Grumman G-164B N6628Q accident near Colfax, Washington

Probable cause

A total loss of engine power due to excessive wear in several carburetor components that led to a malfunction of the carburetor.

NTSB analysis

The pilot stated that the airplane was about 100 feet above ground level following takeoff when the engine lost power. He landed straight ahead in a muddy dirt field. During the landing roll, the airplane nosed over and the engine separated from the airframe. Postaccident examination of the engine core revealed no anomalies that would have precluded normal operation. Examination of the carburetor revealed that the bushings on the throttle shaft and pump stem were worn, which allowed excessive play. The economizer linkage was also found to be loose; there was evidence of fretting on the mating surface to the engine and around the mounting bolt holes. The carburetor fuel screen was clean. The floats exhibited hydraulic crush damage consistent with fuel in the bowl, and the accelerator pump was worn. Based on the findings of the postaccident examination, excessive wear of the carburetor likely led to the loss of engine power.

Text from the NTSB. Open the NTSB docket for WPR09LA227 for the full record.