The pilot reported that the flight was normal until the airplane was established on final approach to runway 27 (2,509 feet by 50 feet, turf) at which point the airplane yawed slightly to the right. The pilot attempted a go-around about 100 feet above ground level, but there was a lack of engine power from the right engine. The pilot arrested the descent with power from the left engine, but the airplane impacted terrain at midfield and to the right of runway 27. The airplane sustained substantial damage, which included wing spar damage and a bent fuselage aft of the cabin. Inspection of the right engine by the Federal Aviation Administration was limited to engine compression, which was confirmed.