Trim values saturate to limits after long flights on AP. PLANE CRASHES G LIMIT

Bug Reporting Hub Aircraft & Systems
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ISSUE DESCRIPTION

Description of the issue:

Trim values saturate to limits after long flights on AP. The AP autotrim seems to control a different trim value than the manual trim. After long flights of AP trimming, touching 1 key for trim increment or decrement instacrashes the plane because of G-limit. The trim goes to 100% or -100% instantly.

Can’t touch trim after using AP, its ridiculous.

If applicable, which aircraft is experiencing this issue:
208b. maybe others.

[PC Only] Did you remove all your community mods/add-ons? If yes, are you still experiencing the issue?
no mods.

FREQUENCY OF ISSUE

How often does this occur for you (Example: Just once, every time on sim load, intermittently)?

ALWAYS

REPRODUCTION STEPS

Please list clear steps you took in order to help our test team reproduce the same issue:

1.long flight
2.AP level flight
3.disconnet AP and touch manaul trim. bye bye.

YOUR SETTINGS

If the issue still occurs with no mods and add-ons, please continue to report your issue. If not, please move this post to the User Support Hub.

What peripherals are you using, if relevant:
none

[PC Only] Are you using Developer Mode or have you made any changes to it?

no

[PC, MSFS 2020 Only] Are you using DX11 or DX12?

[PC Only] What GPU (Graphics Card) do you use?

[PC Only] What other relevant PC specs can you share?

MEDIA

Please add a screenshot or video of the issue occurring.

[END OF FIRST USER REPORT]

:loudspeaker: For anyone who wants to contribute on this issue, Click on the button below to use this template:

Do you have the same issue if you follow the OP’s steps to reproduce it?
•

Provide extra information to complete the original description of the issue:
•

If relevant, provide additional screenshots/video:
•

2

If this is happening with the Turtle Beach VelocityOne yoke, there is a firmware update to fix it.

3

no peripherals, mouse and keyboard only. trim is all keyboard

4

This just happened to me on at the end of a C208 4 hour medevac run. It was kinda my fault for having the power too low on alt hold, thus forcing the Autopilot to trim up.
It’s something to check before coming off autopilot. Also the yoke position, which can get forgotten since it mostly hidden.
There’s an aircraft-specific keybind for ‘Elevator trim position neutral’ on the 208 and the 172 which will be useful.

2 Likes
5

I can confirm that I have encountered this bug multiple times, with two instances resulting in crashes. In one case, I was able to recover, and in two other instances, I managed to hit the escape key and restart the mission. It’s very frustrating to complete a multi-hour flight only to crash on short final. I was able to recover by engaging the autopilot, which helped return the trim to neutral.

1 Like
6

Something similar here, I have to constantly do small adjustments of the throttle on a 1h long C172 flight because the aircraft attitude/speed was constantly changing. Also what is considered a “long AP flight”? Like 2.5 hours +?

1 Like
7

Sometimes I have the same with the C172. It’s independently from the device. Same issue with joystick, mouse or others. This happens not only with AP. Also when you are in carrer mode and skip with ALT-N then the trimm wheel is doing crazy things

1 Like
8

thanks all for replying. good to know its not just my keyboard glitching. its crazy how such a simple variable like trim values end up being so out of phase between manual and AP counts.

Its a simple line of code that SHOULD ONLY read one and update the other by increments. absolute values should not be allowed in the flight model.

please fix this Asobo.

9

your issue is a different issue. All the AP models on all planes are not tuned for good tracking. all planes wobble in AP. Different issue altogether. Someone at Asobo needs to sit down and tune the AP gains for each plane. It takes a bit of time but its not difficult. they just got so much to fix…

10

I don’t see that there is anything to fix.
Autopilots are not magic wands. If you ask the AP to hold altitude with inadequate power, all it can do is trim up. And of course this can result in hitting the limit. And if you just switch it off in this state you have to deal with the aircraft in that state.
It’s really an airmanship issue.
And the AP will wallow around following a course, perhaps excessively, especially the C208, and especially at low airspeeds. But again, just fly the plane and deal with it.

1 Like
11

zero reading comprehension.

