence around?

No, I think the weight was around 75000 kg and it was an north wind on 7 knots.

Welcome back, @CptAxel! Would you mind sending your replay file?

You can send one now at sharemyinfiniteflight.com. Save it to your Google Drive or iCloud, send the file to the website link above, save the link you uploaded the file in and send the link here.

We will take a look, a try giving out a few tips or advise on what could go wrong here. The situation on the A321 seems a little complicated. I also had issues before with the A/P on the Airbus A321.

Of course, I will do it later!

1 Like

Here is the link: https://sharemyinfiniteflight.com/download?c=EYCQVJJQQQ

I just took off no prob at 160,000 pounds and 8 on winds from the east, so I don’t see the problem.

This is a known issue as of yet no fix has been found as it affects some users but not all

Welcome back to the Forum @CptAxel! Hope you stick around.


This Is a known issue, and has been reported many times over and there are many similar topics covering this. No permanent solutions yet, but I’m sure the Developers have noted the issue.

1 Like

Hi, I couldn’t use your link to help out yet as I’m still trying to reactivate my subscription. In the meantime, have you had a thought about at what manual vertical speed you were at when you activate the A/P? I found out that while you could set ALT while still on the ground, the V/S will just copy whatever manual vertical ascend speed you were at the time. This has produced several stalls for me. So I always level out or at least have my vertical speed at 2400 ft/min - when you activate A/P ALT for example, that’s the exact V/S number that will automatically activates itself at the same time.

If you plan on flying the A321 I would suggest making sure you are able to supervise the whole flight and intervene if necessary.

In the days before I started flying the F-22 exclusively (The olden days) I had one or two close calls flying the A321. Upon reaching cruise I would go downstairs to get something and then return to the sound of stall and then overspeed warnings with the aircraft in a steep dive. I intervened before getting violations or crashing but it was close.

Manually lowering your VS the last 500-1000ft of climb is important to prevent this glitch. The A321 wants to level off to abruptly causing the porpoising effect which just gets worse and worse until this happens. The simple trouble shoot is to just lower your VS to around 200fpm-500fpm around 1000ft out of cruise. If the issue does arise a simple disengaging of the AP and then manually leveling off and re engaging the AP and having a slow climb of 100fpm back up to your cruise should resolve the issue.

I found that even when I levelled off manually at cruise altitude the porpoising would build up by itself with no obvious trigger. A tiny fluctuation in attitude is all that’s needed.

This topic was automatically closed 3 days after the last reply. New replies are no longer allowed.