On January 6, 2001, a Cessna 170A (registration N1703D) was involved in an aviation accident near Eastsound, WA. Investigators recorded the probable cause as: The pilot's failure to use carburetor heat prior to reducing engine power to idle while operating in serious carburetor icing conditions. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A pilot departed without checking temperature-dew point spread in carburetor icing conditions, did not use carburetor heat during flight, and experienced engine failure after applying carburetor heat and throttle on final approach.
Background
A pilot took off for a local personal pleasure flight without ascertaining the temperature-dew point spread. The conditions at the time were conducive to serious carburetor icing at climb, cruise, or glide power.
Flight Details
During the 10 minutes he flew around the local area with the engine set to a full-rich cruise power setting, the pilot did not activate the carburetor heat to check for ice accumulation in the carburetor throat. Upon returning to the airport to enter the VFR pattern, he reduced the throttle to idle and simultaneously applied the carburetor heat. After turning final and pushing the throttle forward to add power, he discovered that the engine had quit.
Post-Accident Inspection
A post-accident teardown inspection of the engine and carburetor established that fuel was present in those systems. There was no evidence of any malfunction or anomaly that would have contributed to a loss of power.