On August 28, 1999, at 1430 central daylight time, an Ayers S-2R, N8417V, piloted by a commercial pilot, sustained substantial damage during a forced landing following a loss of engine power while maneuvering near Brooten, Minnesota. Visual meteorological conditions prevailed at the time of the accident. The aerial application flight was operating under the provisions of 14 CFR Part 137 and was not on a flight plan. The pilot, the sole occupant, reported no injuries. The local flight departed Brooten Municipal Airport at 1400. According to the pilot's written statement, after an aerial application run of approximately 30 minutes he departed the spray-run in a climbing right turn when the engine, "...burped once or twice and quit." The pilot reported that the terrain around his position was heavily wooded except for a narrow swamp area in which he elected to land the aircraft. A Federal Aviation Administration (FAA) Inspector from the Minneapolis Flight Standards District Office represented the National Transportation Safety Board during the on-scene portion of the investigation. During the on-scene portion of the investigation, the engine and its components were examined. In a statement provided by the FAA Inspector he reported, "Partial disassembly of the P&W R-1340-AN1 engine disclosed that the blower impeller had failed which would have restricted induction air to the cylinders."