Extract from BASI Journal No.7 Autumn 1990.
Carburettor Icing:
Look again at the first little fact: `Ice is COLD and needs HEAT to melt it`.
So why one day that is conducive to icing, do we reduce power then pull carb heat on? Stupid really - we pull the power which reduces the heat available! The FAA in an Advisory Circular said: `Heat should be applied for a short time to warm the induction system BEFORE commencing descent.` Ever thought of putting the carb heat on as part of the base checks? Then you will be applying heat BEFORE power reduction.
And our second little fact: `somewhere you have a CLUE to tell you ice will form or has formed`.
.Did you get a definite RPM drop on the engine run?
.Did you check the carburettor icing probability chart to see if today is a good day for carb ice?
.Did you monitor your RPM, manifold and temperature gauges and determine what the indications could mean?
.Did you clear the carb of ice BEFORE you reduced power?
.Do you apply power FIRST in a go-around - then put carb heat to OFF?
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The above recommendations were published in 1990. 27 years on they are still current.
