Jay Honeck wrote:

Very weird. In our plane, the carb heat is checked prior to take-off,
and never touched again. In fact, I've only activated carb heat once
in flight (in ten years and 1500 hours) in ANY flavored Cherokee -- and
that was just an experiment.

The only time I've experienced carb ice was in an Archer. Of course I
was at 11,000 ft in cool moist air, but I had never experienced it
before, so I was caught by surprise. I noticed that my IAS was slowly
dropping (like 3-4 kts in the last 15 minutes). The throttle was still
firewalled (which at 11K feet, is ~55%), but I looked at the tach, and
noticed that my RPMs had dropped too. (This was before I was instrument
rated, so I didn't pay as close attention to the gauges as I should
have.) Just as I started to consider panicking, I thought about trying
the carb heat. That resulted in an immediate revolt by the engine as it
swallowed the water from the carb. It actually sounded a lot like an
ice-crusher... After about a minute everything was running smooth again
and I turned off the carb heat. For the rest of the flight I paid
closer attention to tach and had to apply the carb heat several more
times (although less of an event than the first time). Eventually, I
just left the carb heat on for the remainder of the flight.

But I've never had a problem since, so it is not a common event at all.
Sometimes the conditions are just right.


-m
--
## Mark T. Dame
## VP, Product Development
## MFM Software, Inc. (http://www.mfm.com/)
"Madness takes its toll. Please have exact change."