BFO96LA037

An instrument flight instructor (CFII) and an instrument rated private pilot were on a dual purpose mission to obtain an instrument compentency check along with a business flight. The pilots reported that they noted evidence of carburetor ice during the flight; therefore, as they began their descent to the destination, they elected to use carburetor heat throughout the remainder of the flight. The pilots reported that as they initiated a missed approach procedure, the airplane engine began to lose power. They began maneuvering for an emergency landing, then the engine lost power completely. The CFII took control of the airplane and maneuvered the airplane to avoid a treeline during the landing. Subsequently, the airplane struck the ground in a snow covered field, while in a right wing low attitude. Both pilots stated that they believed the loss of engine power was due to carburetor ice. However, they were flying in conditions of snow, and 23 miles south at Zanesville, OH, the temperature and dew point were reported to be 19 and 14 degrees F, respectively. According to icing probability charts, conditions were marginally conducive (borderline) for carburetor ice. Postaccident engine examination and a test run revealed no evidence of a preimpact mechanical malfunction.

On January 9, 1996, at 0950 eastern standard time, a Piper PA-28-181, N9248K, sustained substantial damage when it collided with terrain during a forced landing near Coshocton, Ohio. The certificated instrument flight instructor (CFII) and the instrument rated private pilot reported no injuries. Instrument meteorological conditions prevailed for the flight, which operated on an instrument flight plan. The flight originated in Ionia, Michigan, at 0755 eastern standard time, with an intended destination of Coshocton, Ohio. The flight was conducted under 14 CFR 91.

The private pilot reported that the "...flight was dual purpose; I needed an [instrument competency check], and it was convenient to make a sales call to a client in Coshocton... ." He stated that the en route phase of the flight was uneventful, although they occasionally noted evidence of carburetor icing. The private pilot stated that as they began their descent, due to observed and reported icing conditions, the pilots "...elected to use carburetor heat for the remainder of the flight." The private pilot reported that the airspeed indicator was temporarily inoperative and they encountered "...substantial turbulence..." during the instrument approach procedure at Coshocton.

The CFII reported that just prior to "...executing our missed approach procedures, we had a dramatic loss of RPM; felt/sounded like carburetor ice." The private pilot reported that after the power loss "...we switched tanks, confirmed mixture 'full rich' and [carburetor] heat 'on.' Power was at about 1700 RPM, full throttle." When engine power continued to decay, the private pilot selected a field and set the airplane up for the forced landing. He reported that while maneuvering for landing the engine lost power completely. The pilots reported that the CFII took over the flight controls to maneuver to avoid a treeline during the forced landing. The pilots stated that the airplane struck the ground in a slight right wing low attitude, and skidded to a stop.

Both pilots stated that they believed the loss of engine power was due to carburetor ice. A carburetor icing probability chart prepared by the Federal Aviation Administration (FAA) is appended. Postaccident inspection of the aircraft by FAA Air Safety Inspectors revealed no evidence of preimpact mechanical problems and the fuel in both tanks appeared to be free of contamination. The engine was test run under the supervision of FAA Safety Inspectors. They reported that the engine started normally and ran smoothly, with no anomalies noted.