What happened
During the takeoff for a third touch-and-go landing, the pilot experienced sluggish engine performance followed by a total loss of oil pressure. Because there was insufficient runway remaining to land, the pilot continued to climb and notified the tower of the engine malfunction. Although cleared to land on any available runway, the engine then quit entirely.
The pilot initiated a left turn to return to the airport. While descending, the pilot attempted to correct a nose-down and left wing-low attitude; however, the flight controls became unresponsive prior to the aircraft impacting the water.
The investigation
The aircraft was recovered and the engine was removed for examination. Investigators discovered a hole in the top of the crankcase near the number 4 cylinder. Further inspection revealed that the number 4 cylinder connecting rod had become detached from the crankshaft.
Additionally, the fire sleeves protecting the three oil lines attached to the left and right oil coolers were found to be soaked in oil. During the removal of these sleeves, one line broke due to deterioration. The remaining two lines were also found to be deteriorated. Data tags on each line indicated they were manufactured in April 1972.