Incident Overview
During a cross-country flight, the pilot and a pilot-rated passenger (PRP) experienced a medical emergency approximately 25 minutes after departure. The PRP contacted Air Traffic Control (ATC) to report that the pilot was unwell. Both ATC personnel and the pilot of another aircraft attempted to assist the PRP in managing the situation.
Progression of Events
Despite these efforts, the PRP reported feeling tired and nauseated after roughly 20 minutes of communication. No further transmissions were received from the aircraft. The airplane continued flying for an additional one and a half hours before descending into a heavily wooded area, resulting in a crash.
Technical Findings
Examination of the wreckage identified significant mechanical defects. Cracks and heavy pitting corrosion were found on the muffler case. This damage allowed exhaust gases to leak into the space between the muffler and the shroud, subsequently entering the cabin area.
Toxicological Evidence
Post-accident toxicological tests confirmed that both occupants had elevated carbon monoxide levels. The pilot’s blood contained 43% carbon monoxide, while the PRP’s level was measured at 69%. These findings indicate severe exposure to toxic fumes generated by the aircraft's exhaust system.
Maintenance History
Records indicated that the airplane had completed an annual inspection one year prior to the accident. Since that inspection, the aircraft had accumulated more than 88 hours of flight time.