Originally Posted by
lalbak
Actually, taxiing with wing anti-ice on is not allowed since it can end up boiling the fluid and therfore render the fluid no longer usable.
With the 700/900/1000 wing anti ice will not switch off automatically after lift off.
That's correct, if you've anti-iced with type 4 wing heat is not to be turned on until just prior to beginning the take off roll.
Not to derail this thread anymore but the point is to eliminate any chance of undetected frost or ice by requiring wing heat be turned on during taxi to the runway anytime temp is 5 deg C or less, even on a sunny clear day. This airworthiness directive was put out in 2008 by Canada and Bombardier, the manufacturer of the CRJ.