What happened
A flight instructor was acting as pilot-in-command during a cross-country flight in a Cessna aircraft, accompanied by a student pilot and three passengers. Before departure, the instructor noted that the engine oil level was 9 quarts and the oil on the dipstick appeared clean. During the cruise phase of the flight, the low oil pressure warning light began to flicker and the oil pressure decreased. After discussing the situation with the student pilot and observing that other engine gauges remained stable and the engine was running smoothly, the instructor decided to continue the flight.
Approximately 20 minutes later, the engine began making a slight clattering noise, prompting the instructor to divert to a nearby airport. Shortly after this decision, a loud bang occurred and the engine seized. The crew performed a forced landing into a small pasture, during which the aircraft struck a fence and several trees. There were no fatalities reported in the accident.
The investigation
Post-accident inspection of the aircraft showed no oil present on the top of the cowling or the windshield. However, oil was discovered on the bottom of the cowling and left a trail along the bottom of the fuselage. A detailed examination of the engine revealed evidence of an internal catastrophic failure.