A C182 ENRTE ENCOUNTERED ICING CONDITIONS AND DIVERTED. THE PLT HAD SOME DIFFICULTY FLYING THE APCH WITH ICE ACCUMULATION.

Narrative

THIS WAS A XCOUNTRY FLT FROM MINNEAPOLIS; MN; TO TAYLOR; TX; IN A C182 JUST PURCHASED THAT DAY IN MINNEAPOLIS. ACCOMPANYING ME ON THIS TRIP WAS ONE OF MY 2 PARTNERS; WHO IS ALSO INST RATED. I WAS PLTING THE FIRST LEG FROM FLYING CLOUD (FCM) THAT WAS FILED IFR TO EL RENO; OK. JUST S OF SIOUX CITY; WE ENCOUNTERED SOME PATCHES OF LIGHT ICING WHILE FLYING THROUGH CLOUDS. THROUGH SUBLIMATION; WE DID NOT KEEP ANY QUANTITY OF ICE FOR LONG. I ASKED FOR AND RECEIVED CLRNC FOR LOWER ALTS (5000-6000 FT BLOCK) TO STAY BTWN CLOUD LAYERS. WHEN APPROX 40 MI N OF SALINA; WE ADVISED ATC OF OUR WISH TO LAND IN SALINA; SO AS TO GET SOME FUEL AND GET OUT OF THE ICING CONDITIONS. MY INTENTION WAS TO FLY THE ILS APCH INTO SALINA; AND I ADVISED ATC OF THIS AND SET OUR LOC TO THE FREQ FOR RWY 35. THE GPS/COM WAS NOT; HOWEVER; SWITCHED TO CDI MODE (WHICH WOULD ACTIVATE THE GS INDICATOR) BUT WAS LEFT IN GPS MODE. WHILE BEING VECTORED AROUND THE E SIDE OF THE FIELD TO INTERCEPT THE LOC; WE ENCOUNTERED WHAT WE CONSIDERED SUBSTANTIAL ICING. APPROX 1/4 INCH BUILT UP ON THE LEADING EDGES OF THE STRUTS WHILE BEING DIRECTED TO DSND FROM 6000 FT TO 3200 FT. MUCH OF IT COLLECTED WHILE HOLDING 4000 FT MSL. IN ADDITION TO THE STRUTS; WE QUICKLY HAD THE WINDSHIELD COMPLETELY COVERED IN ICE AND THE LEADING EDGES OF THE WINGS HAD WHAT LOOKED TO BE 1/8 INCH THICK ICE. THE ICE ON THE WINGS EXTENDED BACK UNDER THE WINGS APPROX 6-7 INCHES. WE IMMEDIATELY TURNED OUR DEFROSTER UP AS HIGH AS IT WOULD GO. UPON BEING DIRECTED TO DSND TO 3200 FT TO INTERCEPT THE LOC; A SMALL PORTION OF ICE LOOSENED RIGHT ABOVE THE DEFROST VENT. AT THIS TIME; ATC INFORMED US WE HAD OVERSHOT THE LOC COURSE AND GAVE US A CORRECTIVE HDG OF 010 DEGS. SHORTLY THEREAFTER ATC SAID WE HAD OVERSHOT THE LOC AGAIN; AT WHICH TIME WE TOLD ATC OUR INSTS WERE NOT WORKING. AT THIS TIME; I REQUESTED VECTORS TO THE FIELD. I'M NOT EXACTLY SURE WHAT ALT WE WERE AT WHEN I MADE THIS REQUEST (I'M GUESSING 3200 FT) BUT ATC SAID WE WERE 'BELOW THE MINIMUM' FOR A VISUAL APCH AND THAT HE'D 'HAVE TO TAKE US BACK UP AND AROUND;' IF WE COULDN'T SEE THE FIELD YET. AT THIS POINT; ENOUGH OF THE WINDSHIELD ICE HAD CLRED SO THAT WE COULD SEE FORWARD SUFFICIENTLY AND THE GND WAS IN SIGHT. WE COULD NOT YET SEE THE FIELD. WE INFORMED ATC THAT WE HAD SIGNIFICANT ICE ACCUMULATIONS AT WHICH TIME ATC REPLIED HE WAS TURNING THE LIGHTS TO HIGH INTENSITY AND TO CONTINUE INBOUND. SECONDS LATER; THE FIELD CAME INTO VIEW AS WE CONTINUED TO SHED ICE. I KEPT OUR SPD ABOVE 100 KTS UNTIL OVER THE END OF THE RWY AND THE LNDG WAS UNEVENTFUL. THE MAJORITY OF THE ICE WAS GONE BY THE TIME WE ENTERED THE TXWY. I FEEL THAT ATC'S DECISION TO ALLOW US TO CONTINUE THE APCH WAS VITAL TO OUR SAFETY; AND WE ARE VERY APPRECIATIVE OF THEIR PROMPT ATTN.