On January 9, 2011, at 1315 Pacific standard time, a Piper PA-22-150, N5850D, sustained substantial damage following a loss of engine power and subsequent forced landing near the Lopez Island Airport (S31), Lopez, Washington. The certified flight instructor and student pilot receiving instruction were not injured. The airplane was registered to the student pilot, and operated as an instructional flight under the provisions of 14 Code of Federal Regulations (CFR) Part 91, when the accident occurred. Visual meteorological conditions (VMC) prevailed in the area during the time frame of the accident. No flight plan was filed for the local instructional flight. In a written statement, the flight instructor reported that shortly after takeoff, approximately 500 feet above ground level, the airplane began to lose engine power. The instructor lowered the airplane’s nose and began a turn towards open terrain. Approximately 90 degrees into the turn, the engine quit developing power. The pilots attempted to resolve the problem by applying carburetor heat, changing throttle positions, and switching fuel tanks; however, they were unsuccessful. The instructor maneuvered the airplane to a nearby field and initiated an emergency off airport forced landing. During the landing roll, the airplane collided with thick vegetation and came to rest adjacent to the field's perimeter fence. The airplane sustained substantial damage to the fuselage and forward undercarriage. Postaccident examination of the airframe and engine revealed no preaccident mechanical malfunctions or failures that would have precluded engine operations. A detailed engine examination report is contained in the public docket for this case file. The airplane was operating in conditions potentially conducive to carburetor icing at the time of the accident. The carburetor icing probability chart included in Federal Aviation Administration Special Airworthiness Information Bulletin No. CE-09-35, Carburetor Icing Prevention, indicated that there was a risk of carburetor ice accumulation; however, it was not determined if carburetor ice contributed to the loss of engine power. The reported weather was, in part, temperature 2 degrees Celsius, dew point minus 6 degrees Celsius and a relative humidity of 57 percent.