Primary finding
Probable cause
A loss of engine power for undetermined reasons during approach.
Investigator assessment
Analysis narrative
The pilot was conducting a test flight of the unregistered amateur-built Fokker VI airplane, prior to registering it. While on the downwind leg of the traffic pattern, the pilot noticed that the engine "was not making proper power" and he subsequently performed a forced landing, during which the airplane was substantially damaged. Examination of the engine revealed no evidence of any preimpact mechanical anomalies.
Source record
Factual narrative
On September 30, 2007, at 1940 eastern daylight time, an unregistered amateur-built Fokker VI was substantially damaged during a forced landing in Morristown, Tennessee. The certificated private pilot was seriously injured. Visual meteorological conditions prevailed, and no flight plan was filed for the local test flight conducted under 14 Code of Federal Regulations Part 91. According to the pilot, he was conducting a test flight of the experimental airplane, prior to registering it. While on the downwind leg of the traffic pattern, the engine "was not making proper power" and "did not sound right." The pilot realized he would not make it to the runway, and performed a forced landing to a field, during which the airplane was substantially damaged. The airplane was equipped with a Two Stroke International engine. Examination of the engine by a Federal Aviation Administration (FAA) inspector revealed continuity within the fuel system, and the fuel pump was tested with no anomalies noted. The carburetor was observed "loose from the engine;" however, the separation was consistent with impact damage. The carburetor was disassembled and no anomalies were noted with the butterfly valve. The engine crankshaft was rotated at the propeller flange, and valve train continuity and cylinder compression were confirmed. The weather reported at an airport 31 miles to the northwest, 5 minutes prior to the accident, included calm winds, clear skies, temperature 21 degrees Celsius, dew point 6 degrees Celsius, and an altimeter setting of 30.34 inches of mercury.