C172 PLT HAD MENTAL CONFUSION AND SICKNESS THAT WOULD INDICATE CARBON MONOXIDE POISONING.

Narrative

I WAS ENTERING THE TFC PATTERN AT (S27). THERE WAS A C172 ON L DOWNWIND FOR RWY 13. I ANNOUNCED ON THE RADIO THAT I WAS #2 ON L DOWNWIND FOR RWY 13. RIGHT AFTER MAKING THE ANNOUNCEMENT MY ENG WAS SPUTTERING DUE TO LACK OF FUEL CAUSED BY A HEADWIND. AT THAT POINT; I ANNOUNCED ON THE RADIO THAT I HAD ENG EMER AND NEEDED TO LAND IMMEDIATELY AS I WAS EVEN WITH THE END OF RWY 31. THE OTHER PLANE SAID HE WOULD GO AROUND. I MADE A SUCCESSFUL LNDG ON RWY 31 AND CLRED THE RWY. THE WIND WAS 180 DEGS AT 5 MPH. THE OTHERS C172 RESUMED ITS PATTERN AND LANDED SAFELY. I GASSED UP MY PLANE. IT TOOK 38.01 GALS ON TANKS THAT HAD 39 GALS USEABLE. THE PROB AROSE FROM A HEADWIND OCCURRING DURING THE LAST LEG OF 100 MI FLT FROM SEELY; LAKE MICHIGAN. I ALSO WAS EXPERIENCING LIGHT HEADEDNESS AND FELT NAUSEOUS. THESE SYMPTOMS CAME ON HALFWAY THROUGH THE LEG OF THE TRIP. I THINK THESE FACTORS LED TO ME CHOOSING TO LAND IMMEDIATELY INSTEAD OF STAYING ON DOWNWIND #2 OVER THE CITY OF KALISPELL. NO ONE WAS HURT; NO DAMAGE; NO CLOSE ENCOUNTER (AIRBORNE) WITH OTHER ACFT.