"John Kirksey" wrote in message news: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? Is there ever a time when
you would use carb heat as a preventive measure?

Partial carb heat without a carb temp gauge is generally considered a
bad thing. You may heat up the carb enough to develop ice deeper down.
Some planes heat the air in the intake before taking it in. The metal
Pipers (Warriors, etc) are famous for this. They really don't have any
carb icing problems. On the other hand, the tube and fabric Aeroncas
and J-3s will get carb ice in the time it takes to turn off teh carb
heat and advance the throttle (I know from experience ). Its not a
bad idea to cycle the carb heat on and off in cruise if you are flying
a plane that is known to get carb ice.
All my IFR planes have always been injected so I'm not sure how I
would feel about regular IFR flying with a carb unless I had a carb
temp gauge.

-Robert, CFI