performance after anti/deicing

[speed alive]

Good Evening together,
might be a stupid question and maybe very easy to answer:
Is the weight of e.g. type 4 fluid on the aircraft taken into account for the T/O performance somewhere??
You have performance tables for wet, contaminated or whatever runways, but wouldn't it make sense to reduce the RTOW after having the type 4 stuff on the A/C, for aerodynamic and weight reasons??

Best regards

[extreme P]

Theoretically Type IV will shed from the aircraft at 100 knots so no weight reduction will be require. You are probably correct that it will reduce acceleration just a bit but not enough to make a difference.

[Chesty Morgan]

Don't know what type you're on about but the Q400 had an incrememnt on the V speeds after de/anti icing with any type of fluid. IIRC it was about 7kts but I think it varied with flap setting.

Nothing else I've flown had or has the increment.

[AutoAbort]

But never heard about it before. I have ploughed through the AEA guide for deicing a number of times but never seen it mentioned yet. However it talks about Minimum amount of fluid to use on different aircraft for a sufficient Anti-icing capabillity, and for a medium sized jet it can be between 150-300 Litrers. Some of it flows off the wing during the spraying, some of it shears off during the takeoff roll. A guestimate would be that you have 100-200 kg of fluid on the aircraft until the point that it all blows off. How much this weight affects and aircraft of 20,000-60,000kg? I really don't know. On some aircaft if you have frost on the underside of wings you have to reduce the max weight by maybe 200kg. Does the shape of the fluid flowing down the wing have any resemblance to frost? I am sure research will continue and if proof can be found, Deicing tables/fluids/performance will be adjusted.

AutoAbort :ok:

[speed alive]

@extreme: I know it is a bit theoretical, but I just saw a video made by a pax who was on the AB flight that overshot the runway in DTM today and there you can see the deicing fluid flowing along the window, thats how this question came to my mind.

@chesty: no speed additionals on my type as well...

thanks for the answers guys