Date: 201306
Local time of day: 0601-1200
Location: ZDC.ARTCC, VA
Flight conditions: VMC
Weather elements / visibility: Rain; 6
Light: Daylight
Aircraft: Cessna 150
Operator: Personal
Operating under: Part 91
Flight plan: None
Mission: Personal
Flight phase: Descent
Airspace: Class E ZDC
ATC / advisory: Center ZDC
Aircraft component: Reciprocating Engine Assembly
Component problem: Malfunctioning
Reporter organization: Personal
Reporter function: Pilot Flying; Single Pilot
Reporter qualification: Flight Crew Private
Anomaly: Aircraft Equipment Problem Less Severe; Inflight Event / Encounter Weather / Turbulence
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Issued Advisory / Alert; Flight Crew Took Evasive Action; Flight Crew Overcame Equipment Problem
Contributing factors: Weather; Human Factors; Aircraft
Primary problem: Ambiguous

Narrative: I have ADS-B and XM Weather onboard which I use to show textual weather information. Enroute to CKB at 6;500 FT; I checked weather information at nearby airports in the mountains for ceiling information. Most of the stations were reporting either clear below 12;000; or broken at 10;000. I made a PIREP to report that it was in fact overcast at 7;000. On the ground at CKB; I checked the weather again and observed the same ceiling information; either broken at 10 or clear below 12 thousand. I decided to use 6;500 FT to fly back; knowing the ceiling was at 7;000. After taking off; I saw the ceiling had dropped below 7;000; so I decided to climb to 11;500 to climb over the clouds. Upon reaching 11;300 FT; I experienced a loss of RPM and determined it to be carburetor icing. I applied carburetor heat and completed the necessary checklist items. Because I did not have full RPM; I was unable to maintain altitude and initiated a descent. I advised Washington Center that I was descending and wasn't sure what altitude I would level out at; but I would let him know. During my descent; I turned to the south and found a gap in the clouds. This gap required a steep descent to prevent from going into IMC. During the descent; I tried my best to maintain the VFR Cloud Separation Minimums; and was in VMC the entire time. When I leveled out below the cloud layer; Washington Center advised me that he had lost radar contact. I notified him that I would be diverting to a nearby airport. Also; my engine had returned to normal. Washington Center asked me if 'I could see the ground'. I responded 'Yes' and that I was about '600 FT below the clouds'. Washington Center then asked if I could go IFR. I responded that I couldn't. Then Washington Center said something along the lines of 'ok; you're IFR but the aircraft isn't?' I responded that it was 'the other way around' and that I was not IFR rated. Washington Center than asked for an aircraft at another local airport to report the ceiling at their location. This ceiling information differed from the location that I was at. After experiencing carburetor icing and performing a descent; I leveled out at a safe altitude below the clouds. I never went into IMC; and maintained VFR to the best of my ability. The carb heat worked as it should have; and the engine came back to normal. The flight resumed as normal. The reason I am filing this report is because while I descended through a gap in the clouds; I may not have been exactly 2;000 FT horizontal; 500 FT below; and 1;000 FT above the clouds; but I was in VMC and never went into IMC. I don't know why Washington Center asked so many questions; but I felt they were irrelevant and distracting. As a young pilot; I don't know if this is normal or not.




Synopsis: C150 pilot discovers that the ceiling is much lower than reported on a flight to CKB.  On the return flight an attempt is made to climb over the clouds resulting in carburetor ice and a descent through a small hole to VMC below. The engine returns to normal but the reporter elects to divert to a suitable airport.