Departure and Planned Arrival
The pilot departed on a night cross-country flight at 2230 CST. According to the wife of the passenger, the airplane was expected to arrive at its planned destination at 2330 CST. However, it did not arrive.
Wreckage Location
The wreckage was discovered approximately 4 miles northeast of an airport. The airport had been reporting instrument flight rules (IFR) conditions during the time the airplane was en route and after its planned arrival.
Aircraft Examination
An examination of the airframe and engine revealed no mechanical anomalies that would have prevented flight. The airplane had flown about 4 hours during the year prior to its latest annual inspection.
Muffler Condition
The ends of the airplane's muffler were corroded and had numerous pinhole-sized holes along its edges. The muffler's shroud had baked oil on its inside surface, and the muffler body had rust on both sides. A mechanic who inspected the muffler approximately 2 months before the accident stated that he noticed small pinhole-sized holes at the muffler's end but did not consider them serious or likely to cause a problem.
Toxicology Report
The pilot's toxicology report indicated a carbon monoxide concentration of about 26% in his blood.
Summary of Facts
The flight departed at night under unknown weather conditions; the destination was not reached. The wreckage was found near an airport reporting IFR conditions. No pre-existing mechanical issues were found in the airframe or engine. The muffler exhibited significant corrosion and pinhole holes, and the pilot's blood showed elevated carbon monoxide levels.