THE DTSB
The DTSB determines the Probable Cause of this accident to be Pilot Error, in that the accident pilot elected to fly a very low level, below terrain, high speed flight path for the purposes of giving a thrilling ride, on a course that he had previously flown many times successfully. The accident pilot died from “expectation bias” in that since he had already successfully accomplished this same route many times before, he expected it to still be the same. The accident pilot struck a recently installed recreational “slack line” which stretched from one terrain peak, across a valley to another peak. The collision with the line separated the main rotor from the helicopter. The four helicopter occupants fell to their death from about 600 feet above the underlying valley base terrain elevation. The slack line installers were recreational users and had followed all BLM and FAA regulations concerning the installation of the line as well as proper public NOTICE. The obstruction information was readily available via FAA NOTAM and numerous other flight planning vendors that clearly marked it’s location and elevation. The published Lat/Long definition of the obstruction location was accurate to within 100 feet of the intersection of the slack line and the dirt road beneath it, a fix define as a point by knowing that aircraft would visually follow the road when flying through this area in either direction. The accident pilot did not receive an FAA briefing, and did not notice the new obstruction clearly marked on his intended route. The Probable Cause of this accident is the obvious lack of attention given by the accident pilot to detail required for the proposed low level, thrill based intended flight.