WPR09LA117

The flight instructor and student were performing a series of touch-and-go pattern operations. The instructor reported that the engine lost power during the initial climb. He took control of the airplane from the student and verified that the mixture was fully enriched and the fuel shut off valve was in the "on" position. These actions had no effect, so he executed a forced landing in a nearby field. During the landing roll, the nosewheel sunk into the soft ground and the airplane nosed over and came to rest inverted. A postaccident examination of the engine by a licensed airframe and powerplant mechanic revealed that the bottom spark plugs of the number one and four cylinders exhibited evidence of water. Water was observed within the fuel sump; however, no water contamination was found in the fuel drained from the airplane's tanks. The engine was successfully run at various speeds with no anomalies noted. Review of the carburetor ice probability chart revealed that the temperature and dew point near the time of the accident were conducive to serious icing at any power setting. The instructor did not report applying carburetor heat following the engine failure.

On February 18, 2009, about 1000 Pacific standard time, a Cessna 152, N48761, was substantially damaged during a forced landing shortly after takeoff from the Turlock Municipal Airport, Turlock, California. The flight instructor was not injured, and the student pilot received minor injuries. The airplane was registered to, and operated by, KS Aviation, Inc., Atwater, California. Visual meteorological conditions prevailed for the local instructional flight conducted under Title 14 Code of Federal Regulations Part 91. No flight plan was filed. The flight instructor reported that he and the student pilot were conducting a series of practice touch-and-go landings. During takeoff initial climb following the fourth landing, about 100 feet above ground (agl), the engine lost power. The flight instructor took control of the airplane and verified the mixture was fully enriched and the fuel shut off valve was in the on position. He executed a right turn of about 50 degrees and initiated a forced landing in a rough, soft field. During the landing roll, the nose wheel dug into the soft terrain. Subsequently, the airplane nosed over and came to rest inverted. Examination of the airplane by operator revealed that the vertical stabilizer and rudder were crushed, the firewall was bent, and the propeller was damaged. The airplane was recovered from the accident site to a hangar at the Turlock Airport and examined by an Airframe and Powerplant (A&P) mechanic employed by the operator. The mechanic reported that the wings were removed during recovery, but the fuel lines were capped. The mechanic drained the fuel from the airplane's wing tanks, and found no water. During examination of the engine, he noted that the bottom spark plugs of the number one and four cylinders exhibited "evidence of water." Additionally, the mechanic found water and fuel in the fuel sump, although the water "was not high enough to reach the screen." In order to perform an engine run, the mechanic replaced the damaged propeller and jury-rigged a fuel supply using fuel drained from the airplane. The mechanic stated that the engine was started and run at various speeds with no anomalies noted. The nearest weather reporting station at the Merced Municipal Airport (MCE), located 15 nautical miles southeast of the accident site, reported at 0953, temperature 9 degrees Celsius and dew point 6 degrees Celsius. Plotting these values on a carburetor ice probability chart indicated that the conditions were conducive to serious icing at any power setting. The operator's chief pilot stated that the company believed "the engine stoppage was the result of carb ice." He further stated that their "procedures for operations include the proper application of carb heat," and these procedures would be reviewed with their instructors and students.