Hughes 369D crash near Saint Thomas, Saint Thomas, US Virgin Islands

The helicopter was flying at about 50 feet above the water at 15 knots photographing a sailing boat, then climbed to 150 feet and drifted left over the top of the boat. Witnesses reported a loud pop and a puff of black smoke from the engine exhaust, after which the engine noise stopped, the aircraft rolled about 90 degrees onto its left side and descended onto the water. All three on board were killed. Inspection found no evidence of pre-crash mechanical failure or malfunction of the structure, rotor head, rotor blades or main rotor gearbox, and none in the engine or its components. Witnesses saw no components fall from the aircraft beforehand. The published probable cause text is truncated in the source, so no cause is recorded here. NTSB report MIA85FA012. Coordinates are approximate to Saint Thomas.