Carb heat questions

Carburettor heat is something you’ll find on older piston engine aircraft such as the PA28 and Cessna 152. It’s used to clear ice from, or prevent ice from forming in the carburettor in the engine. Carburettor icing is a common cause of engine failure in the UK.

I receive many questions about my use of Carburettor heat because there are various schools of thought about it, and because my videos are watched worldwide, different climates require different processes.

One question I commonly receive from US viewers is: Why do you use carb heat during descent, or check it during the cruise.  These people often cite the POH which says to only use carb heat when carb ice is suspected.

To that question, I refer to the UK’s aviation regulator (the CAA) who, because of our climate and the prevalence of carb-ice accidents/incidents, advocate much more frequent and routine use of carb heat. Google ‘CAA safety sense leaflet 14 carburettor icing’ to find the advice.

The other common question I get asked from UK viewers is: Why do you switch carb heat off on short final?

I’ve been trained by various instructors, who advocate different approaches. There’s the those who advocate leaving it on and turning carb heat off as they go-around. Then there are those who advocate turning it off on short final.

Each method has merits and downsides.  If you’re a pilot undertaking training, then I would recommend you continue operating carb-heat in the manner in which you have been instructed and if you have any questions, then take them up with your instructor.