Grumman Acft Eng Cor-Schweizer G-164B N6774Q accident near Colfax, Washington

Probable cause

A partial loss of engine power due to carburetor ice as a result of the pilot's failure to use carburetor heat.

NTSB analysis

The pilot was departing for the first aerial application flight of the day and the airplane was loaded with fertilizer. The pilot did not apply carburetor heat during the ground idle or taxi. He stated that during the takeoff roll, the engine did not produce normal power. He attempted to dump the fertilizer before the airplane collided with terrain in a nearby field. Post accident examination of the airplane and engine did not reveal any mechanical anomalies. Review of the carburetor icing probability chart revealed that the temperature and dew point, 8 and -1 degrees Celsius respectively, were conducive to serious icing conditions at glide power.

Text from the NTSB. Open the NTSB docket for WPR10LA139 for the full record.