What happened
On August 18, 2012, an experimental amateur-built FW-190 1/2 scale replica, registration N149AM, crashed near the approach end of runway 13 at Columbus Metropolitan Airport (CSG) in Columbus, Georgia. The flight was a local personal flight under visual meteorological conditions.
At approximately 10:18, the pilot was cleared for takeoff from runway 24. After performing a touch-and-go landing, the pilot turned right for a downwind leg for runway 13. During this phase of flight, the pilot notified air traffic control of a partial loss of engine power and expressed the intention to land on runway 13.
Witnesses observed the aircraft flying at a low altitude, noting that the engine sounded as if it were running rough or operating on fewer cylinders. One witness reported seeing the airplane bank to the left at nearly 90 degrees, followed by a nose-down pitch. The aircraft subsequently stalled and impacted the ground approximately 157 feet from the runway 13 threshold. The pilot sustained 1 fatal injury.
The investigation
Investigators examined the wreckage of the single-seat, wood-structured aircraft. The flight controls for pitch, roll, and yaw were found to be functional and intact, with no evidence of pre-impact failure. The engine, powered by a 100-horsepower Continental O-200-A, showed no mechanical failure in the power train, air induction, or fuel metering systems. However, post-accident testing of the spark plugs revealed that five of the plugs produced a weak spark, a condition that could have been identified during a pre-takeoff engine run-up.
Analysis of the engine's lubrication system revealed ferrous and non-ferrous particles in the oil suction screen and housing. Additionally, the oil tank contained approximately 8 ounces of oil mixed with water.
Findings
At the time of the accident, the temperature and dew point were such that conditions were favorable for serious carburetor icing at glide power. The engine sounds reported by witnesses and the pilot's report of power loss are consistent with the effects of carburetor ice. The investigation could not determine why the pilot did not utilize the remaining runway length available on runway 24 to land the aircraft.