FBW A320 Trim Moves Back to Zero

[Konterhalbe 296]

I did my last MSFS flight on 06JUL, took a couple weeks break and since 31JUL I've got a weird trim issue with the FlyByWire A320 development version.

I was able to set trim to 1.0UP using the mousewheel, by grabbing the trim wheel with left click and the joystick buttons until 06JUL.

Now, when I try to set trim, it reverts back to 0 every time. I can't properly set elevator trim anymore, neither by mouse, nor by joystick.

This is the case in every phase of flight (takeoff, landing, etc).

 

I've also noticed, the mouse wheel controls the trim wheel in the aircraft differently than it did before.

Previously, when scrolling the mouse wheel back, trim went UP, and mousewheel forward -> trim went DN.

Now, the trim wheel moves to UP in both mouse wheel directions but reverts back to zero.

Also by grabbing the trim wheel via click and drag, I can only move the trim wheel to +0.5UP and -0.5DN when ENG are off.

 

Auto trim option is set to off in MSFS menus, and there are no active failures shown in the FBW EFB.

 

What am I missing here? 🙁

[jcomm 5,991]

Use legacy Mouse mode on MFS options.

Resetting to neutral after landing is per Airbus Logic.

Edited August 14, 2022 by jcomm

[Konterhalbe 296]

Thanks for your reply @jcomm

I'm not sure if this is the right mouse mode setting you've been talking about but it's on default and has always been in my sim.

I can change this to "mouse profile" but I guess this doesn't do the trick.

 

 

In general options - accessibility, there's something called cockpit interaction system.

This setting is on legacy.

 

 

 

17 hours ago, jcomm said:

Resetting to neutral after landing is per Airbus Logic.

 

I guess it's no bug then?

But how can I do a second flight with working trim?

[jcomm 5,991]

28 minutes ago, Konterhalbe said:

In general options - accessibility, there's something called cockpit interaction system.

This setting is on legacy.

 

Exactly - that's what I though might be set differently in your case, but I see it's ok, so...

Quote

I guess it's no bug then?

But how can I do a second flight with working trim?

You set it again, the THS according to the INIT data for your new configuration.

But your problem is indeed an interesting one and I never experienced it. Might it be due to some axis having been assigned to pitch trim without you noticing it ? 

Edited August 15, 2022 by jcomm

[Konterhalbe 296]

10 minutes ago, jcomm said:

But your problem is indeed an interesting one and I never experienced it. Might it be due to some axis having been assigned to pitch trim without you noticing it ? 

 

That's a good hint!

Just searched keyboard, mouse and joystick control settings for "trim" and the joystick is has got assigned only ELEVATOR TRIM UP 4 and ELEVATOR TRIM DOWN 3.

Mouse has got nothing assigned to trim and keyboard RUDDER TRIM RIGHT CTRL + ENTER and RUDDER TRIM LEFT CTRL + NUM 0, ELEVATOR TRIM UP NUM 1, ELEVATOR TRIM DOWN NUM 7 and AILERON TRIM RIGHT CTRL + NUM 6 and AILERON TRIM LEFT CTRL + NUM 4.

 

15 minutes ago, jcomm said:

You set it again, the THS according to the INIT data for your new configuration.

That's exactly how I did it in the past ... 🙁

 

Guess I have to uninstall the A320 and reinstall it again. Maybe that solves this issue. 😊

[gdjak 176]

23 hours ago, Konterhalbe said:

Also by grabbing the trim wheel via click and drag, I can only move the trim wheel to +0.5UP and -0.5DN when ENG are off.

That's by design, there was a recent post on the fbw discord .. let me find it.

Quote

This complex system allows hydraulics to move the THS surface as commanded by flight computers through 3 electric motors, or manually. There is a mechanical link between your trim wheel, the electric and the hydraulic motors. But remember: if you lose green and yellow hydraulics, this link is useless! All you are going to get is the small movement of the trim wheel until you reach the hydraulic spool valves travel end points.

 

[Konterhalbe 296]

Ahh ok thanks @gdjak for quoting this post here for those who can't stand discord, like me 😂

 

The fact that I can't trim more than 0.5 up and down when ENG are off isn't a show stopper for me, just wanted to mention it here to see wether or not the A320 is supposed to behave so.

 

I've just uninstalled and re-installed the FBW A320, let's do some test flights 🙂

[gdjak 176]

Mousewheel trim has been logged as an issue in the experimental version a couple days back, grab and move should work fine though. Reinstalling won't help I'm afraid ;)

[Konterhalbe 296]

Is mousewheel trim also logged in the dev version?
Cause I'm not using the experimental one but the development version.

[gdjak 176]

Not explicitly, but it doesn't matter much - they know which update caused it.

[Konterhalbe 296]

Yeah nah reinstalling didn't change anything. You were right @gdjak 😂✔

Still not able to do a second flight w/o shutting down the sim and restarting it. 🙁

[Crocket 47]

Trim system was recently built from scratch and simulates now the real system. The zero reset is normal A320 logic (you can click and hold your mouse to stop it from unwinding if doing a touch and go as per real plane).
 

But you are right that the dev version which has not yet received the flight computers upgrade has a state machine bug locking the trim demand on first touchdown.

This is already solved in experimental, and will be in dev when all flight computers logic gets from exp to dev. 
 

Sorry for the inconvenience 😛

 

Edited August 16, 2022 by Crocket

[Konterhalbe 296]

Thanks a lot for the explaination @Crocket

 

I just reload the aircraft for the time being when planning a second leg right after arrival as a kind of workaround and it's all good 🙂
Thanks for your contribution (I guess you're a dev?)!

[Crocket 47]

Yup 🙂. We are slowly adding building blocks!

[Konterhalbe 296]

On 8/17/2022 at 10:53 AM, Crocket said:

Yup 🙂. We are slowly adding building blocks!

Trim works perfectly now in dev version when flying a second leg!
Thanks a lot! 🙂

 

(Also sorting VATSIM frequencies by Radar, Tower, Delivery etc is really cool!)