On June 11, 1997, approximately 1545 central daylight time, an Air Tractor AT-400, N36538, sustained substantial damage following impact with terrain during initial climb following takeoff from a private agricultural strip near Church Point, Louisiana. The commercial pilot, sole occupant of the airplane, was not injured. The airplane was registered to and operated by Church Point Flyers Inc., Church Point, Louisiana, as a Title 14 CFR Part 137 flight. Visual meteorological conditions prevailed for the local aerial application flight which was originating at the time of the accident. No flight plan had been filed. The pilot reported in his NTSB's Pilot/Operator Aircraft Accident Report (Form 6120.1/2) that he was departing to the north using full power with 2,230 pounds of fertilizer on board. The pilot further reported that: "I started my takeoff roll with 10 degrees [of] flaps and increased [them] to 30 degrees further down the strip. As I got to the end of the strip I had to pull the plane off to clear a large levee, after which it settled back down to the ground." The pilot stated that the airplane landed in a rice field with a "large ditch or canal in it." The airplane's left wing sustained damage to several ribs and the reinforced leading edge skin, and the left main landing gear connecting point to the fuselage was damaged. The pilot stated to the FAA Inspectors, who went to the accident scene, that "as the end of the runway came closer, I felt like I was over gross." The FAA Inspectors reported to the Investigator-In-Charge (IIC) that they were unable to determine the actual weight of the airplane at the time of its takeoff roll. The airplane had a different model engine on it then when it left the factory; no paperwork was located in the airplane for the modification nor the new weight limitations. The pilot further stated that "a small shower was approaching and the air was real calm at the time of [the] takeoff." The IIC interviewed another pilot who was working nearby who stated that "it was getting real hot; you could just see the moisture in the air." The second pilot stated to the IIC that "I was getting real concerned about the lift." The IIC determined that the density altitude was approximately 2,300 feet. An Air Tractor manufacturer's representative reported to the IIC that a normal takeoff in an At-400A is performed with the flaps in the up position. The representative further stated that "takeoffs from short strips with heavy loads should be performed with the flaps set at 10 degrees." The representative reported that "no other takeoff configuration for the flaps is authorized in the operating proceedures."