Carb Heat in Engine Run up Checks
Did my PPL in USA during the engine run-up the school policy was 2,000rpm, L/R mag checks, carb heat check rpm drop, then with carb heat still on power to idle, carb heat off check rpm increase, then power to 1000rpm.
When I have had check outs at the other schools, I have been asked "Why do you leave the carb heat on when reducing power to idle?" Its seems uncommon everywhere else, most people just seem to test for rpm drop using carb heat at 1,700/2,000rpm.
The rational for idling the engine with carbheat on in the run up is that this will produce the absolute minimum rpm in the engine and therefore the engine is unlikely to cut out when you reduce the throttle to idle with carb heat say when practising stalls or on approach.
What method do other people use at their clubs?