Incident Overview
A helicopter was transported to a remote work location with its skid landing gear secured to a transport trailer using four heavy-duty ratchet-type tie-downs. Upon arrival, the pilot and several ground crew members prepared the aircraft for an agricultural application flight.
Preflight Oversight
During the pilot's walk-around inspection prior to the flight, the right rear tie-down was overlooked. The pilot subsequently initiated takeoff with the tie-down still attached to the helicopter.
Accident Sequence
As engine power was applied for takeoff, the helicopter immediately rolled to the right and impacted the terrain. The impact resulted in separation of both main rotor blades at mid-span. The transmission and skid landing gear were partially separated from the airframe.
Damage Assessment
The helicopter sustained substantial damage to the main rotor system, transmission, tail rotor, tail boom, and fuselage. A postaccident examination found no preimpact mechanical anomalies with the helicopter, indicating that the aircraft was in normal operating condition prior to the event.