Carb Icing

 

October 17, 2009

We are currently in a prime season for carb ice due to the cooler temperature and the abundance of moisture in the air.  Carburettor icing is one of the most frequent causes of unexpected engine failures during flight.  An encounter with carburettor icing is most likely when in moist air conditions and between temperatures of -5 and 30°C.  Severe carb ice can occur between temperatures of 5 and 15°C.

Remember as you are flying that if you have a gradual drop in RPM (for fixed pitch props), you are likely experiencing carb ice.  The correct response is to apply carb heat for approximately 2 minutes.  If there is no ice, there will be a crisp drop in RPM.  If there is ice there will usually be no immediate change, but this will be quickly followed by engine roughness as water from the melted ice is ingested into the induction system.

Remember to pull your checklist for a rough running engine as well!

Reapply carb heat as necessary!!  The last thing you want is an engine failure and a forced approach caused by carb ice!

 

Philip Craig

Safety Management Officer

 

This Flight Operational Notice was originally released in November 2008