Teacherjh wrote:

Actually, I got in a situation in a cherokee (a 1980 Dakota) where the engine
was icing up and quitting just on the taxiway. By the time I got to the runup,
the engine just died. Happened a few times, had the thing looked at, the
conclusion was carb ice. On the ground, no less.

The main reason you don't need to habitually use carb heat with a Lycoming
is the fact that they run the induction tubes through the oil sump. When
the engine is warm, the hot oil tends to keep the carb warm. The situation
you describe (cold engine, near-closed throttle plate) would be perfect for
formation of carb ice if the humidity were high.

George Patterson
The optimist feels that we live in the best of all possible worlds. The
pessimist is afraid that he's correct.
James Branch Cavel