CHI94LA100

The student solo pilot was on the third leg of a VFR cross country after a refueling stop. The nearest weather observation facility reported temperature as 51 degrees f and dew point as 23 degrees f. the pilot reported having experienced carburetor ice indications on the earlier legs. After experiencing a slight drop in engine RPM, carburetor heat was applied by the pilot, the engine continued to run rough and carburetor heat was turned off. Winds were estimated at 12 gusting to 20 knots and the pilot stated the airplane was becoming hard to control. The pilot elected to perform a precautionary landing into an unprepared field. On final approach, carburetor heat was applied again, but full power was not regained. The airplane struck trees at the end of the field.

On March 10, 1994, at 1515 hours central standard time, a Cessna 152, N93679, operated as a training aircraft by Central Missouri State University of Warrensburg, Missouri, was destroyed in the vicinity of Eugene, Missouri, during an off airport precautionary landing. The solo student pilot sustained minor injuries. No flight plan was filed. The flight operated under 14 CFR Part 91, as a student solo cross country and originated from Rolla National Airport, Vichy, Missouri, approximately 1445 hours. The 18 year old student pilot was endorsed for the solo cross country flight. Her most recent experience was on 6 March 1994.

Visual Meteorolgical Conditions existed, with winds of 260 at 12 knots gusting to 20 knots. A weather briefing was obtained prior to the original departure from Skyhaven Airport, Warrensburg, Missouri, with VMC forecast for the route of flight.

The pilot reported experiencing indications of carburetor icing during the earlier legs of the flight. After noting a drop in engine rpm, she applied carburetor heat, the engine continued to run rough, and carburetor heat was turned off. The pilot elected to perform a precautionary landing in an unprepared field. On final approach, carburetor heat was again applied, full power was not regained, and the airplane contacted trees at the end of the landing field and came to rest upright. The propeller was broken off and the wing spars were broken at the fuselage attaching points. The engine remained attached to the wreckage.

Temperature at Columbia, Missouri (COU), located 40 nautical miles northeast of the accident site, at 1550 central standard time was 51 degrees F and the dew point was 23 degrees F. The elevation of Columbia is 889' MSL. The approximate elevation of the accident site is 900' MSL. Cruise altitude for the flight was between 3500' MSL and 4500' MSL.

Post accident inspection revealed a clear blue liquid present in both tanks, with no visible particulates or water. No fuel system anomolies were detected. The engine was removed to a hangar, placed on an engine stand and operated. Differential compression varied from 80/72 to 80/76 in the four cylinders. Static RPM was normal. Both magnetos operated, and magneto checks were normal. The spark plugs were clean. Carburetor heat application resulted in a drop of rpm. Rapid acceleration resulted in a slight hesitation in RPM increase. The carburetor had a one piece venturi and some dark, smoky residue was visible.

Upon disassembly, the accelerator pump fuel jet was found loose in the carburetor body. No other discrepancies were discovered.