What was found
NR 1 CONNECTING ROD FAILED IN FLT, OFF-AIRPORT LANDING AND SUBSTANTIAL DAMAGE. CONNECTING ROD FAILED SLIGHTLY ABOVE CRANKSHAFT; ROD CAP STILL BOLTED & SAFETIED TO DAMAGED & SEPARATED LOWER PORTION OF CONNECTING ROD. DAMAGE TO CRANKCASE, CRANKSHAFT, & ADDITIONAL INTERNAL ENGINE COMPONENTS SUGGEST A FAILED/ SPUN NR 1 ROD BEARING, RESULTING IN A LOSS OF LUBRICATION TO NR 1 CONNECTING ROD. EXCESSIVE HEAT BUILDUP, AND SUBSEQUENT SEIZURE TO THE CRANKSHAFT JOURNAL AND ROD FAILURE. THE OIL SCREEN MINIMAL CONTAMINATION, INDICATING A SHORT OPERATING TIME BETWEEN PART FAILURE AND ENGINE SHUTDOWN. ENG EXHAUST WAS CLEAN AND THERE WAS NO EVIDENCE OF EXTERNAL OIL LEAKAGE ON THE ENG; REGARDLESS, OIL QUANTITY IN THE ACFT SUMP WAS BELOW (2) QTS. THE LOW OIL QUANTITY, COUPLED WITH THE POWER REQUIRED FOR FLOAT - PLANE OPERATIONS, CONTRIBUTED TO COMPONENT OVERHEAT AND FAILURE.