This thread has drifted away from the original subject of tail de-ice. To Mansfield's excellent discussion of size. Then to people who state that they have thousands of hours on specific types and have never used the wing de-ice. I guess it depends on your routes, obviously some here have never flown in the Canadian winter. Before widespread radar coverage and R-Nav approaches you could acquire quite a load of the white (or clear) stuff during a full procedure turn and subsequent circle-to-land operation. I have seen more than an inch of it on the radome many times.
So, in some environments, wing anti-ice is very necessary.
Now back to the subject of tail de-ice, I think Mansfield again hit on the answer, namely the design of the horizontal tailplane and elevators. There used to be a story in the folklore that when Boeing certified the B-727 they somehow attached 2X4's to the horizontal stabilizer leading edge to demonstrate that it was capable of controlled flight with a large quantity of ice there. Whether that was true or not I don't know but I do know that the reason you gave the DC-9 tail a shot of heat on approach was to ensure a clean edge when you extended landing flap. Ice would act as a spoiler blanking the flow to the elevator. Not sure if it was in the manual but it was well known in the DC-9 community that if you ran out of elevator after selecting flap to 50° the solution was to retract the flap one step back (to where you had had control).
If you think about it, the wing generates the lift that keeps you flying so ice could be critical there - ergo, get rid of it. But the tail only creates "lift" (down or up depending on CofG) for longitudinal balance purposes. Its other purpose is to provide a home for the elevator. So if you make the elevator big enough that it is still effective even with a badly contaminated stabilizer, you don't need to remove the contamination. That must be what Boeing (and others?) have done.
Does that make sense?
Edited for grammar, colonials are slow but we do know!
Last edited by Idle Thrust; 1st Mar 2010 at 00:07.