On September 19, 1999, at 0920 central daylight time, a Grumman-Schweizer G-164B, N6736Q, collided with a tree and the ground during a forced landing following a loss of engine power in Enterprise, Alabama. The airplane was operated by the commercial pilot under the provisions of Title 14 CFR Part 137 and visual flight rules. Visual meteorological conditions prevailed at the time of the accident and no flight plan was filed for the local agricultural flight. The pilot received minor injuries and the airplane was destroyed by the subsequent post-crash fire. The flight departed Enterprise, Alabama, at approximately 0910. According to the pilot, he departed Enterprise Airport with a full load of chemicals for aerial application to a nearby cotton field. Shortly after takeoff, the engine began to surge. He adjusted the propeller lever to "high" and turned the fuel boost pump "on", but did not adjust the power lever because torque and exhaust gas temperature appeared normal. He elected to return to the airport and while on short final he observed another airplane pass beneath him. He felt he could not land ahead of or behind the other airplane without endangering both aircraft. His airplane, although surging, had been producing sufficient power therefore, he executed a left 360 degree turn for spacing. When the turn was nearly complete, the engine lost all power and he maneuvered for an open field. He collided with a tree and then the ground. The airplane subsequently caught fire but he was able to exit the airplane with only minor injuries. According to the FAA, examination of the wreckage revealed that the wings, empennage, and fuselage were destroyed almost beyond recognition. The only recognizable portion of the engine was the power section and the entire turbine section was destroyed. A fuel sample of the Jet-A fuel used in the airplane showed no visible evidence of contamination. The airplane and engine were consumed by fire.