Aircraft Accident/Incident Report

Rolla, Missouri 65401
Sunday, December 17, 2000 18:21 CST

The pilot conducted a pre-buy inspection of the airplane that lasted approximately 30 minutes. The pilot departed SUS in the PA-23 at 1700. Two pilots in a Cessna 182 departed SUS 5-7 minutes later. Both airplanes had the same route of flight with Odessa, TX, as their destination airport. The Cessna 182 encountered no problems along the route of flight. Between 1800 and 1821, the PA-23's flight track became erratic in heading and altitude. The radar data indicated the airplane's altitude started descending from 8,500 feet msl at 1809 to an altitude of 2,000 feet msl recorded at 1821, which was the last radar return recorded. Between 1809 and 1821, the radar data indicated the airplane's flight path was a series of inconstant descending turns that took the airplane in an easterly direction. The last radar return was approximately .5 nautical mile from the accident site. The airplane impacted the ground in a steep nose down attitude. The leading edges of the left and right wings exhibited leading edge crush. Cable continuity was confirmed to the flight controls. The propeller blades exhibited "S" bending, leading edge gouges and chordwise scratching. Broken tree branches and limbs were found that exhibited prop slashes and gray paint transfer. A toxicology test was performed but a carbon monoxide test could not be performed due to an inadequate blood sample. The NTSB Materials Laboratory examined the muffler and heater muff assembly and reported that a microscopic examination of the muffler portion revealed the internal wall exhibited oxidation damage. The report stated, "Many areas of the muffler fracture showed oxidation damage that penetrated through the wall. The oxidation damage areas on the fracture appeared black, consistent with a pre-existing fracture that was exposed to the environment for an extended period of time." The report stated, "By visual estimate, the total combined length of the oxidation damage areas that penetrated through the wall was at least 20% of the circumference of the body of the muffler." The report stated, "The examination of the fractures from the heat exchanger collector tube showed evidence of minor tinting which is consistent with short-term (post crash) exposure to heat." It stated, "The outer layer of the tube had a decaburized layer, typical of steel exposed to high temperature and the environment for an extended period of time. The fracture surface of the heater muff exhibited no evidence of tinting."

The pilot's inadequate preflight during the pre-buy inspection, the pilot's incapacitation due to carbon monoxide, and the fractured muffler.