Engine Failure and Ditching Following Loss of Oil Pressure (N55653)

Incident Summary

The pilot of a single-engine aircraft reported that the engine became sluggish during the takeoff for a third touch-and-go landing, followed by a total loss of oil pressure. With insufficient runway remaining to land, the pilot continued to climb and advised the tower of the engine malfunction. The pilot was cleared to land on any runway, but the engine then quit. The pilot initiated a left turn to return to the airport. While descending, the pilot attempted to correct a nose-low and left-wing-low attitude before impact with the water but stated that the flight controls were unresponsive.

Recovery and Examination

The aircraft was recovered, and the engine was removed for examination. Examination of the engine revealed a hole in the top of the crankcase near the No. 4 cylinder. The No. 4 cylinder connecting rod was not attached to the crankshaft. The fire sleeves protecting the three oil lines attached to the left and right oil coolers were oil-soaked. During removal of the fire sleeves, one line broke due to deterioration. The two other lines were examined and found to be deteriorated. The data tags attached to each line indicated that they were manufactured in April 1972.