Sequence of Events
During cruise flight, the certified flight instructor (CFI) moved the fuel selector from the left to the right position. The engine RPM then began fluctuating. The CFI moved the fuel selector back, and the engine began operating normally but subsequently lost power. While descending in dark night conditions for a forced landing, the aircraft collided with a black net covering a nursery and the poles supporting the net.
Examination Findings
Examination of the cockpit revealed that the fuel selector was in the OFF position. It was confirmed that the fuel selector was not moved by fire or police department personnel. Inspection of the aircraft revealed that the right wing fuel tank flexible line, which attaches to the fuel tank, was partially blocked by contaminant. The line was manufactured in 1969. Additionally, the right wing fuel tank and carburetor finger screens were partially blocked by contaminant. The carburetor bowl was drained, which revealed that it contained less than approximately 3 ounces of fuel.
According to Note No. 18 of the Piper inspection checklist, the flexible fuel line is required to be replaced when the engine is overhauled. The engine overhaul occurred in 1984, and the flexible fuel line had not been replaced.
The passenger stated that he moved the fuel selector without the knowledge of the CFI and that he was at the controls at the time of the loss of engine power.