wrote in message
oups.com...
A Lieberman wrote:

Never had icing, however, one lesson my CFI and I were in clouds right at
32 degrees. Water was beading up the windscreen, so as long as that was
happening, we were reasonably safe.

I wouldn't trust that at all. The collection efficiency for ice
increases as the surface gets narrower (towards the wind), so you can
have ice on your antennas when there's still water on your tail; ice on
your tail when there's still water on your wings; and ice on your wings
when there's still water on your windshield.

Fortunately, my Warrior (like most or all Piper PA-28 models) has an
outside air temperature gauge with a long metal probe sticking straight
out into the airstream from the middle of the windshield. Because the
probe is so narrow, ice will form on it before just about anything else
(except maybe the antennas, which I cannot see). I use it as my
early-warning device, and divert to warmer and/or dryer conditions as
soon as the first tiny piece of ice forms on the end of the probe.


All the best,


David


Whether the droplets are supercooled or not has nothing to do with
collection efficiency. Collection efficiency is simply the number of
droplets which impact a surface instead of going around it with the airflow.
Collection efficiency is a function of the mass of the droplets, airspeed
and the size and radius of the collecting surface. If the droplets hitting
the windscreen are not freezing (assuming the windscreen is not heated) then
the droplets hitting the tail are not freezing either.

Mike
MU-2