On July 21, 2007, about 1700 eastern daylight time, an amateur built Durgin Junior Ace, N9778N, registered to and operated by a private individual, crashed into a wooded area approximately .13 nautical mile east-southeast of the Charles A. Chase Jr. Memorial Field Airport (44B), Dover-Foxcroft, Maine. Visual meteorological conditions prevailed and no flight plan was filed for the 14 CFR Part 91 personal, local flight. The airplane was substantially damaged and the private-rated pilot, the sole occupant, sustained minor injuries. The flight originated about 1615, from 44B. The pilot stated that the airplane had 6 gallons of auto fuel on-board when the flight departed. After takeoff, he flew over Dover-Foxcroft, then returned to 44B, where he performed 2 full-stop taxi back landings. The third takeoff was performed from runway 27, and after takeoff, the flight remained in the traffic pattern. He turned crosswind, then onto the downwind leg, where he reduced engine power to 1,700-1,800 rpm. He had an extended downwind leg, turned onto base then final, where the engine experienced a loss of power. The pilot further reported that the next thing he recalled was colliding with trees, and that 1 wing may have stalled. After coming to rest, he secured the airplane, exited it, and walked about 1/2 mile for assistance. Examination of the accident site by an FAA inspector revealed a portion of the left wing remained suspended in a tree. Another tree located approximately 30 feet away was contacted; the airplane came to rest in a nose-low attitude located at 45 degrees 10.681 minutes North latitude and 069 degrees 14.149 minutes West longitude, or approximately 103.3 degrees magnetic and 790 feet from the approach end of runway 27. The wreckage was recovered for further examination. Examination of the airframe and engine was performed by an FAA airworthiness inspector following recovery of the airplane. The examination of the airframe revealed no evidence of preimpact failure or malfunction of the flight controls. Examination of the engine revealed crankshaft, camshaft, and valve train continuity. The magnetos sparked normally during hand rotation of the engine, and the spark plugs looked normal. The fuel filters were clean and free of contamination. A minimal amount of fuel was noted in the airplane; the amount was not quantified.