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Originally Posted by moxiepilot  According to NASA, deicing fluid does not offer protection after Vr as the fluid is supposed to be shed. http://aircrafticing.grc.nasa.gov/courses.html
It also gets into the reasons for -FRDZ and the associated problems. I'm not disagreeing with you or your chief, just some added knowledge... |
Deice fluid mostly runs off the airplane at taxi speeds. AntiIce (the sticky green stuff, Type II, II, or IV) is designed to shear off the airframe prior to rotation. The reason being that most aircraft with anti ice systems built in, especially for the wing, are effective in flight, but not on the ground.
On the CRJ we can can use engine cowl anti ice one the ground, but we can only turn on the wing anti ice (it's a hot wing, so bleed air warms the inside leading edge) just prior to take off. That way it becomes effective as the anti ice fluid comes off the plane. The hot wing is effective for pretty much everything except SLD icing. Or FOM says something like, "if SLD icing is encountered (evidence of this is ice accumulating on the side windshield) exit the SLD icing conditions".
As far as freezing rain... We can go in -FZRA, but nothing more then that. Same thing with -PL. If it is more then "light" or there is any other precip attached, we are stuck. The thing to keep in mind though is that in the end, even if your winter ops manual says you have hold over times for a certain temp/precip combo, most have some wording at the bottom that states "the airframe MUST be clean for take off". If you have any doubt that with the current precip you're airframe is clean, even with a coat of anti ice on it, you SHOULD be covered if you decide to sit it out for a bit.
FYI, -FZRA and drizzle doesn't always constitute SLD.