Incident Overview
Minutes after departing, the pilot observed that the engine was not achieving full manifold pressure. Shortly thereafter, the oil pressure dropped to zero. As the engine began to vibrate, the pilot shut it down and executed a forced landing to a field.
Post-Accident Examination
An examination of the airplane disclosed oil covering the engine cowling. The engine's crankshaft seal had been 'blown outward.' Ice was found in the engine crankcase breather line. Additionally, a bend was noted in the breather line near a clamp that had been installed over the breather line vent hole. No other discrepancies were identified with the airplane.
Environmental Conditions
The outside air temperature at the airport around the time of the event was 0 degrees Fahrenheit. The airplane had last been flown one week prior. It was stored in an unheated hangar; however, the engine was preheated using a built-in heater, achieving an oil temperature of 40 degrees Fahrenheit just before engine start.