Carbon Monoxide Poisoning During General Aviation Flight (N8452P)

Flight Sequence and Loss of Consciousness The pilot climbed to 5,500 feet MSL and trimmed the airplane at cruise power settings. He set the GPS navigation system for a direct flight, engaged the autopilot, and switched the fuel selector to the left auxiliary fuel tank. The pilot recalled passing Herrington, Kansas, and setting his radios for arrival at Topeka, Kansas. From that point, he could not remember anything else about the flight until he awoke in a flat hay field near Cairo, Missouri. ## Aircraft Impact and Pilot Response The airplane touched down in a wings-level attitude and slid about 525 feet before hitting a fence and small trees. When the pilot initially awoke, he was confused and thought he was still airborne. He eventually walked to a farmhouse and waited another 1 to 1-1/2 hours before an ambulance arrived to take him to a hospital. ## Toxicology and Aircraft Inspection Blood was drawn after the pilot was transported to the hospital. Toxicology tests of his blood showed 26.8% saturation with carbon monoxide. Inspection of the airplane revealed that the right muffler had a crack around one of its seams, which allowed exhaust fumes into the cabin heater housing and into the cabin. The airplane had recently been taken to an airplane service center for an annual inspection. The pilot decided to fly the airplane before the annual inspection had been signed off.