What happened
During cruise flight alongside another aircraft at an unspecified altitude, the pilot observed a gradual decrease in oil pressure. Shortly thereafter, the engine ceased functioning. Despite the mechanical failure, the oil temperature, cylinder temperature, and exhaust gas temperature remained within normal operational ranges until the moment of impact. The engine stopped rotating prior to the aircraft ditching into approximately 700 feet of water.
The investigation
The investigation focused on the sequence of events leading to the loss of power. The pilot's statement indicated that the oil pressure drop was the primary indicator of impending failure, even though other temperature gauges remained stable. The engine stopped rotating before the aircraft entered the water, confirming a complete loss of propulsion prior to ditching.
Findings
The critical factor in this incident was the loss of oil pressure, which led directly to engine failure. The fact that temperatures remained normal suggests the failure may have been related to lubrication rather than overheating. The aircraft was lost in deep water, making recovery and detailed mechanical inspection impossible.
Safety message
Pilots should monitor oil pressure closely during cruise. A drop in pressure can indicate imminent engine failure even if other parameters appear normal. Immediate action is required when oil pressure decreases unexpectedly.