On July 8, 1999, about 1230 Alaska daylight time, a Bell 206B helicopter, N47122, sustained substantial damage during engine start-up, about 75 miles southwest of Deadhorse, Alaska. The helicopter was being operated as a visual flight rules (VFR) U.S. Government flight by the U.S Department of Interior, Bureau of Land Management, Fairbanks, Alaska, when the accident occurred. The helicopter, provided by Tundra Copters Inc., Fairbanks, Alaska, was utilized on an on-demand 14 CFR Part 135 flight. The certificated commercial pilot, and the three passengers, were not injured. Visual meteorological conditions prevailed. VFR company flight following procedures were in effect. During a telephone conversation with the National Transportation Safety Board (NTSB) investigator-in-charge (IIC), on July 8, 1999, the director of operations for Tundra Copters Inc., reported the pilot loaded his passengers into the helicopter at a remote biological survey site. The pilot then began an engine start, but a main rotor blade tie-down strap was still attached to one of the rotor blades. As the rotor blades began to turn, the strap struck the upper end of the vertical stabilizer, crushing the leading edge in an aft direction. The helicopter's tail boom was deformed and wrinkled, just forward of the tail rotor gear box.