Narrative:

I departed C59 VFR 3/89. The WX was MVFR, ceilings 2500-3500' overcast, visibility 3-5 mi, fog and ground showers. I'd received a standard briefing earlier that morning when I filed my flight plan, and received an update just prior to departure. I don't recall if there were flight precautions for icing conditions, but I think there were and there was a PIREP for light to moderate rime in the clouds. I was unable to raise rockford or greenbay FSS, or rockford approach to obtain my IFR clearance, so I proceeded VFR direct to lnr VOR. I considered just proceeding VFR, but observed reduced visibility conditions in the distance. Since it appeared my route would go IMC at my present altitude of 2500' MSL, I again tried to obtain my IFR clearance through msn approach. Approach cleared me to lnr direct at 4000'. I again noticed the beginnings of rime ice accumulation. I requested 6000', believing the tops to be in the 5000-6000' range, but had difficulty in the climb due to more rapid than expected ice accumulation. I experienced a pre-stall buffet and reduced angle of attach, which in turn, produced a negative rate of climb as I reached 6000'. I asked approach if she knew where the tops were and she reported 6300' MSL. I said I needed higher and she cleared me to 7000'. Unable to initiate a climb and with cruise speed falling, I made the decision to go down while the aircraft was still ctlable. I requested lower and was immediately cleared to 3000'. I reached VFR conditions just before reaching 3000'. I cancelled IFR, requested flight following, and headed on to lnr, about 35 NM away. Upon landing and visibility inspection, the airframe leading edges and surfaces carried about 3/8-1/2' of rime ice. Some accumulation probably sublimated in the 20-30 min flight to lnr after reaching VFR conditions. Initial observations of airframe components for ice accumulation were of the pitot probe, which is heated. (I turned on the heat myself prior to departure.) this might have delayed confirmation of ice accumulation. Proceeding into known or forecast icing conditions with inadequately equipped aircraft. What can be done to prevent a recurrence: descend to VFR upon encountering ice rather than attempting a climb, don't attempt IFR in IMC in any way conducive to airframe icing, and don't watch a heated pitot tube for initial signs of ice accumulation.

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Original NASA ASRS Text

Title: GA SMA ENCOUNTER WITH ICING.

Narrative: I DEPARTED C59 VFR 3/89. THE WX WAS MVFR, CEILINGS 2500-3500' OVCST, VISIBILITY 3-5 MI, FOG AND GND SHOWERS. I'D RECEIVED A STANDARD BRIEFING EARLIER THAT MORNING WHEN I FILED MY FLT PLAN, AND RECEIVED AN UPDATE JUST PRIOR TO DEP. I DON'T RECALL IF THERE WERE FLT PRECAUTIONS FOR ICING CONDITIONS, BUT I THINK THERE WERE AND THERE WAS A PIREP FOR LIGHT TO MODERATE RIME IN THE CLOUDS. I WAS UNABLE TO RAISE ROCKFORD OR GREENBAY FSS, OR ROCKFORD APCH TO OBTAIN MY IFR CLRNC, SO I PROCEEDED VFR DIRECT TO LNR VOR. I CONSIDERED JUST PROCEEDING VFR, BUT OBSERVED REDUCED VISIBILITY CONDITIONS IN THE DISTANCE. SINCE IT APPEARED MY ROUTE WOULD GO IMC AT MY PRESENT ALT OF 2500' MSL, I AGAIN TRIED TO OBTAIN MY IFR CLRNC THROUGH MSN APCH. APCH CLRED ME TO LNR DIRECT AT 4000'. I AGAIN NOTICED THE BEGINNINGS OF RIME ICE ACCUMULATION. I REQUESTED 6000', BELIEVING THE TOPS TO BE IN THE 5000-6000' RANGE, BUT HAD DIFFICULTY IN THE CLB DUE TO MORE RAPID THAN EXPECTED ICE ACCUMULATION. I EXPERIENCED A PRE-STALL BUFFET AND REDUCED ANGLE OF ATTACH, WHICH IN TURN, PRODUCED A NEGATIVE RATE OF CLB AS I REACHED 6000'. I ASKED APCH IF SHE KNEW WHERE THE TOPS WERE AND SHE RPTED 6300' MSL. I SAID I NEEDED HIGHER AND SHE CLRED ME TO 7000'. UNABLE TO INITIATE A CLB AND WITH CRUISE SPD FALLING, I MADE THE DECISION TO GO DOWN WHILE THE ACFT WAS STILL CTLABLE. I REQUESTED LOWER AND WAS IMMEDIATELY CLRED TO 3000'. I REACHED VFR CONDITIONS JUST BEFORE REACHING 3000'. I CANCELLED IFR, REQUESTED FLT FOLLOWING, AND HEADED ON TO LNR, ABOUT 35 NM AWAY. UPON LNDG AND VIS INSPECTION, THE AIRFRAME LEADING EDGES AND SURFACES CARRIED ABOUT 3/8-1/2' OF RIME ICE. SOME ACCUMULATION PROBABLY SUBLIMATED IN THE 20-30 MIN FLT TO LNR AFTER REACHING VFR CONDITIONS. INITIAL OBSERVATIONS OF AIRFRAME COMPONENTS FOR ICE ACCUMULATION WERE OF THE PITOT PROBE, WHICH IS HEATED. (I TURNED ON THE HEAT MYSELF PRIOR TO DEP.) THIS MIGHT HAVE DELAYED CONFIRMATION OF ICE ACCUMULATION. PROCEEDING INTO KNOWN OR FORECAST ICING CONDITIONS WITH INADEQUATELY EQUIPPED ACFT. WHAT CAN BE DONE TO PREVENT A RECURRENCE: DSND TO VFR UPON ENCOUNTERING ICE RATHER THAN ATTEMPTING A CLB, DON'T ATTEMPT IFR IN IMC IN ANY WAY CONDUCIVE TO AIRFRAME ICING, AND DON'T WATCH A HEATED PITOT TUBE FOR INITIAL SIGNS OF ICE ACCUMULATION.

Data retrieved from NASA's ASRS site as of August 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.