Summary
On March 3, 2010, at approximately 1435 eastern standard time, a Cessna P210N, registration N4797K, was substantially damaged following a loss of engine power and forced landing near Arcadia, Florida. The commercial pilot received minor injuries, and the passenger was seriously injured. The personal flight operated under 14 CFR Part 91 in visual meteorological conditions without a flight plan. The flight originated from Buckingham, Fort Myers, Florida, about 1400.
Accident Details
According to the pilot, about 25 minutes into the cross-country flight, engine power was lost and manifold pressure dropped to 18 inches. A grinding noise followed, and oil pressure fell to zero. A loud bang occurred, and the engine began running rough. Unable to maintain altitude, the pilot executed an emergency landing in a field. During the landing, the airplane struck a power line pole and came to a stop. A power line separated from the pole, igniting a brush fire. The pilot and passenger evacuated as the airplane became engulfed in flames.
Examination Findings
Post-accident examination by an FAA inspector revealed that the airframe was completely consumed by the post-crash fire. Inspection of flight control components showed no evidence of preimpact mechanical malfunction. The aircraft was removed for further examination of the engine and systems. The pilot reported that all maintenance logbooks were destroyed in the fire.
Engine Examination
The engine and components were sent to Teledyne Continental Motors for examination under NTSB and FAA supervision. The engine displayed heavy fire damage and thermal discoloration. Disassembly yielded two quarts of dark oil containing fragments of connecting rod bolts, bearings, and number 2 crankshaft main bearing pieces. The number 2 main bearings were fragmented and extruded, with mechanical damage. The crankshaft and counterweight assembly had separated, with damage concentrated at the number 2 connecting rod journal forward cheek. The number 1 connecting rod and bearings showed mechanical damage. The number 1 main bearing support was fractured. The camshaft was bent, with damage on several lobes. The oil pump had radial scoring and hard particle passage signatures.
Metallurgical Analysis
A detailed metallurgical examination by the NTSB Materials Laboratory determined that the crankshaft fatigue fracture resulted from bearing wear and bearing shift. Fatigue features on a connecting rod bolt indicated a secondary, low-cycle high-stress fracture. Deposits on the journal surface contained chlorine, suggesting contamination or oil additives. An oil sample tested according to ASTM D445 met manufacturer viscosity specifications.