On June 12, 2008, approximately 1400 central daylight time, a Cessna A188B single-engine agricultural airplane, N9639G, sustained substantial damage when it impact terrain during a forced landing following a loss of engine power near Lyons, Kansas. The airline transport pilot, who was the sole occupant, was not injured. The airplane was registered to Ellinwood Flying Service, Inc., Ellinwood, Kansas, and operated by Rice County Aerial Sprayers, Lyons, Kansas. Visual meteorological conditions prevailed, and a flight plan was not filed for the Title 14 Code of Federal Regulations Part 137 aerial application flight. The local flight was originating at the time of the accident. According to the pilot, on May 26, 2008, he experienced an engine problem during an attempted aerial application flight, and landed successfully in an open field near the Lyons airport. After maintenance was performed which included new spark plugs, and checking the fuel and oil systems; the airplane underwent several engine test runs and a couple of test flights with no problems noted. On the day of the accident, the airplane was loaded with approximately 150 gallons of chemical. After takeoff, the pilot turned the airplane in a direction opposite of his intended destination in order to over fly the airport in case of an emergency. During the initial takeoff climb, the engine was running okay and no problems were noted. Approximately 1 to 1.5 miles from the airport, the engine "pulled down," and the pilot could not maintain altitude. The pilot stated, "I am now sure the engine was trying to seize up and I was again forced to land." The pilot elected to perform a forced landing to a field. During the forced landing, the airplane impacted a dirt embankment, went onto its nose, and came to rest upright. In 2002, the Continental IO-520-D engine underwent a major overhaul. At the time of the accident, the engine had accumulated approximately 600 hours since major overhaul. The engine underwent its most recent 100-hour inspection on January 15, 2008. Examination of the engine by a Federal Aviation Administration airworthiness inspector revealed no anomalies. The oil filter and oil screens were clear of debris. The reason for the loss of engine power was not determined.