feat(a380x/fctl): Automatic THS trim after engine start or touch and go

[flogross89]

Summary of Changes

Adds auto THS trim after engine start or when performing touch and go.
Also, cleans up some XML for the pedestal and the visibility conditions for the magenta GW CG box in the PFD's pitch trim indicator.

Conditions for engine start:

• First engine is started and a hydraulic system (G or Y) is pressurized OR
• Ground spoilers become armed

Conditions for touch and go:

• On ground for at least one second
• Airspeed greater than 80kts
• One of the following actions performed: Flaps lever moved, ground spoilers disarmed or at least one thrust levers moved out of IDLE

Screenshots (if necessary)

References

Additional context

Discord username (if different from GitHub):

Testing instructions

1. Start cold&dark at gate
2. Perform engine start per SOP, THS trim should move automatically
3. Perform take-off, traffic pattern and touch and go. THS trim should move automatically during touch and go
   Verify, that magenta PFD pitch trim indicator is only visible after first engine started and HYD is pressurized, and disappears after takeoff (not visible for landing)
   Try to find reference videos to verify whether the trim speed is comparable. Look at the degrees per second, not the overall time.

How to download the PR for QA

Every new commit to this PR will cause new A32NX and A380X artifacts to be created, built, and uploaded.

1. Make sure you are signed in to GitHub
2. Click on the Checks tab on the PR
3. On the left side, find and click on the PR Build tab
4. Click on either flybywire-aircraft-a320-neo, flybywire-aircraft-a380-842 (4K) or flybywire-aircraft-a380-842 (8K) download link at the bottom of the page

[77W9940]

I know the code is still ready for review, but i had a bit of time so just wanted to try it out.

Engine start automatic THS:
https://github.com/user-attachments/assets/240ac7c7-6321-4efe-bfe5-1ff833cdf886

Touch and go:
This one I am not sure about, after doing the traffic pattern, on the approach, shouldn't LAND and FLARE be on the FMA? As well as ROLLOUT. Anyways, during touch and go, set flaps to FULL->3 and TOGA. The THS value on the SD was changing.

2025-02-08.22-26-47.mp4

[Ueeew]

@flogross89 I just wanted to give a few tips or improvements. The first thing I noticed is that process of setting the trim automatically takes way to long. In the real aircraft the process of setting the THS takes only about 2-3 seconds(Real video for reference). In the FBW it takes about 5 or even longer.
The second thing is that the purple box, indicating the optimal THS setting ,is IR only shown a few seconds prior to auto THS setting process (shown in video). In FBW the box is shown the whole time as long as THS setting is visible on PFD.
https://m.youtube.com/watch?v=uEgw2p8J0ZA&t=775s&pp=2AGHBpACAcoFDUEzODAgdGhzIHRyaW0%3D
The engine stat sequence is at minute 2:45. Unfortunately you may have to zoom a bit in to see the process.
hopefully this helps

[flogross89]

@aadee9940 Thanks a lot! Have you considered joining our QA team?
It seems you didn’t arm any approach mode for your landing, but instead followed the flight plan guidance down to the runway. Did you tune an ILS, and press APP to intercept LOC and G/S?
The FMA modes are untouched by this PR, so that also wouldn’t be related.

[flogross89]

@Ueeew Very helpful, thanks! Indeed, the speed is far too slow, might need to check my triggering mechanism again, I believe I have to use another method.
about the magenta box: Also well spotted, I suppose the GW CG comes from the FQMS, which only sends these values after engine start or some other condition. I‘ll investigate in my references.

[77W9940]

@flogross89 unfortunately I don't have access to the FBW server as before, but if the mods want to have a look at my appeal LMK 😊

Yeah it completely left my mind I have to program my automatics to get proper FMA modes on landing, my fault 😂.
It was a fully visual circuit so yeah, but I hope my test shows what you are looking for? (The THS trim moving on the SD)
Wasn't really sure if this was EXACTLY what you were looking for..

