J3C 65 N11188 accident near Palmyra, Wisconsin

Probable cause

The pilot’s inadvertent pulling of the fuel shutoff valve, which resulted in a total loss of engine power and a subsequent forced landing into trees. Contributing to the pilot’s inadvertent pulling of the fuel shutoff valve were habit patterns he had developed from operating an airplane with different flight controls.

NTSB analysis

Two airline transport-rated pilots departed on a personal, local flight to practice maneuvers. While returning to the departure airport and on the downwind leg, the rear seat pilot inadvertently pulled the fuel shutoff valve, which resulted in a total loss of engine power. The front seat pilot attempted to push the fuel shutoff valve back in but was unable to do so. The rear seat pilot then conducted a forced landing, during which the airplane impacted a tree about 2,000 ft short of the runway threshold, which resulted in substantial damage to both wings.

Earlier in the year before the accident, both pilots frequently flew an airplane with a carburetor heat control that was in a similar position as the accident airplane's fuel shutoff valve. The rear pilot stated that he may have inadvertently pulled the fuel shutoff lever instead of the carburetor heat control. Therefore, it is likely that habit patterns developed from operating an airplane with different flight controls contributed to the rear seat pilot inadvertently pulling the fuel shutoff valve.

Text from the NTSB. Open the NTSB docket for CEN18LA038 for the full record.