On August 22, 1994, at 1933 central daylight time, a Grumman G- 164A, operated by Benoit Aerial Spraying of Kankakee, Illinois, as an agricultural aircraft, impacted powerlines 2 miles east of Clifton, Illinois, during aerial application and was destroyed. The commercially certificated pilot received minor injuries, egressed the airplane without assistance, the on board chemicals were spilled, and a post crash fire occurred. Visual meteorological conditions existed at the time of the accident and no flight plan was filed. The flight operated under 14 CFR Part 137 and had originated from a private strip near Kankakee, Illinois. The pilot stated that he contacted the known but unmarked powerlines during an application turn. He did not indicate, nor were any pre-impact mechanical discrepancies noted during the investigation.