Primary finding
Probable cause
The pilot's failure to maintain adequate altitude and physical alertness which resulted in an in-flight collision with the water. Contributing to the accident was the pilot's fatigue.
Investigator assessment
Analysis narrative
The pilot stated that he was on a cross country flight at 1,000 feet mean sea level. About 1 hour 25 minutes into the flight, he recalled the sound of water hitting the helicopter and the next thing he remembered was after the impact. He further reported there was no mechanical failure or malfunction with the helicopter, and the cause of the crash was due to fatigue. The pilot stated that he had three days of restless sleep and no appetite prior to the accident due to stress.
Source record
Factual narrative
The pilot stated that he had lack of appetite and sleep during the previous 3 days which made him fatigued. He awoke about 0400, and departed about 0430, for a cross country flight which was flown between 1,000 and 1,200 feet and 102 knots. About 1 hour 25 minutes into the flight, or at 0555, he recalled the sound of water hitting the helicopter and the next thing he remembers was being very still and quiet. He realized he had crashed, released his restraint, and called his girlfriend via cellular phone for help. A search was initiated and he reported being rescued about 1030, then airlifted to a hospital for treatment. He further reported there was no mechanical failure or malfunction of the helicopter, and the cause of the crash was "...due to fatigue."