NTSB Identification: ERA10LA294
14 CFR Part 91: General Aviation
Accident occurred Tuesday, June 01, 2010 in Ashland, VA
Probable Cause Approval Date: 04/07/2011
Aircraft: SWANSON RV-9A, registration: N858JK
Injuries: 1 Minor.
NTSB investigators may not have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.
The pilot/builder was in the process of conducting the experimental airplane's 40-hour Phase 1 test flights. He departed his home airport and landed at an airport about 30 miles away without incident. Shortly after takeoff, the engine experienced a momentary sudden reduction in rpm. The pilot elected to return to his home airport and while en route the engine experienced additional sudden and intermittent power reductions. The pilot was able to restore power either by applying full throttle or the application of carburetor heat. With the airplane approximately 2.5 miles from his home airport, the engine rpm decreased again and the pilot applied carburetor heat without any affect. The engine ceased producing power completely and the pilot elected to attempt to lose altitude and perform a forced landing to the runway. The pilot overshot the runway and the airplane touched down in the grass past the runway surface and nosed over. A postaccident examination of the airplane and engine did not reveal any mechanical malfunctions that would have resulted in a loss of engine power. Removal of several of the engine's spark plugs revealed that they were dark in coloration, consistent with a rich mixture. A weather observation taken at the airport, about the time of the accident included, wind from 210 degrees at 10 knots, gusting to 19 knots, a temperature 30 degrees Celsius (C), and a dew point of 20 degrees C. Review of a carburetor icing envelope chart revealed that the reported temperature and dew point at the time of the accident was within the "serious icing" at glide power area of the chart.
The National Transportation Safety Board determines the probable cause(s) of this accident to be: The pilot's failure to obtain the proper touchdown point during a forced landing in gusting wind. Contributing to the accident was a total loss of engine power, likely due to carburetor ice. Full narrative available
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