CEN20LA170

The pilot was making a cross-country flight and reported that, about 1 hour into the flight, the engine began to “rattle” and “vibrate.” The engine lost power but remained running with about 1,000 RPMs. The pilot recognized that the airplane could not maintain altitude and executed a forced landing in a field. Upon landing, the airplane nosed over and sustained substantial damage to the forward underside of the fuselage. No mechanical anomalies were found with the engine. The cockpit fuel selector was found in the left fuel tank position. Contaminated fuel was found in the left-wing tank. The source of the fuel contamination could not be determined. The carburetor was heavily soiled. Murky fuel and sediment were present in the gascolator sediment bowl. The airplane was operating in conditions that were conducive to serious carburetor icing at descent power. However, the carburetor heat knob in the cockpit was not engaged. The combination of contaminated fuel and possible carburetor icing likely resulted in the partial loss of engine power.

On April 30, 2020, about 1430 central daylight time, an Ercoupe 415-C, N2275H, sustained substantial damage when it was involved in an accident near Hallettsville Airport (34R), Hallettsville, Texas. The pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. After refueling, the pilot departed from Garner Field Airport (UVA), Uvalde, Texas, about 1330 with an intended destination of Eagle Lake Airport (ELA), Eagle Lake, Texas. The pilot stated that, about 1 hour into the flight, the engine began to “rattle” and “vibrate.” The engine lost partial power and was running with about 1,000 RPMs. The pilot started to fly toward 34R, which was 7 miles away, but realized that the airplane could not maintain altitude and would not make it to the airport. The pilot maneuvered the airplane for an emergency landing in a field. During the landing, the nose landing gear collapsed, and the airplane nosed over. Postaccident examination of the airplane found buckling was on the forward underside of the fuselage by the engine firewall, nose landing gear mount, and wings. Engine drive continuity was confirmed. Intake/exhaust valve functionality and cylinder compression was confirmed. No mechanical anomalies were found with the engine. The lower Nos. 1 and 4 spark plugs were found fouled and carbon bridged. The right-wing fuel tank was found nearly empty, the header fuel tank was about two-thirds full, and the left-wing fuel tank was almost full. The cockpit fuel selector was found in the left tank position. Unidentified contamination was found in a fuel sample taken from the left-wing fuel tank. A fuel sample taken from the pilot’s last refueling source (UVA) found no contaminants. The carburetor was heavily soiled. The carburetor and gascolator/sediment bowl contained sediment and murky fuel. The carburetor heat knob in the cockpit was found not engaged. According to the carburetor icing probability chart in Federal Aviation Administration Special Information Bulletin CE-09-35, with a temperature of 81°F and a dew point of 27°F, the airplane was operating within the range of serious icing at descent power.