On August 17, 1994, at 0948 central daylight time, a Snow S2C, N9498R, registered to Farmers Air Service, Inc., of Houston, Missouri, and operated by a commercial pilot, experienced a loss of engine power while in cruise flight. During a forced landing the airplane impacted a tree and the terrain near Leslie, Missouri. The airplane sustained substantial damage. The pilot reported no injuries. The 14 CFR Part 91 ferry flight was operating in visual meteorological conditions. No flight plan was on file. The flight departed Pekin, Illinois, with the intended destination of Houston, Missouri, at 0800. The airplane was being repositioned between aerial application jobs. The pilot stated that while in cruise flight the engine lost power and oil covered the windshield and side door windows hampering his visibility. He was unable to see to avoid trees on the approach during a forced landing. Subsequent examination of the airplane engine revealed that the #2 cylinder (head) had separated through a crack at the parting threads between the cylinder head and cylinder barrel. Lubricating oil was released through the open cylinder and valve mechanism into the cooling air flow around the cylinder and cylinder head.