Originally Posted by
DeadHead
How much frost are we talking about?
It's acceptable to take off with a small amount of frost on the aircraft wing. The rule of thumb most pilots use is if you can see through the frost to the skin of the aircraft then it is acceptable.
Anything thicker than that is usually when it's time to visit the deice pad.
Don't know where you came up with this propwash, but the FAA and most airlines operate under the "clean aircraft concept". That means NO frost of any kind on flying surfaces with the exception of a small amount under the wings at some carriers and some aircraft.