[flogross89]

@aadee9940 Ah, didn't know that. I'm not a mod so I don't know any details, but I trust their process. Yep, that's what I wanted to see,

@Ueeew I changed the trim triggering mechanism, it should now use the full available speed (which is limited by the PRIMs, so that should be accurate).

[Ueeew]

@flogross89 could you just merge the master again into this PR so that it’s up-to-Date. Thanks

[flogross89]

@flogross89 could you just merge the master again into this PR so that it’s up-to-Date. Thanks

Sure, done

[Fowl38]

@flogross89 I just wanted to give a few tips or improvements. The first thing I noticed is that process of setting the trim automatically takes way to long. In the real aircraft the process of setting the THS takes only about 2-3 seconds(Real video for reference). In the FBW it takes about 5 or even longer. The second thing is that the purple box, indicating the optimal THS setting ,is IR only shown a few seconds prior to auto THS setting process (shown in video). In FBW the box is shown the whole time as long as THS setting is visible on PFD. https://m.youtube.com/watch?v=uEgw2p8J0ZA&t=775s&pp=2AGHBpACAcoFDUEzODAgdGhzIHRyaW0%3D The engine stat sequence is at minute 2:45. Unfortunately you may have to zoom a bit in to see the process. hopefully this helps

We can see on your video, on the F/O's PFD that the THS took 11 seconds to be set (from 2min55 to 3min06 of the video).

[heclak]

After landing, should the THS FOR value move to the current GW CG value?

[flogross89]

After landing, should the THS FOR value move to the current GW CG value?

After landing, it should move to the maintenance position (zero degrees, neutral). This also happened before the PR since it’s the same behavior as on the a320s.

In case of go-around however, it will move to the GW CG position again

[heclak]

A few notes from an initial test.

1. Magenta line appears on the gauge once the display powers on.
2. The pink THS value only shows up a few moments after the trimming is completed. Based on the video, the THS value and magenta line should appear at the same time.

Can you confirm how should the THS trim behaviour be observed during a touch and go since the THS gauge doesn't appear during the touch and go? Should the pitch trim position be noted prior to takeoff and the pitch trim should return to the same pitch trim value during the touch and go?

[flogross89]

@heclak Thanks for testing!

1. Do you mean just the magenta line was visible, but nothing else? I discovered an issue with visible vs. inherit CSS properties, that should/could fix that. Didn't have time to check it in sim, sorry.
2. Didn't fully understand that, do you mean the automatic THS starts moving before the magenta GW CG values are being displayed? There could be one explanation for this: The Auto THS starts as soon as one HYD system is powered, the GW CG is displayed as soon as one HYD system is powered AND at least one engine is started (N1 > 15%). I believe our HYD systems are powered very early on, I don't know whether the engine-driven HYD pumps are completely accurate in that sense. If it's only a few seconds I'd disregard it for now, and check the HYD system in the future.

When the following conditions apply, the indicator should be shown during touch&go:

Did those conditions apply?

During touch&go, the pitch trim should be set to the optimal value w.r.t. the current GW CG, measured/computed by the FQMS.

[heclak]

This is how the gauge appears immediately after power on. I believe the magenta box/lines shouldn't be there?

Once the HYD is powered, the system starts trimming but the trim value that's usually on the right isn't displayed. It trims with the same visual state as above. And the magenta value on the right only appears AFTER the trimming is completed. Refer to the magenta numbers in the screenshot below. Based on the rough footage of the auto THS working in the reference video above, the magenta markings in the middle of the trim gauge and the THS target on the right should both appear at the same time once the HYD is powered?

I'll have to give the touch and go a try again. The indicator didn't appear for me, maybe one of the conditions wasn't fulfilled on my run.

[heclak]

I think the color of the text might need adjustment too? Looking through this video, maybe the text is white before the magenta lines appear?

https://youtu.be/p28erS6uWHE?si=PzILc6PvMB_cIwpD&t=1423

Edit: Ah. Never mind. I think the color difference is because of the magenta state issue.