Originally Posted by
piperboy84
PISTONS, do you do this?(keep the carb heat on till vacated) And how are you gauging "if conditions warrant carb heat" are you basing it on preflight weather reports and/or personal observations or pre landing OAT and visual cloud conditions or is there other factors you take into consideration when deciding to hold the heat on all the way down?
Well two of the aircraft I regularly fly have carb temp gauges which makes it pretty easy. If the carb temp is above 10 deg C then the carb heat stays off. I fit is below that I apply enough carb heat to get the temp up and out of the icing range.
If I am flying an airplane that does not have a carb temp gauge then environmental conditions dictate whether or not I consider carb heat. If, for example, it is dry and 25 C the carb heat isn't going on.
If it is in the well in the icing range then I monitor the engine for signs of icing and always select carb heat on in the prelanding check and look for any signs of the heat clearing any ice. If I do think there was some icing present then the carb heat goes back on and stays on. In conditions particularly prone to icing like wet air with temps between zero and 10 deg I keep the heat full on during the approach as a prophylaxis against icing.