NAV-4 PLT HAS ENG FAILURE ON FINAL TO SEE; CA. BLAMES IMPROPER CARB HEAT USE.

Narrative

WHILE ON 3 MI FINAL TO SEE FIELD; EL CAJON; CA; I WAS CLRED TO LAND ON RWY 27R. AT ABOUT A 2.5 MI FINAL; I COMPLETED THE LNDG CHKLIST BY INCREASING THE FLAP SETTING TO FULL WHEN I NOTICED THAT THE ENG DID NOT RESPOND TO THROTTLE MOVEMENT. I DECLARED AN EMER ON SEE TWR FREQ. I REVIEWED THE CHKLIST AGAIN; ADDING MORE CARB HEAT; INCREASING THE CARB AIR TEMP GAUGE TO APPROX 70 DEGS F; WHICH WAS AT OR ABOUT 45 DEGS F. I DOUBLECHKED THE FUEL VALVE AND FUEL BOOST PUMP WAS ON; AND CHKED FOR FUEL PRESSURE; WHICH WAS NORMAL; BUT BY THEN; THE PROP HAD CEASED ROTATION. I REDUCED THE FLAP SETTING TO 1/2 AND CONTINUED THE APCH; COMPLETING AN ENG-OUT LNDG. AFTER TOUCHDOWN; I ROLLED CLR OF THE RWY; STOPPING ON THE OTHER SIDE OF THE HOLD SHORT LINE ON THE EXIT TXWY. WHEN THE ACFT WAS FULLY STOPPED; I WENT THROUGH THE START CHKLIST AND STARTED THE ENG NORMALLY. AFTER SATISFYING MYSELF THAT THE ENG WOULD CONTINUE TO RUN; I CONTACTED GND CTL AND GAINED PERMISSION TO TAXI TO RETURN TO HANGAR PARKING; WHICH WAS ACCOMPLISHED WITHOUT FURTHER INCIDENT. IDLE WAS NORMAL; AS WAS THE IDLE MIXTURE INDICATION AT SHUTDOWN; UTILIZING THE MIXTURE CTL TO IDLE CUTOFF. I REQUESTED THAT MY MECH PERFORM A POST EVENT INSPECTION TO ENSURE THAT ALL SYS WERE OPERATING NORMALLY. HOWEVER; AT THIS POINT; I FEEL THAT I HAD INSUFFICIENT CARB HEAT SET FOR THE DAY; WHICH MAY HAVE ALLOWED ICE TO FORM IN THE CARB INTAKE; THUS CAUSING THE ENG TO STOP. HAVING SUFFICIENT ALT VERSUS DISTANCE TO THE RWY AFFORDED ME THE NECESSARY GLIDE ANGLE TO COMPLETE AN ENG OUT APCH AND LNDG. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR INDICATED THAT THIS ACFT HAS A PRESSURE CARB THAT REQUIRES A MINIMUM OF 4-6 PSI. THE AUX FUEL PUMP IS CALLED FOR ONLY WHEN NECESSARY AND WAS NOT ON. IF THE ENG PUMP DID NOT PROVIDE ADEQUATE PRESSURE AT IDLE THE ENG WILL STOP. MAINT FOUND NO MECHANICAL PROBS; HOWEVER; NEW O-RINGS WERE INSTALLED DURING THE INSPECTION. NO FURTHER PROBS HAVE BEEN OBSERVED AND THE RPTR NOW CONSIDERS IT NECESSARY TO USE THE AUX FUEL PUMP DURING APCHS AS A PRECAUTION. CARB HEAT WAS NOT USED BEFORE THE ENG PWR LOSS.