Hi iniBuilds team,

First, congratulations on the A380 release — the dynamic wing flex is genuinely

impressive, and it is precisely what makes the first request below stand out.

Test footage, exterior camera on the left wing throughout:

https://youtu.be/kme2zIC2gs4

Version 1.0.0 (Marketplace), MSFS 2024.

REQUEST 1 — Load Alleviation Function (LAF), and wing-mode damping

(footage from 00:15 to the end)

Observed: wings level, repeated pitch inputs to excite the wing, then stick

released to neutral. The wing keeps flexing through a pronounced wave,

exactly as your flex model is meant to do — and the three ailerons stay

completely fixed for the entire oscillation. No reaction of any kind.

On the real aircraft the LAF is triggered on vertical load factor, measured

by accelerometer units on the engine pylons, and deflects the ailerons

symmetrically UP to unload the outer wing and reduce the root bending moment.

It is composed of Passive Turbulence Alleviation and Active Turbulence

Alleviation, active above given speed and load-factor thresholds and

inhibited in full slat/flap configuration.

The test case above is exactly what it exists for. As it stands, the flex

model and the aileron channels appear not to talk to each other at all —

which is a shame, because the flex model is the hard part and it is already

done.

REQUEST 2 — The VDA middle-aileron transient

(footage from 00:00 to 00:14)

Observed: roll inputs produce differential deflection across the three

surfaces — that part is already correct — but no transient on the middle one.

Documented by Claude Lelaie, Airbus experimental test pilot, in "A380:

Development of the Flight Controls" (Airbus Safety First)

On 27 July 2005, flight 51 out of Toulouse in strong southerly wind and

turbulence, the crew was very active on the stick; aileron activity produced

unpleasant lateral accelerations, felt mainly in the rear of the cabin.

Retuning gains and damping did not fix it. In mid-October 2005 new PRIM

computers were delivered with a new aileron law the design office nicknamed

VDA — "Valse Des Ailerons", the aileron waltz. Its purpose was to break a

coupling between two wing oscillation modes whose frequencies had become too

close.

For a left roll input, on the left wing:

- inboard aileron : moves up immediately

- outboard aileron : moves up as well, to a different deflection

- middle aileron : either goes DOWN first, in opposition to the other

two, then reverses upward; or goes up after a short

delay, passing through neutral

Since your channels are already differentiated, this should amount to a

transient shaping term on the middle-aileron output only.

QUESTIONS

1. Is LAF (PTA/ATA) on the roadmap, or does no load-factor feedback reach the

aileron channels by design?

2. Does the roll law carry any middle-aileron transient today, or are the

three channels differentiated by gain alone?

Happy to record further test cases on request. Thanks for considering it.

Edited Friday at 09:39 AM4 days by bigmousse

There is no LAF? I hadn't even noticed that. That's really important—why doesn't it exist?

8 hours ago, bigmousse said:

Hi iniBuilds team,

First, congratulations on the A380 release — the dynamic wing flex is genuinely

impressive, and it is precisely what makes the first request below stand out.

Test footage, exterior camera on the left wing throughout:

https://youtu.be/kme2zIC2gs4

Version 1.0.0 (Marketplace), MSFS 2024.

REQUEST 1 — Load Alleviation Function (LAF), and wing-mode damping

(footage from 00:15 to the end)

Observed: wings level, repeated pitch inputs to excite the wing, then stick

released to neutral. The wing keeps flexing through a pronounced wave,

exactly as your flex model is meant to do — and the three ailerons stay

completely fixed for the entire oscillation. No reaction of any kind.

On the real aircraft the LAF is triggered on vertical load factor, measured

by accelerometer units on the engine pylons, and deflects the ailerons

symmetrically UP to unload the outer wing and reduce the root bending moment.

It is composed of Passive Turbulence Alleviation and Active Turbulence

Alleviation, active above given speed and load-factor thresholds and

inhibited in full slat/flap configuration.

The test case above is exactly what it exists for. As it stands, the flex

model and the aileron channels appear not to talk to each other at all —

which is a shame, because the flex model is the hard part and it is already

done.

REQUEST 2 — The VDA middle-aileron transient

(footage from 00:00 to 00:14)

Observed: roll inputs produce differential deflection across the three

surfaces — that part is already correct — but no transient on the middle one.

Documented by Claude Lelaie, Airbus experimental test pilot, in "A380:

Development of the Flight Controls" (Airbus Safety First)

On 27 July 2005, flight 51 out of Toulouse in strong southerly wind and

turbulence, the crew was very active on the stick; aileron activity produced

unpleasant lateral accelerations, felt mainly in the rear of the cabin.

Retuning gains and damping did not fix it. In mid-October 2005 new PRIM

computers were delivered with a new aileron law the design office nicknamed

VDA — "Valse Des Ailerons", the aileron waltz. Its purpose was to break a

coupling between two wing oscillation modes whose frequencies had become too

close.

For a left roll input, on the left wing:

- inboard aileron : moves up immediately

- outboard aileron : moves up as well, to a different deflection

- middle aileron : either goes DOWN first, in opposition to the other

two, then reverses upward; or goes up after a short

delay, passing through neutral

Since your channels are already differentiated, this should amount to a

transient shaping term on the middle-aileron output only.

QUESTIONS

1. Is LAF (PTA/ATA) on the roadmap, or does no load-factor feedback reach the

aileron channels by design?

2. Does the roll law carry any middle-aileron transient today, or are the

three channels differentiated by gain alone?

Happy to record further test cases on request. Thanks for considering it.

Hi,

Thanks for your detailed report. I will forward this thread to the team for further clarification.

Thanks for your patience!

Hello, and thank you to the entire team for the time and energy put into releasing such a great add-on. I imagine it will continue to evolve, and I hope they can do so without running into simulator-related constraints. The Airbus A350 had its charm with the sound of the flaps, and the A220 had that iconic "whale" engine sound; as for the A380, seeing the famous aileron system—the LAF—in action would be pretty cool It would also have its own charm. provided the simulator makes it possible, of course.