On August 26, 1997, at 1230 eastern daylight time, a Cessna 188B, N21639, registered to Robertson Crop Dusting Services of South Haven, Michigan, was substantially damaged during a forced landing in a crop field near South Haven, Michigan. The pilot reported that the engine lost all power. The commercial pilot reported no injuries. The 14 CFR Part 137 flight was operating in visual meteorological conditions. No flight plan was on file. The local flight departed about 1210. A post accident investigation found that there was an internal failure of a connecting rod. The engine had a total time in service since the last major overhaul of 1,900 hours. The manufacturers recommendation for overhaul is 1,200 hours. The owner of the airplane said that he was hoping that the engine would last through the spraying season and that he intended to overhaul it during the off season.