The pilot reported that he was performing agricultural spraying operations in the helicopter when the accident happened. He stated that he was making a final "trim" pass along the northern boundary of the field and heading west into the afternoon sun. He said that as he finished his pass, he looked down at the spray boom to insure that the nozzles were shut off and when he looked back up he saw the wires that crossed his path as they contacted the helicopter. The helicopter became uncontrollable and impacted into a field in a nose low attitude. The pilot made no mention of pre-impact difficulties with the helicopter in his statement.