On July 7, 2007, about 1916 Pacific daylight time, a WSK PZL Mielec, M-18A (a.k.a. "Dromader") single-engine air tanker (SEAT) airplane, N92043, experienced a total loss of engine power while maneuvering about 20 miles northwest of Burns, Oregon. The airplane was substantially damaged during the pilot's forced landing in a rough, vegetation-covered, open field. The airline transport pilot sustained minor injuries. During the accident flight, the SEAT was under the operational control of the U.S. Department of Agriculture Forest Service. The Forest Service operated the airplane under a "call-when-needed" contract with New Frontier Aviation, Fort Benton, Montana. Visual meteorological conditions prevailed at the time of the public-use fire suppression flight, and a company flight plan had been filed. The airplane was operated with a restricted category Federal Aviation Administration (FAA) airworthiness certificate under the provisions of 14 CFR Part 91. The purpose of the flight was for the pilot to disperse 500 gallons of fire retardant chemical on the Egley Complex Fire in the Malheur National Forest, near Burns. The flight originated from Burns about 1903. The airplane, identified by the Forest Service as T-464, was ferried from Fort Benton to Caldwell, Idaho, where it refueled. The airplane was ferried from Caldwell to Burns and it performed two retardant drops on the Egley fire. After the two retardant drops, the airplane returned to Burns for fuel and retardant. The airplane departed Burns with full fuel on a third retardant drop, made the drop, and returned to Burns for a reload of retardant. The pilot departed Burns at 1903 on his fourth retardant drop. At 1916, while overflying the intended retardant drop zone at 1,500 feet above ground level, the engine lost power and stopped operating. The pilot attempted to restart the engine, but he was not successful. He dumped the retardant load, made an emergency radio call, and attempted a forced landing to a field. The airplane touched down, skidded approximately 100 feet, and came to rest in an upright attitude. At the time of the accident, the airplane flew approximately 1 hour prior to the loss of engine power, utilizing a known fuel burn rate of approximately 55 gallons per hour. The fuel capacity for the airplane was approximately 195 gallons. Examination of the airplane showed that the main and tail landing gears were separated from the airframe. Both wings, horizontal stabilizers, and respective flight control surfaces exhibited punctured holes and separated sections. The propeller blades were observed to be in the feathered position. During the recovery of the airplane from the field, a 3 feet in diameter and 3 feet in depth fuel stain was noted on the terrain directly beneath the airplane fuselage. On August 8, 2007, the airplane's fuel system was examined. Disassembly of the fuel system from the fuel tanks to the engine did not reveal any anomalies that would have precluded normal operation prior to the impact with terrain. On October 16, 2007, the Honeywell Model TPE331-11U-611G (serial number P-44127) engine was examined under the cognizance of the National Transportation Safety Board and the Forest Service. The engine was visually inspected, borescoped, and rotational continuity was established. The engine was then staged and run in a test cell. The engine started and ran without incident. During the test cell run, the engine exceeded the 1,000 shaft horsepower rating and was free of surge and detrimental effects during transient power demands. No pre-existing conditions that would have precluded normal engine operation were noted.