On June 13, 2012, about 1915 Alaska daylight time, a de Havilland DHC-2 airplane, N121KT, sustained substantial damage during a forced landing, following a loss of engine power after takeoff from the Talkeetna Airport (PATK), Talkeetna, Alaska. The certificated commercial pilot, and six passengers were not injured. The airplane was registered to, and operated by Rusts Flying Service, doing business as K2 Aviation, under the provisions of Title 14 Code of Federal regulations Part 135, as a visual flight rules (VFR) sightseeing flight. Visual meteorological conditions prevailed, and company flight following procedures were in effect. The pilot reported that he had departed runway 18, at PATK, on a scenic tour flight, and had reduced power to a cruise climb setting. At approximately 1200 feet above the ground, the engine began to run rough, and lose power. The pilot turned back toward PATK, and performed emergency procedures to restore power. The engine continued to run rough at reduced power, and the pilot could not maintain altitude, followed by a total loss of engine power. He made a forced landing to a sand bar on the Chulitna River. On landing the airplane bounced over logs and ditches, and sustained substantial damage to the horizontal stabilizer, elevators, empennage, and main landing gear. After the aircraft was recovered, a Federal Aviation Administration (FAA) inspector from the Anchorage Flight Standards District Office (FSDO), examined the airplane in Talkeetna, on June 14. The inspector reported that the number two cylinder head had cracks radiating from the spark plug hole throughout the cylinder head, and it had begun to separate from the cylinder base.