TOI TWR DISREGARDED A PLT'S REQUEST TO LAND IN AN EMER CONDITION CAUSING THE PLT TO THINK THAT HE HAD TO LAND OFF ARPT.

Narrative

THE CAUSE OF ENG PWR LOSS WAS; I BELIEVE IMPROPER USE OF CARB HEAT. ALTHOUGH I FOLLOWED THE CHKLIST FOR THE C-150; APPLICATION OF CARB HEAT AT THE START OF MY DSCNT MAY HAVE PREVENTED SUDDEN PWR LOSS. THE CHKLIST SAID TO TURN ON CARB HEAT PRIOR TO 'CLOSING THE THROTTLE.' IT SHOULD READ; PRIOR TO 'REDUCING THROTTLE' FOR DSCNT. ON NOV/XX/94; I WAS ON A VFR FLT FROM BIRMINGHAM; AL; TO ENTERPRISE; AL; WITH A PLANNED REFUELING STOP AT TROY; AL; AT APPROX XA00 HRS AND 10 MI N OF TROY ARPT; I CONTACTED TROY TWR FOR LNDG INSTRUCTIONS. TROY TWR TOLD ME TO ESTABLISH A L BASE FOR RWY 07. I BEGAN MY DSCNT BY REDUCING PWR FROM 2500 RPM TO 2200 RPM (RPM REMAINED IN THE GREEN ARC) AND INCREASED MY AIRSPD BY REDUCING PITCH TO 115 MPH (STILL IN THE GREEN ON AIRSPD). AS I BEGAN TO LEVEL OFF FOR TFC PATTERN ALT (1900 FT MSL); THE ENG SUDDENLY 'COUGHED' AND SHOOK. I NOTICED A DROP IN RPM SO I APPLIED CARB HEAT. THE ENG SEEMED TO RUN ROUGHER SO I CLOSED THE CARB HEAT AND TURNED TO THE L AND HEADED STRAIGHT FOR THE ARPT END LINED UP WITH RWY 14. I CALLED THE TWR AND DECLARED AN EMER AND TOLD THEM THAT I WAS LOSING ENG PWR. I SAID THAT I WANTED TO LAND ON RWY 14. THE TWR AGAIN TOLD ME TO LAND ON RWY 7. I DID NOT WANT TO CONTINUE TO RWY 7 SINCE IT WAS SEVERAL MI AWAY. I EXPECTED THE TWR TO TELL ALL OTHER ACFT; INCLUDING THE ONE LNDG ON RWY 07; TO STAY CLR SO THAT I COULD LAND ON RWY 14. AT THIS POINT; I WAS FACED WITH 2 MAJOR CONCERNS: 1) IF I CONTINUED TO RWY 14; WOULD I CAUSE AN ACCIDENT WITH ACFT LNDG AND TAKING OFF OF THE ACTIVE RWY 07? 2) IF THE ENG CONTINUED TO LOSE PWR; WOULD I CRASH INTO THE DENSE FOREST BTWN ME AND RWY 14? THE ONLY SUITABLE LNDG AREA BTWN ME AND RWY 14 WAS A LARGE OPEN FIELD. I DECIDED TO LAND IN THE FIELD WHILE I HAD ENG PWR AND ENSURE THAT I WOULD NOT CAUSE AN ACCIDENT WITH LNDG OR DEPARTING TFC. I INFORMED TWR THAT I WAS LNDG APPROX 2 MI NW OF RWY 14 IN AN OPEN FIELD. ONCE LNDG WAS ASSURED; I CLOSED THE THROTTLE; TURNED OFF THE MAGNETOS; MADE ONE LAST CALL; AND TURNED OFF THE MASTER SWITCH (MAGNETOS AND MASTER SWITCH WERE TURNED OFF AS PRECAUTION AGAINST POST CRASH FIRE). I MADE AN EXCELLENT LNDG TO LEVEL GND AND STOPPED WITH NO INJURY OR DAMAGE TO THE PLANE. I TURNED PWR BACK ON AND INFORMED TWR THAT EVERYTHING WAS OK. THEY DISPATCHED POLICE AND FIRE UNITS TO THE SCENE. I MADE A FULL POLICE RPT AND BOTH POLICE AND FIRE UNITS LEFT AS SOON AS THEY SAW THAT THERE WAS NO DAMAGE OR INJURY. I CALLED THE OWNER AND TOLD HIM WHAT HAPPENED. HE ARRIVED AT DUSK AND DETERMINED THAT I HAD BTWN 30-40 MIN OF FUEL REMAINING IN THE TANKS. HE SUSPECTED CARB ICE. HE FLEW THE PLANE OUT OF THE FIELD THE FOLLOWING MORNING AND RETURNED TO HOME BASE WITHOUT INCIDENT.