What happened
On August 29, 2012, a Piper PA-23-150, registration N1486P, crashed approximately 3 miles southwest of Canton, Missouri. The flight departed from Pincklyville-DuQuoin Airport (PJY) in Illinois, en route to a private airstrip near Blakesburg, Iowa.
During the flight, the aircraft experienced a partial loss of power. A witness, a private pilot, observed the aircraft flying at approximately 2,000 feet on a northerly heading, noting that the left propeller blades were not rotating. The aircraft subsequently impacted a tree and terrain in an area characterized by rolling hills, woods, and open fields. The impact resulted in 2 fatal injuries to the pilot and passenger.
The investigation
The investigation examined the wreckage and the maintenance history of the aircraft. The left engine's oil, fuel, and pressure gauges showed zero or low readings, while the right engine's gauges remained within the operating range. The left engine's propeller blades were found in a low-pitch setting, and the left engine was separated from the wing.
Investigators examined the left wing gascolator bowl, which contained a blue silicon jell-type substance covering much of the area where a gasket is typically placed. No gasket was found in the gascolator. Testing revealed this substance was consistent with Permatex Blue RTV Silicone Gasket Maker, a product not recommended for use on parts in contact with gasoline.
Analysis of the engine spark plugs from the left engine showed carbon fouling on the No. 1, 2, and 4 cylinders, suggesting the pilot had attempted to use the fuel primer to restore power. The aircraft's takeoff weight was estimated to be between 3,540 and 3,756 pounds, which met or exceeded the maximum gross weight of 3,500 pounds.