On July 17, 2012, about 1100 eastern daylight time, a Cessna 175A airplane, N7003E, conducted a forced landing after a loss of engine power near Shelby, Indiana. The certificated flight instructor (CFI) and the pilot rated passenger were not injured. The airplane sustained substantial damage. The airplane was registered to and operated by a private individual under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed for the flight, which operated without a flight plan. The flight departed the Anderson Municipal Airport (KAID), Anderson, Indiana, and was headed for the Poplar Grove Airport (C77), Poplar Grove, Illinois. According to a statement provided by the CFI, while cruising at 4,500 feet mean sea level, he heard a knocking sound coming from the engine. Engine power was reduced and the pilots began to divert to a nearby airport when they heard a big "clunk" from the engine. Smoke emanated from the engine and filled the cockpit. The CFI performed a forced landing to a bean field. During the landing the airplane nosed over resulting in substantial damage to the vertical stabilizer. Damage was also noted to the engine case and the #3 cylinder counterweight. An examination of the engine found evidence of oil starvation resulting in damage to the engine. The reason for the oil starvation could not be determined.