ACFT EQUIP PROB MANDATES THAT A PVT PLT IN HIS C150H DIVERT TO ANOTHER ARPT AFTER DECLARING AN EMER WITH APCH CTLR AT AUG; GA.

Narrative

WHILE CRUISING AT 6500 FT MSL IN MY C150H; THE ENG BEGAN RUNNING ROUGH. I APPLIED FULL CARB HEAT AND FULL THROTTLE TRYING TO MAINTAIN LEVEL FLT. AFTER A COUPLE MINS AND NO IMPROVEMENT; I THOUGHT I SHOULD LEAN THE MIXTURE FURTHER TO COMPENSATE FOR THE CARB HEAT. (I HAD ALREADY LEANED FOR CRUISE.) WHEN EVEN THE SLIGHTEST ADDITIONAL LEANING CAUSED THE ENG TO CUT OUT; I WENT TO FULL RICH. THE ENG WAS STILL RUNNING (THOUGH VERY ROUGH); BUT NOT DEVELOPING ENOUGH PWR TO MAINTAIN ALT. HAVING TRIED EVERYTHING ELSE; I PUSHED THE CARB HEAT IN (TO FULL COLD). AT THIS POINT; THE ENG QUIT ALTOGETHER. I RETURNED THE CARB HEAT TO FULL HOT; PUSHED THE NOSE DOWN AND THE ENG STARTED RUNNING AGAIN; STILL AT LESS THAN NORMAL PWR AND VERY ROUGH. I WAS ON A VFR FLT PLAN AND HAD ASKED AUGUSTA APCH FOR RADAR TA'S. THEY HAD GIVEN ME A XPONDER CODE AND RADAR VECTORS. I WAS WITHIN THEIR TRSA; BUT WELL AWAY FROM THEIR CLASS D AREA. SINCE I WAS ON THEIR FREQ WHEN THE ENG PROB OCCURRED; I DECLARED AN EMER. THE CTLR OFFERED ME A CHOICE OF BUSH FIELD (CTLED) AND DANIEL FIELD (UNCTLED). I HAD NEVER LANDED AT EITHER AND THERE WERE A COUPLE OF EXCHANGES ON THE RADIO (DURING WHICH I CONFUSED THE 2 NAMES) BEFORE I REALIZED THAT I SHOULD LAND AT DANIEL WHICH WAS THE ARPT THAT I HAD IN SIGHT AT THE TIME. ONCE I WAS COMMITTED TO DANIEL FIELD; THE CTLR SAID THE USUAL; 'RADAR SVC TERMINATED; FREQ CHANGE APPROVED; SQUAWK VFR.' ON THE WAY DOWN; WHEN I HAD THE ARPT MADE; I PULLED THE THROTTLE BACK TO IDLE; IT SEEMED SMOOTHER; BUT THEN IT WAS AT IDLE. I MADE A NORMAL LNDG. AFTER LNDG; I CUT OFF THE CARB HEAT (OUT OF HABIT) AND ADDED PWR TO TAXI. NO PROB. ONCE STOPPED; I DID A RUN-UP WHICH WAS TOTALLY NORMAL. IT OCCURRED TO ME THAT THE INTAKE AIR FILTER MIGHT HAVE ICED OVER; BUT THE AIR WAS CLR AND WELL ABOVE FREEZING; EVEN AT 6500 FT. THERE WAS A FAIRLY IMPRESSIVE SHOP AT DANIEL FIELD. (I HAD NEVER LANDED AT THAT ARPT BEFORE.) APPARENTLY; ATC HAD TOLD THEM TO EXPECT ME. THEY WERE ABLE TO PUT A MECH ON IT RIGHT AWAY. HE DID A GND RUN-UP AND FOUND NO PROB. HE THEN CHKED IT OVER VISUALLY PRETTY THOROUGHLY. HE CHKED THE FILTER AND REMOVED IT TO INSPECT THE AIR BOX. ALL WAS OK. FINALLY; HE DECIDED THAT ONE OF THE INTAKE PIPES WAS NOT LINED UP PROPERLY AND THAT IT HAD PROBABLY BEEN LEAKING. HE REMOVED THE PIPE AND REPLACED IT; PROPERLY ALIGNED. AFTER THE REPAIR; EVERYTHING CHKED OUT OK (AS IT HAD BEFORE THE REPAIR). HAVING SIGNED OFF THE REPAIR; HE SENT ME ON MY WAY. INCIDENTALLY; ABOUT 5 MINS AFTER I LANDED; WHILE I WAS DESCRIBING THE PROB TO THE MECH; THE LCL CITY FIRE DEPT SHOWED UP. APPARENTLY; ATC HAD ALSO CALLED THEM. I DO NOT KNOW WHAT CAUSED THE PROB OR WHAT COULD HAVE BEEN DONE TO PREVENT IT. THE CTLR WAS PROFESSIONAL AND HANDLED THE SIT WELL.