On August 29, 2010, at 1428 eastern daylight time, a Cessna 120, N2493N, was destroyed when it impacted terrain following a loss of engine power after takeoff from Knox County Regional Airport (RKD), Rockland, Maine. The certificated private pilot was not injured. Visual meteorological conditions prevailed and no flight plan was filed for the local personal flight conducted under the provisions of Title 14 Code of Federal Regulations Part 91. According to the pilot, during takeoff from runway 31, he noticed the engine “wasn’t producing as much power as it should have been.” The pilot believed he could not safely turn back to the airport and decided to perform a forced landing straight ahead. During the forced landing, the airplane impacted trees before coming to rest on the ground. The pilot reported he fueled the airplane about 10 days prior to the accident, after his last flight in the airplane. At that time, he "topped the fuel tanks" with 100LL aviation fuel. The pilot additionally reported the carburetor heat was "off" during the takeoff. A witness, who was flying an airplane in the traffic pattern at RKD observed the accident airplane depart from runway 31, and "appeared to be having difficulty gaining altitude." As the airplane passed the intersection of runway 21 and 31 it drifted to the northeast side of the runway, "still appearing to be having difficulty gaining altitude." As the airplane continued to the northwest it made a couple of shallow turns eventually turning in a westerly direction at low level. The witness lost sight of the airplane as it descended behind trees to the west of the approach lights for runway 13. The airplane was examined by a Federal Aviation Administration (FAA) inspector after the accident. According to the inspector, the airplane was mostly consumed by a post-crash fire. However, he examined the flight control surfaces and confirmed flight control continuity from the cockpit to the control surfaces. The inspector rotated the engine and confirmed crankshaft, camshaft, and valve train continuity. Both magnetos displayed severe fire damage; however, when the engine was rotated, the impulse coupling of the left magneto was confirmed to be operating. The spark plugs were examined and appeared to be “extremely worn.” Examination of the propeller revealed one blade was bent aft approximately 30 degrees, and the other blade was straight. Neither blade exhibited rotational scoring. The carburetor and magnetos were removed and disassembled for further examination. No pre-impact mechanical anomalies were noted. Additionally, the fuel selector was noted to be in the right tank position. The pilot held a private pilot certificate with a rating for airplane single-engine land. His most recent third-class medical certificate was issued on April 14, 2008. At that time, he reported 181 hours of total flight experience. The recorded weather at RKD, at 1355, included wind from 260 degrees at 9 knots, gusting to 14 knots, 10 miles visibility, clear skies, temperature 30 degrees C, dew point 18 degrees C, and altimeter setting 30.02 inches of mercury. A review of the information found on the FAA Carburetor Icing Probability Chart; and given the atmospheric conditions prevailing during take-off, revealed that the airplane was operating within the "serious icing – glide power" range.