CEN11LA530

The pilot said that the engine began to run rough after he leveled off from a descent, and shortly thereafter, it rolled back to idle power. The pilot established a glide to the nearest airport and attempted to troubleshoot the cause of the loss of power, but power was not restored, and he made a forced landing to a cornfield short of the runway. A postaccident examination of the carburetor and a test run of the engine revealed no evidence of pre-mishap mechanical deficiencies. The weather conditions at the time of the power loss were conducive to carburetor icing at glide and cruise power. The airplane was not equipped with carburetor heat.

On July 28, 2011, at 1650 central daylight time, N114DC, a Vans RV-4, sustained substantial damage during a forced landing near the Fort Worth Spinks Airport (FWS), Fort Worth, Texas. The airline transport pilot was seriously injured and the passenger was not injured. The airplane was registered to and operated by the pilot. A visual flight rules flight plan was filed for the flight that originated in Houston, Texas, about 1445. Visual meteorological conditions prevailed for the personal flight conducted under 14 Code of Federal Regulations Part 91. In a written statement, the pilot said that he initiated a descent from 8,500 feet to 4,000 feet to clear the Class B airspace around Dallas/Fort Worth International Airport. Upon reaching 4,000 feet, the engine began to run rough and rolled back to idle power. The pilot declared an emergency, established a best glide speed and headed toward Spinks Airport, which was 8.8 miles away. The pilot then tried to trouble shoot the power loss, but was unsuccessful. The airplane was not equipped with carburetor heat. When the airplane reached an altitude of 1,000 feet, the engine lost total power and the pilot landed short of the runway in a corn field. The airplane's left main wheel struck vegetation, which caused the airplane to tip on to its nose striking the spinner. Postaccident examination of the airplane by a Federal Aviation Administration (FAA) inspector revealed the firewall was bent. The inspector removed the spark plugs, established engine continuity, and confirmed the fuel tanks were half-full of fuel. The carburetor was removed and inspected by an FAA approved maintenance facility. No anomalies were noted with the unit and it was placed back on the engine. The engine was then test-run and produced rated horsepower. No mechanical deficiencies were noted that would have precluded the engine from operating normally at the time of the power loss. Weather at FWS at 1640 was reported as wind from 130 degrees at 6 knots, visibility 10 miles, clouds scattered at 9,000 feet, temperature 40 degrees Celsius, dewpoint 15 degrees Celsius, and a barometric pressure setting of 29.78 inches of Mercury. According to the Department of Transportation/FAA Carburetor Icing Probability Chart, the weather conditions at the time of the power loss were conducive to carburetor icing at glide and cruise power.