Accident Summary
On July 7, 2013, at 1050 central daylight time, a Flight Design GmbH CTLS light-sport airplane, registration N549LS, was substantially damaged during a forced landing near Sandwich, Illinois. The commercial pilot and his passenger sustained minor injuries. The airplane was registered to and operated by a private individual under 14 CFR Part 91, operating on a visual flight rules flight plan. Day visual meteorological conditions prevailed for the pleasure flight, which departed Creve Coeur Airport (1H0), St. Louis, Missouri, about 0912, and was en route to Waukegan Regional Airport (KUGN), Waukegan, Illinois.
The pilot reported that as the flight descended through 4,700 feet mean sea level, the engine began to run rough and eventually lost complete power. The engine monitoring system indicated no fuel flow, despite the airplane having 16 gallons of automobile fuel available between the two wing tanks. Several attempts to restart the engine were unsuccessful. The pilot requested radar vectors to the nearest airport, but the airplane was unable to reach an airfield, and a forced landing was made into a cornfield. The nose and main landing gear collapsed during the landing, resulting in substantial damage to the forward fuselage.
Postaccident Examination
Two Federal Aviation Administration airworthiness inspectors examined the recovered airplane. The examination revealed ample automobile fuel to sustain engine operation. The carburetor heat control was found in the OFF position. The engine started and ran without anomalies for about 2 minutes, responding to throttle inputs with the electric fuel pump off. Further inspection of the fuel system filter, gascolator bowl, and carburetor bowls found no particulate or water contamination. No mechanical or fuel system anomalies were identified that would have prevented normal engine operation.
Weather and Carburetor Icing Information
The nearest weather reporting station, Aurora Municipal Airport (KARR), about 13 miles northeast, reported at 1052: wind 210 degrees true at 10 knots, visibility 10 miles, sky clear, temperature 27°C, dew point 19°C, altimeter 30.02 inches of mercury. A postaccident upper atmosphere model indicated temperature 17.2°C and dew point 9.9°C at 5,000 feet msl. The carburetor icing probability chart from FAA Special Airworthiness Information Bulletin No. CE-09-35 indicates a serious risk of accumulating carburetor ice at descent engine power settings. The FAA Pilot's Handbook of Aeronautical Knowledge states that when conditions are conducive to carburetor icing, carburetor heat should be applied immediately and left on until all ice is removed; partial heat or insufficient time may worsen the situation. A Transport Canada report, The Use of Automobile Gasoline in Aviation (No. TP 10737), notes that automobile fuel has higher volatility than aviation fuels, absorbing more heat during atomization and thus increasing the potential for carburetor ice at higher ambient temperatures.
Pilot Statement
When asked about carburetor heat use, the pilot replied that he had never used carburetor heat in the six years he flew the accident airplane. He also indicated that most of his flying experience was in fuel-injected airplanes, and his memorized emergency procedures did not include applying carburetor heat after a loss of engine power.