Not about time, it's about conditions; i.e., engine anti ice is to be on
whenever visible moisture is present and the TAT is between +5 and -15,
or variations on that theme. Visible moisture is often clouds without
any apparent ice.

wrote:


Sam, required of anyone who operates Part 25....? thats exactly what
I'm looking for. I've not come across where it is required to be on a
set amount of time before entry.

Realize this refers to a set amount of time prior to entry in icing
conditions.

Dassault falcon series, and the lear series for Bombardier that I've
seen in their AFM's just say "prior", with no specific time
stipulated. If you've some other info I'd like to see it.

On Tue, 02 Dec 2008 06:23:41 -0800, Sam Spade
wrote:


It's not airmanship. It is required of anyone who operates Part 25
turbine aircraft. I presume it is in Part 25 somewhere. I'll leave
that for you to research. ;-)

wrote:

This is what I've always heard too. Just that some people say putting
a-ice on "just prior" to entering icing conditions is NOT good enough,
as surfaces will not be fully heated by the time icing conditions are
encountered. I can't argue with the airmanship side of that, and I'm
not. But I am inquiring if any manufacturer has specified "2 minutes
prior" or something like that.

Similarly, does far25 icing tests allow time for systems to heat up,
or were they done by turning on a ice systems "just prior" to entry of
icing coditions? Thanks Sam. Anyone else with insights?