On October 1, 2011, about 1255 mountain daylight time, a Robinson Helicopter, R66, N266CY, was substantially damaged during an in-flight breakup while in cruise flight near Philip, South Dakota. The private pilot, the sole occupant, was fatally injured. The helicopter was registered to and operated by P P & J LLC., of Gillette, Wyoming. Visual meteorological conditions prevailed and a flight plan was not filed for the 14 Code of Federal Regulations Part 91 personal flight. The cross-country flight originated from the Gillette-Campbell County Airport (GCC), around 1105 en route to Winner Regional Airport (ICR), Winner, South Dakota.

A friend of the pilot was at GCC when the pilot was preparing for the flight. The friend reported that the pilot appeared to be in good health and was excited about the flight. He further reported that the pilot had “topped off” the helicopter with fuel before departure. Approximately an hour and a half later the pilot called the friend during the flight. The pilot reported that he was between Wall, South Dakota, and Philip, South Dakota, and inquired if the Philip Airport (PHP), had jet fuel available. The friend called the pilot back a few minutes later to say PHP did not have jet fuel. The friend stated that the pilot did not report any anomalies with the helicopter during either conversation.

An eyewitness located approximately 2 miles northwest of the accident site, observed the helicopter flying from west to east, along a river, at approximately 1,000 feet above ground level (AGL). The eyewitness reported that he heard nothing abnormal as the helicopter flew past him. He then observed the helicopter make a turn to the left before it flew out of view behind trees. About 20-30 seconds later, he heard a noise that he described as sounding like an “exploding propane tank.”

The helicopter wreckage and debris came to rest on rolling ranch land and was spread out over an area approximately 1,520 feet long by 600 feet wide. The main rotor head, with attached blades, came to rest 513 feet from the main wreckage. The main wreckage consisting of the fuselage, engine, and tail rotor assembly, had sustained substantial thermal damage from a post crash fire.

At 1255, the automated weather observing system at PHP, located 3 nautical miles northeast from the site of the accident, reported wind from 150 degrees at 6 knots, 10 statute miles visibility, clear of clouds, temperature 84 degrees Fahrenheit, dew point 39 degrees Fahrenheit, and a barometric pressure setting of 30.00 inches of Mercury.