What happened
A certificated commercial pilot and two passengers departed from a remote airport operating an air taxi flight. Shortly after takeoff, the pilot climbed the aircraft to approximately 1,000 feet MSL when the engine began to run rough. Despite the pilot performing emergency engine procedures, the roughness could not be corrected.
As the airplane began losing altitude, the pilot identified a suitable forced landing area within a slough. During the landing sequence, the aircraft collided with trees, resulting in damage to the wings, fuselage, and empennage. All occupants were not injured.
The investigation
Investigators examined a sample of fuel taken from the left reservoir tank. The sample appeared murky and silty and contained a small amount of water. Laboratory analysis determined that the fuel itself met all required standards for aviation fuel; however, the sample contained contaminants including silt, dust, microscopic fibers, and paint chips.
Following the recovery of the aircraft, the engine underwent a mechanical examination. No mechanical malfunctions were identified during the inspection, and the engine was capable of producing full power when tested on a test stand.