On August 11, 1999, at 0950 central daylight time (cdt), a Rockwell S-2R Thrush, N4923X, piloted by a commercial pilot, was substantially damaged when it struck a power line during a pull-up maneuver at the end of a spraying swath run. Visual meteorological conditions prevailed at the time of the accident. The 14 CFR Part 137 aerial application flight was not operating on a flight plan. The pilot reported no injuries. The flight departed Garden City, Kansas, at 0900 cdt. The pilot said, "I was on my third swath run from the north side of the field heading west, when I misjudged my initial point of pull up and contacted the top wire between two poles with the [airplanes'] right main [landing] gear. There was a big jolt, and I felt the plane begin to slow down, so I proceeded to lower the nose of the aircraft to maintain my airspeed and hopefully break the wire. Approximately 300 yards west of the power line it finally broke." According to the Federal Aviation Administration Principal Maintenance Inspector who examined N4923X and the power line, the pilot said he did not see the wire in time to avoid striking it. The poles suspending the wires were about 1/4 mile apart.