On March 28, 1998, approximately 1530 central standard time, a Grumman G-164 agricultural airplane, N617Y, impacted terrain during a forced landing following an in-flight collision with trees while maneuvering near St. Joseph, Louisiana. The airplane, which was registered to and operated by the pilot, was destroyed. The commercial pilot, the sole occupant, sustained serious injuries. No flight plan was filed and visual meteorological conditions prevailed for the Title 14 CFR Part 137 local aerial application flight. The pilot reported that the airplane performed "normally" during the first three flights of the day. Prior to the fourth flight, he "removed the side windows of the cockpit." While completing the first pass of the fourth flight, the pilot "noticed the plane did not perform as it had previously." As he turned the airplane to begin the second pass, it "began to settle into the trees" bordering the field being sprayed. "While in the trees," the pilot advanced the propeller and throttle controls and attempted to dump his load of herbicide; however, he "was hitting [the] spray handle instead of [the] dump handle." Upon reaching the edge of the trees, the pilot "nosed the aircraft over to land in a small field before hitting the wire across the road." As he flared to land, the airplane "hit the embankment next to the road." The airplane "flipped across the road," came to a stop in the inverted position, and began to burn. The post-crash fire consumed the fuselage, empennage, and the upper and lower right wings of the biplane. According to FAA records, when the pilot's most recent medical certificate was issued on July 31, 1997, he reported that he had accumulated 15,300 total flight hours of which 300 hours were in the last 6 months.