Flight Details
The helicopter was transporting state employees to a nearby work site. Before departure, the helicopter's doors had been removed. The pilot took off, climbed to about 400 feet mean sea level (MSL), and accelerated to 90 knots. The first minute of flight was routine, and the pilot did not indicate any malfunctions.
Incident Sequence
Suddenly, a loud bang was heard, followed by a slight shudder in the tail rotor pedals. A passenger reported observing pieces of the tail rotor blades flying past the left side of the helicopter. The pilot applied pressure to the tail rotor pedals, but no response was evident. The pilot then performed an autorotation to a landing on rough terrain covered with vegetation.
Post-Accident Examination
The helicopter was recovered and examined. Investigators found no evidence of mechanical problems. The tail rotor blade assembly was not located.
Maintenance Background
Two days before the flight, company maintenance personnel had replaced one of the two tail rotor pitch change links due to excessive wear in its rod end bearing.