NTSB Identification: NYC93LA031 For details, refer to NTSB microfiche number 48322A

Accident occurred OCT-31-92 at MT. GILEAD, OH
Aircraft: CESSNA 150H, registration: N6402S
Injuries: 1 Serious.

THE PILOT WAS IN RADIO CONTACT WITH THE CONTROL TOWER AT THE DESTINATION AIRPORT AND IN A DESCENT FROM FIVE THOUSAND FEET TO TWO THOUSAND FEET IN PREPARATION FOR LANDING. SEVEN MILES SOUTH OF THE AIRPORT, THE AIRPLANE WAS OBSERVED, ON RADAR, FLYING AWAY FROM THE AIRPORT WHEN RADAR CONTACT WAS LOST. GROUND WITNESSES SAW THE AIRPLANE FLYING STRAIGHT AND LEVEL AT A LOW ALTITUDE OVER A WOODED AREA WHEN THE LEFT WING STRUCK A TREE. A TOXICOLOGY ON THE PILOT REVEALED CARBON MONOXIDE IN THE PILOT'S BLOOD. EXAMINATION OF THE LEFT HEATER/EXHAUST MUFFLER, THE SOURCE OF HEAT TO THE CABIN, SHOWED IT HAD DETERIORATED AND HAD THREE CRACKS. TWO CRACKS WHERE FOUND ON THE MUFFLER TUBE AND ONE ON THE FORWARD END PLATE. THE THREE CRACKS WERE INTERGRANULAR AND SHOWED SOME OXIDATION.
Probable Cause
PILOT INCAPACITATION DUE TO CARBON MONOXIDE GAS AS A RESULT OF CRACKS IN THE HEATER MUFFLER. A FACTOR IN THE ACCIDENT WAS THE PROGRESSIVE DETERIORATION OF THE LEFT HEATER MUFFLER.