What happened
On December 8, 2011, at approximately 15:30 EST, a Curtiss Wright P40M, registration N5813, was performing a local flight from Clermont County Airport (I69) in Batavia, Ohio. The flight, which began around 14:40, was conducted under visual meteorological conditions with 10 miles of visibility and winds from 230 degrees at 7 knots.
While returning to the airport after completing maneuvers in the local area, the pilot reported that the engine shuddered multiple times and the oil pressure dropped to zero. Approximately 20 seconds after the pressure drop, the engine failed completely. During this period, oil and coolant covered the windshield and canopy, significantly restricting the pilot's forward visibility.
The pilot executed a forced landing at I69, but was unable to stop the aircraft on the runway. The airplane exited the end of the runway and struck the airport perimeter fence. The pilot sustained one minor injury, and there were no fatalities. The aircraft sustained substantial damage to the horizontal stabilizer and both wings.
The investigation
Post-accident inspection of the engine revealed a crack in the engine oil cooler located adjacent to a thermostatic bypass valve. The oil cooler was an original component from the World War II era. Investigators found that the crack did not originate from a previously repaired section of the component.