On May 5, 1995, at 2315 eastern standard time, a Piper PA-23-160, N4300Y, collided with terrain during an emergency landing at the Mark Anton Airport, in Dayton, Tennessee. The commercial pilot had serious injuries, his passenger was uninjured. The aircraft was destroyed by the impact forces and fire. The aircraft was operated under the provisions of 14 CFR Part 91 by Spirit Aviation, Inc., of Bunnell, Florida. Visual meteorological conditions existed at the time of the accident, and an instrument flight rules flight plan was filed for the personal flight to Chamblee, Georgia. The flight originated from Louisville, Kentucky, at 2140 on the same day. The pilot reported that he was in cruise flight when the left engine began to lose oil pressure. He requested assistance from Air Traffic Control, and received vectors to the Mark Anton Airport. The left engine was running increasingly rough, therefore, while on final for runway 3, the pilot shut the left engine down. The pilot attempted to extend the landing gear, however, he was unaware that the landing gear would have to be extended manually. The pilot began to manually extend the landing gear but could not get the gear down in time to land on the runway. The pilot reported that he attempted to make a go-around, however, the climb performance with only one engine was insufficient. The aircraft collided with terrain and caught fire. An inspection of the engine revealed that there was a significant loss of engine oil. The crankshaft oil seal had come out of the crankshaft bore, and had moved forward on the crankshaft. An inspection of the oil seal revealed that it was a "lipped" seal, which was not approved for this type of crankcase. Also, the engine manufacturer's representative reported that the sealant applied to the seal surface was not of a approved type. Aircraft maintenance records show that the crankshaft seal had been removed and replaced two months prior to the accident during the latest annual inspection. The aircraft had flown 48 hours since the maintenance work was conducted.