On January 12, 2002, about 1120 eastern standard time, a Piper PA-28, N6315R, was substantially damaged while executing a forced landing near the Nantucket Memorial Airport (ACK), Nantucket, Massachusetts. The certificated private pilot was not injured. Visual meteorological conditions prevailed for the personal flight that departed Barnstable Muni-Boardman/Polando Field (HYA), Hyannis, Massachusetts, destined for Nantucket. No flight plan was filed, and the flight was conducted under 14 CFR Part 91. According to the pilot, he departed Hyannis and proceeded to Nantucket. The departure, climb, and en route portions were "uneventful." Once in the terminal area, the pilot was cleared to land on runway 30, so he initiated a descent to 1,000 feet agl. After entering a right downwind, the pilot reduced engine power to 1,500 to 1,700 rpm. He set the mixture control to full rich, and selected the fuel pump and carburetor heat to "ON." On "base," the pilot noticed he was approximately 200 feet low. He increased power to maintain altitude, but the engine did not respond. The pilot checked the mixture control, fuel selector, fuel pump switch, and magneto switches, but did not identify any configuration problems. He then selected the carburetor heat to "OFF" and set the throttle to full open. The engine still did not respond. Unable to make the airport, the pilot identified an open field, and selected full flaps. The airplane touched down, bounced once, touch down again, and then struck a tree with the left wing before coming to a stop. According to a Federal Aviation Administration inspector, an engine run was performed after the accident. No fuel was added, and each tank had approximately 15 gallons of fuel at the time of the run. During the run, the engine ran "normally," but the idle speed was set between 450 and 500 rpm, instead of the recommended 750 rpm. The inspector added that with carburetor heat "ON" and the throttle in the idle position, the engine "almost quit." The pilot commented to the inspector that he felt the engine was idling lower than normal prior to the flight. A weather observation taken at the airport 33 minutes before the accident, recorded the wind as 290 degrees at 18 knots, visibility 10 miles, clear skies, temperature 45 degrees Fahrenheit, dew point 27 degrees Fahrenheit, and an altimeter setting of 29.89 Hg. According to the FAA publication, "Tips On Winter Flying," the accident weather conditions were conducive for serious icing with glide power. In addition, the publication stated that, "It is recommended that carburetor heat be applied before reducing power...."