On June 30, 2009, the FAA issued Special Airworthiness Information Bulletin CE-09-35 “to inform pilots of the potential hazards associated with carburetor icing.” The SAIB observes that the rate of accidents attributed to carburetor icing has remained steady over the years despite efforts by the FAA, AOPA and others to raise awareness. As a result, the SAIB briefly describes how a pilot may prevent and/or identify carburetor icing.
To prevent carburetor icing, the pilot should (1) make sure the carburetor heat works prior to takeoff; and (2) use carburetor heat on approach and descent when operating at low power settings, or in conditions where carburetor icing is probable. Carburetor icing can be identified by (1) a drop in rpm in fixed pitch propeller airplanes; (2) a drop in manifold pressure in constant speed propeller airplanes; or (3) roughness in engine operation in either type of aircraft. Once identified, the pilot should apply full carburetor heat immediately. The SAIB also concludes that pilots should consult the AFM or the pilot’s operating handbook for the manufacturer recommended use of carburetor heat in the applicable make/model of aircraft.
This seems like old news to me. I know when I learned how to fly, and when I have received advanced and recurrent training since that time, the procedures for identifying and dealing with carburetor icing have been covered. Maybe that isn’t the case for other pilots and I have just been fortunate to have top-notch instruction over the years. In any event, I guess a reminder/refresher isn’t a bad thing.