Cessna 170 N2585V accident near Plainville, Connecticut

Probable cause

The pilot’s overflight of the landing runway during a forced landing after a loss of engine power. Contributing to the accident was the pilot’s inadequate preflight which resulted in his failure to detect water contamination of the fuel system.

NTSB analysis

The pilot stated that, as he reduced power, he incrementally increased the flap settings to 10, 20 and 30 degrees on the downwind leg on the west side of the runway. He added that he applied carburetor heat when he increased the flap setting to 20 degrees. At 80 mph, with 30 degrees of flaps extended and before turning to the base leg of the traffic pattern, the engine experienced a total loss of power. During the subsequent forced landing, the airplane flew from west to east across the runway, rather than turning toward the runway, and crashed in marshland on the east side of the runway abeam the numbers. The fuel system was sumped from three points, and each sample contained a significant quantity of water. The fuel system was drained, the airplane was serviced with fresh fuel, and an engine start was initiated. The engine started immediately, accelerated smoothly, and ran continuously without interruption. Examination of the seals around the fuel caps revealed that they were unserviceable, and no longer functioned as designed. Over 3 inches of rain fell between the previous flight and the accident flight and likely entered the fuel tanks through the seals around the fuel caps.

Text from the NTSB. Open the NTSB docket for ERA13LA276 for the full record.