Use of Carb Heat

I've seen a couple of articles indicating that carb heat will not remove
ice; it's purpose is to prevent ice formation.

No personal experience, though...


"Larry Dighera" <LDighera@att.net> wrote in message
news:jm4pq0pmqi252243ih0rf17es5jbkto8q5@...
> On Tue, 30 Nov 2004 15:09:00 GMT, "John Kirksey"
> <john.kirksey@> wrote in <g20rd.14599$%C6.279@trnddc02>::
>
> >
> >My question is, in these or similar conditions, would you consider using
at
> >least partial carb heat to help prevent icing, or periodically turn the
carb
> >heat on to clear out any ice that may have formed?
>
> It depends on the recommendations in the POH for that aircraft type.
> For Piper PA28-* full heat is recommended.
>
> >Is there ever a time when you would use carb heat as a preventive
measure?
>
> In a Cessna 150/2 operating in conditions that cause carb ice whenever
> the carb heat is turned off, I use enough heat to keep it clear.

Bill Denton wrote:
> I've seen a couple of articles indicating that carb heat will not remove
> ice; it's purpose is to prevent ice formation.
>
Not true, it will certainly get rid of it *IF* you've got enough
engine heat left. What you may be confusing is that if you have
a long period of low power operation (such as having the engine
pulled to idle to simulate engine out), you may not have enough
heat to melt the ice before the engine stops for good.

"Bill Denton" <bdentonchi@m> wrote in message news:<7Padne3WTNZMCjHcRVn-rQ@rcn.net>...
> I've seen a couple of articles indicating that carb heat will not remove
> ice; it's purpose is to prevent ice formation.
>
> No personal experience, though...
>
If it's working correctly, carb heat should remove ice. Of the top
of my head, I can't remember the exact figure, but it's supposed to be
able to increase the temp of intake air by 60F or more.

I can personally attest to the fact that it works. Usually what
happens is that the carb heat melts the ice enough to loosen it from
the venturi wall, then the engine swallows it. This can cause a few
seconds of engine roughness and has been known to cause some worry in
those experiencing it for the first time.

John Galban=====>N4BQ (PA28-180)

Andrew Sarangan wrote:

> And if the engine does stop the ice should melt on its own if the ambient
> temperature is above freezing. Then you can restart the engine :-)
>

If you don't hit the ground first.

This was actually one reason some suggest doing simulated engine outs
with the mixture closed (real engine out). It won't ice up with no
fuel being atomized.