Tarlton Helicopters Bell 206B accident

During the dark night, CFR Part 135 cargo, offshore flight over the Gulf of Mexico, the single-engine helicopter did not reached the destination platform. As of April 2002, the commercial pilot and the helicopter are missing. The pilot is presumed fatal, and the aircraft is presumed destroyed. Search efforts were hampered by weather including 8 to 10 foot seas, wind from 25 to 44 knots, thunderstorms, rain, fog, and visibilities between 0 and 3 miles with a cloud ceiling ranging from 200 to 600 feet. During the multiple air and surface searches, covering in excess of 7,000 square miles, no wreckage or debris was recovered. The 61 year-old pilot had accumulated over 15,000 flight hours. The pilot flew 950.6 hours in the previous calendar year, 298.7 hours in the previous quarter, and 108.4 hours in the current month. The pilot's flight/duty day began at 0800 and he had accumulated 7 flight hours prior to his last communication with dispatch. The helicopter was equipped with fixed floats; however, aside from the pilot's life vest, there was no overwater survival equipment aboard the helicopter. The helicopter was neither equipped nor certified for flight in IMC. A GPS and a telephone were installed in the helicopter. Total airframe time was 17,843.6 hours with 28.5 hours accumulated since the last continuous airworthiness inspection. The meteorological conditions probably existing near the destination platform were: cloud bases near 700 feet, flight visibility 0 in the clouds and near 3 miles below the lowest cloud base, light turbulence below 5,000 feet, and winds southerly at 22 to 29 knots.

Verbatim NTSB analysis and probable cause from the NTSB dataset