12

Do you have the same issue if you follow the OP’s steps to reproduce it?
• Yes

Provide extra information to complete the original description of the issue:
• I see this on numerous instruments in the Vision Jet, for both VelocityOne Flightstick and Mouse. Instruments that revert to max/min every time they’re clicked on include:
- Vertical Speed: starts at 9,900 ft/min and has to be scrolled down
- Trim Wheel: goes to 20 degrees whenever clicked with mouse, also goes to max with flightstick after AP is used
- MFD zoom: zooms all the way out on click and has to be zoomed in each time

It seems this “reset to min/max” issue persists across many instruments on an axis.

1 Like
13

I seem to have gotten around the trim issue (by changing settings on my flight stick and handing trim as up/down buttons instead of an axis), but I will note that the other instruments only do this for my in VR. I tested in flat and was not able to reproduce

14

i dont have axis trim, only yoke. i have trim under “increment/decrement” on keyboard. Weird that you only get it on axis!

15

Do you have the same issue if you follow the OP’s steps to reproduce it?
• Yes

Provide extra information to complete the original description of the issue:
• no long flight is necessary, doesn’t matter how long and I think it’s mission dependent. Doesn’t happen in free flight. Also the unbinding of trim settings from keyboard doesn’t effect the outcome.

If relevant, provide additional screenshots/video:
•

I can confirm this bug with the 208B but only in career mode in a medium cargo mission. I think it is mission specific and not every mission is effected. Also the trim set to neutral command doesn’t work in these circumstances.
I am flying another mission right now to confirm my suspicion about it being mission specific.

1 Like
16

Okay. Just tried another mission and deactivated the AP in the middle of the flight. Sadly the trim wheel suddenly went all the way up (down trim) as soon as I did a input into trim. So this is definitely a bug and I am certain that it is effecting every mission now. Since these missions are a little bit long, I am not sure if I’m willing to try it again just to have that problem again. And there’s no way to come out of this weird behavior when the plane suddenly drops and goes crazy like that.
■■■■, I loved the career mode until now. But that is a game breaker for me. So no career mode until this is fixed or if someone can tell me what is going on.

1 Like
17

Okay. One last test on my side. Changed the trim settings from analog to the digital ones in the controller mappings - from “Elevator Trim Down/Up” to “Elevator Trim Decrease/Increase”. Will report back when I hopefully can manage the mission.

Cheers

1 Like
18

What controller do you have? If it’s a Turtle Beach VelocityOne yoke, there’s a firmware update for this. Mine used to do it too until I applied the update. Now it’s fine.

19

Culdn´t finish the test due to the midnight bug that happens at around 12am local time LOL.

But did test it in free flight just now. Weird enough the trim change in the mappings menu did nothing to the trimming of the C208B. That does not work at all for trimming. But I change the settings again and what you know, it happened right away with trim goes to 100%. But after that all was good. Tried a few mapping changes but nothing happened again. But I think it is a controller problem. I have to try tomorrow with my joystick on a different USB port and maybe even on a powered hub. I think it is a ghosting issue. Could be, kind of felt that way.

Got the X56 Hotas.

1 Like
20

So I am currently flying another cargo mission with the 208B. Tested shortly after some time after takeoff and after using simrate. Sure enough after AP off and just using a button to bring trim back to normal, the trim went crazy again and the plane went off the charts again. But after pressing the reset trim button a few times and engaging AP again, the plane was saved. So I now deleted my two buttons for trimming and will fly without trimming for now. Should be possible but as long at that bug still exist, I am not gonna use trim again.

Things I did beforehand:

Changed to a powered usb hub for my joystick to rule out any ghosting. Checked my power plans to make sure that every usb port could not be turned off by Windows. Also turned that option off for every USB thing in the device manager.

So my conclusions are:

it is not related to the time you’re spending flying. It is not mission related. It happens sometimes in free flight too. It’s not always happening after disengaging the AP.
And the specific mappings for elevator trim for the 208B don’t do nothing to control the elevator trim in the plane. Only the reset elevator trim to neutral works.

So flying without trimming it is for now. At least now I can fly again and don’t have to fear anything weird is going to happen. But what you know, we will see.

But I’ll keep an eye on that bug and will report from time to time.

Cheers

1 Like