On October 19, 2008, at about 1530 central daylight time, a single-engine Cessna A185F airplane, N93291, was substantially damaged during a forced landing following a reported loss of engine power while executing a missed approach procedure following a practice instrument landing system (ILS) approach at the Brazoria County Airport (KLBX), near Angleton, Texas. The commercial pilot, sole occupant of the airplane, was not injured. The airplane was registered to and operated by a private individual. Visual meteorological conditions prevailed throughout the area for the 14 Code of Federal Regulations Part 91 flight. No flight plan was filed for the local personal flight. The 1976 model airplane was powered by a 300-horsepower fuel injected Continental IO-520D engine, serial number 554473-H. The engine had accumulated a total of 194.6 hours since it was last overhauled on January 24, 2003. The pilot reported that the airplane was recovered from a local paint shop the day prior to the accident. The airplane had been at the paint shop for several weeks while the airplane was completely re-painted. The pilot reported to local authorities that the purpose of the local flight was to flight test some of the features on a newly installed auto pilot system on the airplane. The pilot reported that the engine experienced a partial loss of power when he initiated a practice missed approach procedure from Runway 17. The pilot added that he attempted to regain engine power as he initiated a 180-degree turn to return to the airport when the engine lost total power. The pilot elected to execute the forced landing in an open field. During the forced landing to the open field, the airplane was not able to clear the tall trees on the approach end of the field and the left wing collided with the trees. The airplane came to rest in the upright position and there was no fire. An FAA inspector, who traveled to the accident site reported that the damage to the tail-wheel-equipped airplane consisted of a collapsed right main landing gear strut and the right wing was also damaged. The outboard portions of both wings were also damaged when the wings collided with the top of the trees prior to ground impact. All three propeller blades were bend aft around the engine cowling. None of the blades had any signs of rotational damage and the propeller spinner was undamaged. The pilot reported having accumulated a total of 1,245 hours of which 44 were in the same make and model, with 11 hours in the preceding 90 days. The airplane was transported to a secure location near Lancaster, Texas, for further examination. The damage to the engine was minor and the investigator-in-charge elected to attempt to run the engine. In preparation for the engine run, the propeller was replaced and an external fuel container was attached to the left side fuel system. The engine was run while the engine was still mounted on the airframe. The engine was successfully run for the first seven minutes. A few seconds later, the fuel pressure dropped and the engine stopped running. The airframe was moved back into the hangar where a detailed examination of the fuel system was accomplished. No discrepancies or anomalies were noted with the airframe and engine fuel system. The engine was run a second time at high power settings for over 8 minutes without further anomalies. The investigation concluded that the reason for the reported loss of engine power could not be determined.