On August 26, 2015, about 1345 central daylight time, an Air Tractor AT-602, N3026R, collided with the terrain under unknown circumstances in Pine Bluff, Arkansas. The pilot was seriously injured. The aircraft was registered to and operated by Farm Brothers Flyers LLC under the provisions of 14 Code of Federal Regulations Part 137 as an aerial application flight. Visual flight rules conditions prevailed for the flight, which not operated on a flight plan. The local flight originated at 1300 from the operator's private airstrip in Ladd, Arkansas. The pilot reported he finished spraying the rice field and the last thing he remembers is lining up for a trim pass on the south side of the field. He does not have any recollection of the impact. A Federal Aviation Administration inspector who inspected the accident site and the wreckage reported the airplane was traveling at a high rate of speed when it contacted the rice field. The airplane impacted the ground twice prior to coming to rest. The first impact appeared to be in a wings level attitude about 150 yards prior to the main wreckage. Another impact mark was located about 50 yards prior to the main wreckage. The airplane nosed over and slid about 35 yards prior to coming to rest. Flight control continuity was established. The propeller, which was separated from the wreckage, was recovered and the blades were twisted and bent. The left wing spray boom, the propeller and propeller hub were separated from the airplane during the impact sequence. Both wings and the fuselage were substantially damaged. The operator reported there was no mechanical malfunction or failure of the airplane.