NTSB Factual Report

On December 23, 2003, approximately 1500 central standard time, a Cessna 172K, single-engine airplane, N111TK, registered to and operated by a private individual, was substantially damaged following a loss of engine power approximately 10 miles south of Lake Charles, Louisiana. The commercial pilot and his passenger were not injured. Visual meteorological conditions prevailed and a flight plan was not filed for the 14 Code of Federal Regulations Part 91 personal flight. The flight originated from Stennis International Airport (HSA), near Bay Lou, Mississippi, about 1430, and was destined for the Houma-Terrebonne Airport (HUM), near Houma, Louisiana.

According to the Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1/2), the 1,200-hour pilot reported that he was flying at 1,500 msl, when he noticed "a gradual decrease in engine power." He switched the fuel tanks, checked the magnetos, applied carburetor heat, and checked the primer. The pilot stated that he checked the primary engine instruments and "all indicated normal operation." The pilot further reported that he "pumped the throttle, which appeared to make a positive difference." Subseqently, the airplane experienced a total loss of engine power, and the pilot initiated a forced landing to a saturated field. Upon touchdown, the nose wheel sunk into the mud. the airplane nosed over, and came to rest inverted.

Examination of the airplane by a Federal Aviation Administration (FAA) inspector, who responded to the accident site, revealed structural damage to the engine firewall, tail section, and the upper wing. According to records provided by the FAA, the engine was last overhauled on April 20, 2003, and accumulated 304.2 hours since the overhaul. The engine total time was 6,214.2 hours since new.

An examination and teardown of the engine was accomplished under the supervision of the FAA at a salvage yard located at Bogalusa Airport, Bogalusa, Louisiana, on February 12, 2004. During the examination, a large hole in the engine case was present under the #2 cylinder, and several small breaks in the were present on the top left of the case near the #2 and #4 cylinders. The #1 cylinder spark plug seat was cracked and showed evidence of impact damage was noted. A circular impression, corresponding to the end of the #1piston rod, was observed on the inside of the #1 spark plug seat. The #1 piston head was found totally disintegrated. Fragments of metal were found throughout the case. Exhaust and intake valves did not appear to be damaged.

NTSB Probable Cause

The disintegration of the piston, which resulted in the catastrophic failure of the engine. A contributing factor was the lack of suitable terrain for the forced landing.