Robinson R-44 N300FX accident near Gallatin, Tennessee

Probable cause

The pilot's inadvertent descent into water as a result of the dark night and limited outside visual references.

NTSB analysis

The certificated private pilot was flying his second of two solo night flights for an add-on helicopter rating. He flew the same route as the previous evening but, due to a change from daylight savings time to standard time, he was flying the route an hour later. The end of nautical twilight was about 15 minutes before the accident and the moon was in its crescent phase. According to radar data, which did not include altitude readouts, the helicopter overflew a river leading to a small town, then followed the river, mid-stream, as it turned to the left. The helicopter then flew over a bridge and disappeared into the river on the other side. Examinations of the wreckage revealed no mechanical anomalies. The pilot did not hold an instrument rating and was conducting night operations over water, which likely resulted in spatial disorientation.

Text from the NTSB. Open the NTSB docket for ERA09FA036 for the full record.