What happened
The incident occurred during a banner tow flight operation. Approximately thirty minutes into the mission, the aircraft's engine began to run roughly. At the time of the malfunction, the airplane was positioned at an altitude of 300 feet above the ocean, adjacent to a public beach. Due to the loss of power and the inability to maintain altitude, the pilot made the decision to ditch the aircraft in the water rather than risk landing on the crowded shoreline.
The investigation
Following the accident, a subsequent examination of the engine was conducted to determine the cause of the failure. The inspection revealed that the exhaust valve for number four cylinder had broken at the piston end. Records indicated that the engine had accumulated 1939 hours since its last overhaul.
Findings
The mechanical failure of the exhaust valve in the number four cylinder was the primary factor leading to the loss of power. The aircraft involved was a Piper PA-23 Aztec. The flight phase was identified as banner tow. No fatalities or injuries were reported in this account, though the specific count is not explicitly detailed beyond the ditching event.
Safety message
The incident highlights the risks associated with mechanical failures during low-altitude operations over water near populated areas. Proper maintenance and monitoring of engine hours since overhaul are critical for preventing such failures.