On June 22, 2005, approximately 0845 central daylight time, a Garlick Helicopters Inc., OH-58A+ helicopter, N372NS, registered to and operated by Northstar Helicopters, Inc., of Jasper, Texas, collided with high tension wires and impacted the ground while maneuvering during aerial application of pesticides in the vicinity of Graham, Texas. The commercial pilot, sole occupant of the helicopter, was seriously injured. Visual meteorological conditions prevailed throughout the area and a flight plan was not filed for the Title 14 Code of Federal Regulations Part 137 aerial application flight. The local flight originated at 0545 from a nearby private facility. According to the operator, the 10,000-hour pilot had completed spraying a pasture and was trimming the edges when the helicopter struck the wires during a pull-up maneuver. Examination of the helicopter by an FAA inspector, who traveled to the accident site, revealed evidence of tail boom contact with the guide of a high tension string with subsequent in-flight tail boom separation. After the tail boom separated, the helicopter descended uncontrolled to ground impact. The wires were not equipped with fixed aerial obstruction features (orange balls, etc.).