Narrative:

Small aircraft X being vectored for approach to denton inbound from the south. WX was a temperature inversion with an overcast layer from 2000- 4200 ft MSL and OAT of 29-30 degrees fahrenheit. We had been en route at 6000 ft above the clouds with an OAT of about 43 degrees fahrenheit. Approach gave descent to 3000 ft, at which time we became IMC and in the cold air. We began picking up light mixed ice and I notified approach as such. After a few min, icing became worse and IAS was decaying from 110 KTS to 90 KTS under full power. I asked for a climb back to warm air and was cleared to 4000 ft. At 4000 ft we were still in IMC and below freezing. Ice was not abating. The clouds were very thin above and I eased up to 4300 ft on which point we broke out. Approach advised we were not cleared to that altitude and to descend because they had traffic above at 5000 ft. I refused and said if she would not clear me higher, I would declare an emergency. Approach answered 'are you declaring an emergency?' and I said yes, and continued above the clouds and out of the ice. I was handed off to another controller who cleared me to 5000 ft at my request. At that altitude OAT was 38 degrees fahrenheit. We thawed out and landed at dto without further incident. Approach was very reluctant to help with my icing problem until I declared an emergency. ATC needs to take light plane icing very seriously. I believe it would have been very hazardous to follow instructions and descend back to icing conditions with a 1/4 inch load of ice accumulation. During preflight WX briefing, I specifically asked about icing and was told that icing airmets were canceled and there were no PIREPS of icing in the area.

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Original NASA ASRS Text

Title: SMA ENCOUNTERED ICING. CLB THROUGH ASSIGNED ALT, REFUSED CLRNC. DECLARED EMER.

Narrative: SMA X BEING VECTORED FOR APCH TO DENTON INBOUND FROM THE S. WX WAS A TEMP INVERSION WITH AN OVCST LAYER FROM 2000- 4200 FT MSL AND OAT OF 29-30 DEGS FAHRENHEIT. WE HAD BEEN ENRTE AT 6000 FT ABOVE THE CLOUDS WITH AN OAT OF ABOUT 43 DEGS FAHRENHEIT. APCH GAVE DSCNT TO 3000 FT, AT WHICH TIME WE BECAME IMC AND IN THE COLD AIR. WE BEGAN PICKING UP LIGHT MIXED ICE AND I NOTIFIED APCH AS SUCH. AFTER A FEW MIN, ICING BECAME WORSE AND IAS WAS DECAYING FROM 110 KTS TO 90 KTS UNDER FULL PWR. I ASKED FOR A CLB BACK TO WARM AIR AND WAS CLRED TO 4000 FT. AT 4000 FT WE WERE STILL IN IMC AND BELOW FREEZING. ICE WAS NOT ABATING. THE CLOUDS WERE VERY THIN ABOVE AND I EASED UP TO 4300 FT ON WHICH POINT WE BROKE OUT. APCH ADVISED WE WERE NOT CLRED TO THAT ALT AND TO DSND BECAUSE THEY HAD TFC ABOVE AT 5000 FT. I REFUSED AND SAID IF SHE WOULD NOT CLR ME HIGHER, I WOULD DECLARE AN EMER. APCH ANSWERED 'ARE YOU DECLARING AN EMER?' AND I SAID YES, AND CONTINUED ABOVE THE CLOUDS AND OUT OF THE ICE. I WAS HANDED OFF TO ANOTHER CTLR WHO CLRED ME TO 5000 FT AT MY REQUEST. AT THAT ALT OAT WAS 38 DEGS FAHRENHEIT. WE THAWED OUT AND LANDED AT DTO WITHOUT FURTHER INCIDENT. APCH WAS VERY RELUCTANT TO HELP WITH MY ICING PROB UNTIL I DECLARED AN EMER. ATC NEEDS TO TAKE LIGHT PLANE ICING VERY SERIOUSLY. I BELIEVE IT WOULD HAVE BEEN VERY HAZARDOUS TO FOLLOW INSTRUCTIONS AND DSND BACK TO ICING CONDITIONS WITH A 1/4 INCH LOAD OF ICE ACCUMULATION. DURING PREFLT WX BRIEFING, I SPECIFICALLY ASKED ABOUT ICING AND WAS TOLD THAT ICING AIRMETS WERE CANCELED AND THERE WERE NO PIREPS OF ICING IN THE AREA.

Data retrieved from NASA's ASRS site as of July 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.