NTSB Factual Report

On March 15, 2011, about 1330 eastern daylight time, a Cessna 182P, N430ML, experienced a total loss of engine power during a descent near Alachua, Florida and the pilot subsequently made a forced landing to a field. The certificated private pilot was not injured. The airplane was operated by a private individual under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed and no flight plan was filed for the flight destined for Cannon Creek Airpark (15FL), Lake City, Florida. The flight departed Leesburg International Airport (LEE), Leesburg, Florida, about 1200.

According to the pilot, he banked the airplane into a descending left turn in order to set up a visual approach to the destination runway when the engine lost partial power. The pilot verified that the mixture was full and moved the fuel selector from the right tank position to the left tank position, and then to the both position but was unable to restore full engine power. He increased the throttle in an attempt to restore engine power, but it then lost total power. Subsequently, the pilot made a forced landing into a field, the airplane nosed over, and came to rest inverted resulting in substantial damage. According to maps, the destination airport measured about 19 miles from the accident site.

A post accident examination of the wreckage revealed that there was fuel noted in both fuel tanks. Examination of the engine by a Federal Aviation Administration (FAA) inspector revealed that the engine would partially rotate by hand and exhibited resistance during the rotation.

According to FAA records, the pilot held a private pilot certificate for airplane single-engine land, glider, and a rating for instrument airplane. His most recent third-class medical certificate was issued in January 2011. The pilot reported 2,000 hours of total flight time, of which, 750 hours were in the same make and model as the accident airplane.

According to FAA records, the airplane was manufactured in 1974. It was an all metal, high-wing, single-engine, cantilever monoplane with fixed tricycle landing gear. The airplane was equipped with a 300-horsepower, Continental Motors IO-550 series engine. The most recent annual inspection was performed on March 1, 2010, and at the time the tachometer indicated 1492.9 hours. At the time of the accident the tachometer indicated 1504.4 hours.

The engine was installed new on the airplane in July 2001 by a certificated repair station. At the most recent annual inspection, the engine had accumulated 739.2 hours of total time in service. At the time of the accident, the engine had accumulated 750.7 hours of total time in service and 217.4 hours since all six cylinders were replaced. The maintenance records indicated that the oil was changed during the most recent annual inspection and at regular intervals in the past.

The engine was further examined at the manufacturing facility in Mobile, Alabama, on August 26, 2011. During the examination, 14 quarts of oil was drained from the engine. The starter adapter drive was removed and wear was noted on drive gear teeth. The oil pump assembly was removed, disassembled, and scoring on the pump housing and gears was noted. In addition, metal fragments were present inside the pump housing. The oil pressure relief valve exhibited damage to the valve face. Both magnetos were removed. The left magneto drive gear did not rotate freely and upon closer inspection, a broken gear tooth was wedged between the idler gear and magneto gear. Once the tooth was removed, the left magneto rotated freely.

The oil sump was removed and revealed that the No. 1 exhaust lifter seized in the lifter boss. Spalling was present on all lifter faces. Excessive wear was noted on all camshaft lobes and all of the lobes exhibited spalled surfaces. The cylinder deck nuts and through bolts were checked for torque and break away torque. Two cylinder deck nuts and one through bolt on the No. 3 cylinder were found to be below the minimum torque. No other anomalies were discovered with the other cylinder nuts.

All cylinders were removed and the cylinder bores exhibited normal wear with no scoring present. All piston domes exhibited normal wear and indications of multiple valve strikes. The piston rings displayed normal wear. All valves exhibited hammered valve faces, the valve key retainer slots had sharp raised edges, and the valve tips exhibited mushrooming. The crankcase halves were separated with no sign of fretting or deformation. The camshaft gear was missing nine teeth in addition to one partially damaged tooth. The crankshaft gear was missing four consecutive teeth and one tooth was missing from another location on the gear.

The valve lifters were tested for bleed down and were found to be within manufacturer specifications. No anomalies were noted with the cylinder valves to guide measurements. The magnetos were tested with the original engine harness and produced spark on all towers. The fuel pump was pressure tested on a factory calibrated test bench which indicated the fuel pressure setting was higher than the manufacturers recommended specifications. The fuel metering and throttle body were pressure tested on a factory calibrated test bench and found to be flowing on the low side of the manufactures recommended specifications. The fuel manifold valve was tested on a factory calibrated test bench and found to be flowing below the manufactures recommended specifications. Further examination of the fuel system found contaminants in the fuel metering unit screen. The oil filter was opened and contained metal particles consistent with steel and aluminum.

The camshaft gear, crankshaft gear, an exhaust valve, lifter, and debris recovered from the oil sump were submitted to the Continental Motors Engineering Department for metallurgical evaluation under the supervision of an FAA inspector. Both the camshaft gear and crankshaft gear had missing teeth and the fracture surfaces were damaged due to post separation contact. The camshaft gear, crankshaft gear, an exhaust valve, and lifter met the material property requirements. The debris from the oil sump was identified as nitrided gear material and lifter fragments.

According to the owner and the engine maintenance log, no documented propeller strikes had occurred since the engine was installed on the airframe.

NTSB Probable Cause

A loss of engine power due to the failure of the camshaft gear teeth and crankshaft gear teeth for undetermined reasons.