Airbus : Wing anti-ice on after Ground De-icing

[C.M]

I have read in some Anti/ deicing training documents , that setting wing anti-ice on after application of anti-icing fluid should be avoided because it changes the properties of the applied fluid and reduces its effectiveness.
Such statement of caution is not found however in airbus manuals . Are you aware of anything restrictive on this issue for airbus ?

[gnarlberg]

airbus wing anti ice on A320 doesn't work on ground.

[EGPFlyer]

...Apart from a 30 second test. The reason is that the slats would get too hot without any airflow and there is the possibillty of damage

[C.M]

I’m fully aware of how the system works (the 30s test) .And the 30s test is short enough not to damage the slats that’s why it’s allowed to utilize this function on the ground. But my question only relates to its use after anti-icing fluid has been applied . Will the 30s test be enough to start altering its properties and start dimishing its holdover time? Whereas not using wing anti ice after fluid application is a common advise for anti ice procedures I couldn’t find anything from Airbus itself .
It came up in a simulator session . There was the suggestion from the examiner to utilize the test function just before departure to ensure it works (this was after antiicing procedures). I pointed out that the general advise is not to use wing anti ice after fluid application for the reasons I stated above. He told me to investigate if airbus has any such consideration because he wasn’t aware of any. Truth be told I could not find any from airbus either . But you never know if it’s hidden somewhere.

[Who stole my meds]

Possibly the best way to avoid potentially changing the properties of the de-icing fluid would be to test the wing anti-icing system (30 sec test) immediately after engine start, confirm it works, then turn it off until airborne.

[FlightDetent]

There is no AFM requirement, neither an FCOM procedure, to perform such test.

Navigating the Airbus document set is tricky waters at times. Your drive to double check before believing what you see is very prudent. Whenever I did it served me well, and v.v.

(On a previous type wing AI would operate continuously on GND if selected on, and we had a caution in the manuals no to use it after application of fluid, similar to what’s been said above.)

. I do not think there is any Airbus OEM guidance, or they would bother issuing one, as this is a complete non-issue
. should the company insist on verifying the correct operation before use (*), why not be smart about it and do it before spraying? The places you’d get de-iced before engine start are extremely few.
. maybe the esteemed TRE was trying to pass on knowledge, and ventured too far beyond the bookshelf? That’s an easy slip when the trained crew comes thoroughly prepared and they already understand well what is in the manuals.

* = such steam gauge, late 60’s philosophy had been designed out of this aircraft. Think STBY compass movement check.

[Highway1]

The 30s test isnt long enough to significantly heat the structure (which is why it is allowed on the ground) so it wont alter the characteristics of the de-icing fluid if that has already been applied. If you leave it on permanently on the ground then the surrounding structure heats up to the point where the de-icing fluid becomes less effective and you start damaging the airframe.

[applecrumble]

As a bit of an aside it is worth noting that if the wing anti ice is tested on the ground then you have to be sure to turn it off as otherwise as soon as you get airborne the valves open and that would invalidate your perf.

[C.M]

Yes it would invalidate you climb out performance . And since you mentioned this specifically , I have the following question .
Why does airbus takeoff FLYSMART module allow a take off calculation with the following A-ICE configuration : Engine & Wing ? ( You will see it offers different ASD distance than the other 2 cases which are ‘OFF’ and ‘ENGINE ONLY’ ).

[EGPFlyer]

Theoretically, you could turn it on as you start your takeoff roll.

[C.M]

You could but since you shouldn’t , Airbus should either not offer this as an option or have some red label there ( just like in some other fields ) . An allowance for ASD calculation under this setting is not something I expected to see.

[Uplinker]

@C.M.

Check your MEL. Airbus allow a take-off with the left/right wing anti ice valve failed open.

There is an operational procedure which changes the engine bleed configuration, so there will be performance differences.