Cessna 150
Flight Crew Instrument; Flight Crew Commercial
Flight Crew Last 90 Days 18; Flight Crew Total 2149; Flight Crew Type 1478
Troubleshooting
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Overcame Equipment Problem
Weather; Aircraft; Manuals
I was proceeding; by pilotage; at 4;500 feet. Abeam and east of ZZZ; I had a sudden interruption of power; a surge; and a further interruption. At the time; I was receiving Flight Following from Approach. Since emergency landing sites are very poor in the area; I decided to head to ZZZ. I was able to retain intermittent power by pumping the throttle. I first enriched mixture; but did not apply carburetor heat until later in in the glide when the engine was probably too cool to take effect. Approach turned me over to ZZZ Tower who cleared me to land on Runway XXR. I was able to make a right base approach and high final until I had the field made and performed a normal full flap landing. The engine was still running and I was able to clear the runway without interfering with other traffic.Carburetor icing was undoubtedly the problem; but I misdiagnosed it due to the sudden reduction of power. Prior experiences with carburetor icing were a gradual reduction in power. Instead of applying carburetor heat immediately; I richened mixture thinking I had a fuel contamination or sticking valve problem. I had plenty of fuel on board and subsequent examination of the sumps were clear. A full power run-up confirmed my opinion.In this case; I violated my personal rule to apply carburetor heat on first sensing an engine problem; having been misled by the sudden severe power reduction. Also; the Emergency Checklist was in the glovebox; but I decided not to fumble around for it because of the simplicity of the airplane and my familiarity with it. I intend to make up a separate Emergency Checklist and keep it on the glare shield for quick access. I also intend to drill myself on carburetor heat FIRST.
C150 pilot reported incorrectly diagnosing engine vibration due to carburetor icing.