Narrative:

Incident where trace to light rime icing was encountered in an aircraft (plain old C182) not equipped for icing; IFR flight plan. Forecasts for icing; but no 'known' icing from PIREP's. Filed and was cleared on an unpublished preferred route from boston area to south of nyc. Routing 'requires' 6000 ft. Have used this proposed routing (gdm; orw; CCC; dpk; jfk dixie) numerous times and always get 'as filed' instead of having to go around to etx or lhy -- serious deviations around jfk. This time; there was trace light rime in a cloud band 4000-7000 ft. Clear above. I requested; but was denied a climb to 8000 ft to avoid icing. Controllers stated that altitudes other than 6000 ft were not available. So; we stuck it out at 6000 ft; in and out of clouds; picking up some rime. South of jfk; we requested and received 8000 ft and eventually had to go to 10000 ft to be clear of the icing clouds. By this time; we had accumulated about 0.400 inches of rime ice which stayed with us until our landing. While the outcome of the flight was never in doubt; and the plane seems capable of carrying this amount of rime without significant deteriorating of performance; my course of action should have requested an 'immediate change of altitude' -- implying that while there isn't a current emergency; it could develop into one if an altitude change were not approved. The controllers were dealing with their needs; and I wasn't insistent enough to require a change (from ATC) for my needs regarding safety of flight.

Google
 

Original NASA ASRS Text

Title: AN IFR C182 PLT ENCOUNTERED LIGHT RIME ICING AND DID NOT FORCEFULLY REQUEST AN ALT CHANGE TO EXIT ICING CONDITIONS.

Narrative: INCIDENT WHERE TRACE TO LIGHT RIME ICING WAS ENCOUNTERED IN AN ACFT (PLAIN OLD C182) NOT EQUIPPED FOR ICING; IFR FLT PLAN. FORECASTS FOR ICING; BUT NO 'KNOWN' ICING FROM PIREP'S. FILED AND WAS CLRED ON AN UNPUBLISHED PREFERRED RTE FROM BOSTON AREA TO S OF NYC. ROUTING 'REQUIRES' 6000 FT. HAVE USED THIS PROPOSED ROUTING (GDM; ORW; CCC; DPK; JFK DIXIE) NUMEROUS TIMES AND ALWAYS GET 'AS FILED' INSTEAD OF HAVING TO GO AROUND TO ETX OR LHY -- SERIOUS DEVS AROUND JFK. THIS TIME; THERE WAS TRACE LIGHT RIME IN A CLOUD BAND 4000-7000 FT. CLR ABOVE. I REQUESTED; BUT WAS DENIED A CLB TO 8000 FT TO AVOID ICING. CTLRS STATED THAT ALTS OTHER THAN 6000 FT WERE NOT AVAILABLE. SO; WE STUCK IT OUT AT 6000 FT; IN AND OUT OF CLOUDS; PICKING UP SOME RIME. S OF JFK; WE REQUESTED AND RECEIVED 8000 FT AND EVENTUALLY HAD TO GO TO 10000 FT TO BE CLR OF THE ICING CLOUDS. BY THIS TIME; WE HAD ACCUMULATED ABOUT 0.400 INCHES OF RIME ICE WHICH STAYED WITH US UNTIL OUR LNDG. WHILE THE OUTCOME OF THE FLT WAS NEVER IN DOUBT; AND THE PLANE SEEMS CAPABLE OF CARRYING THIS AMOUNT OF RIME WITHOUT SIGNIFICANT DETERIORATING OF PERFORMANCE; MY COURSE OF ACTION SHOULD HAVE REQUESTED AN 'IMMEDIATE CHANGE OF ALT' -- IMPLYING THAT WHILE THERE ISN'T A CURRENT EMER; IT COULD DEVELOP INTO ONE IF AN ALT CHANGE WERE NOT APPROVED. THE CTLRS WERE DEALING WITH THEIR NEEDS; AND I WASN'T INSISTENT ENOUGH TO REQUIRE A CHANGE (FROM ATC) FOR MY NEEDS REGARDING SAFETY OF FLT.

Data retrieved from NASA's ASRS site as of January 2009 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.