N448JMEurocopter AS 355N · 1997

The pilot picked up the helicopter from a repair facility and while flying home heard a “boom,” felt a vibration in the tail, and performed a precautionary landing to a beach. Postaccident examination of the helicopter revealed that the engine cowling had become unlatched and was subsequently struck by a main rotor blade. The detached cowling then struck the horizontal stabilizer and tail rotor, which resulted in substantial damage. The pilot reported that he did not confirm that the engine cowling latch was properly secured during his preflight inspection. He reported that there were no mechanical malfunctions or failures of the helicopter before the cowling opened and detached.