Pilot/Owner Reported That During Straight And Level Flight, He Felt A “Shudder” And Heard A “Thump” And The Airplane’s Engine Over Sped Analysis: The pilot/owner reported that during straight and level flight, he felt a “shudder” and heard a “thump” and the airplane’s engine over sped. He executed a forced landing to a field, but the airplane’s right main landing gear separated from the airplane. The airplane came to rest on the remaining landing gear and the right wing. Postaccident examination revealed that the airplane’s pusher propeller had separated from the engine. During the separation, the propeller struck the left wing, tearing the fabric covering and substantially damaging internal structure.