N802KA

The pilot reported that he intended to spray an agricultural field and was maneuvering in preparation for his first pass when the helicopter lost engine power. The pilot subsequently accomplished a forced landing to an open field. During the landing sequence, the helicopter’s main rotor blades flexed down and made contact with the tailboom, which resulted in substantial damage to the tailboom assembly. The pilot reported that after the landing he discovered the fuel selector valve in the off position. He reported that he had turned the fuel selector valve to the off position to drain the fuel sump during the preflight; however, failed to re-open the valve after the preflight and prior to takeoff.