Carb Heat: What's the deal?

[Big Pistons Forever]

I just got the May addition of Pilot on my i-pad. I always make a point of reading
the "Safety Matters" column which IMO is an excellent learning opportunity for every pilot, no matter what their experience.

The second accident profile was a Pa 28 that was forced landed after an engine failure. Since the engine was subsequently tested with no faults found, the flight was on December 27 and thus with a temp and humidity doubtlessly smack in the middle of the severe carb icing range, and the engine reportedly sputtered and refused to accelerate after a low powered descent, it is pretty hard not to conclude that carb ice was the most probable cause for the failure. And carb ice is totally preventable by the pilot.

If the engine does get a big dose of carb ice the engine will initially sputter as soon as the heat takes effect because of the thawed ice water going through the engine. The carb heat must be left on sufficiently long to clear the ice which may require up to 20 to 30 seconds of heat.

The good news was a successful forced landing was carried out with no injuries although the aircraft was heavily damaged. The pilot reported that he attributed his success to "frequent forced landing practice" which leads me to wonder if he had used some of that practice time to learn and practice how to keep the engine from failing in the first place the requirement to use all that forced landing practice for real, might have been avoided......