Narrative:

We departed with the west/C anti-ice on. The WX at ZZZ1 was about 3 SM visibility with an overcast layer around 1000 ft and temperature around 6 degrees C. As we turned north on the departure we went through an area of light-moderate precipitation according to the radar. As we climbed through this area we received ice annunciations from the ice detector and the precipitation changed to snow. Icing conditions continued during our climb. Climbing out of FL200 we got an 'anti-ice duct' warning message. The QRH had us turn off the 14TH stage bleed which left us with no ice protection; and we were still receiving ice indications. I had the first officer query ATC as to the tops in order to ascertain if we could clear icing conditions above the clouds. ATC informed us that they had no top reports in our area. The first officer reminded me that on our way from ZZZ2 to ZZZ1 a couple of hours earlier; that we had been in icing conditions the entire way to FL290. I had the first officer declare an emergency and ask for a descent with ATC as I brought up the airports on the FMS. We had just passed north of XXX VOR and the closest suitable airport we ascertained to be ZZZ. I xferred controls to the first officer and took over the radios. ATC had only given us a descent to FL190; and so I reiterated our declaration of emergency and our need to descend and divert to ZZZ provided the WX was suitable to land. ATC asked for our fuel; souls on board; and nature of our emergency; which I provided them. ATC then gave us a descent to 14000 ft. As we were in the descent; I programmed the FMS for our clearance to ZZZ and reviewed the QRH in order to confirm we had not missed anything it directed us to do. I also began to run the respective checklists in preparation for landing. At 14000 ft; we were in-between layers and during this time; I used a flashlight to see if there was any ice buildup on the windshield wipers. There did not appear to be any or that I could see on the main wingtip. I told ATC that we were in-between layers so for the time being wanted to stay there and descend quickly for the approach. ATC gave us pilot discretion to 5000 ft which was great. I then called the flight attendant and let her know what was happening and why we were diverting and that we would be on the ground in about 5-7 mins. I also let her know that we were so busy I would not be able to brief the passenger until we land and asked that she communicate our situation to the passenger; which she did. We descended to 5000 ft; and ran the approach check. ATC gave further descent to 3000 ft and vectors to the ILS xx approach to ZZZ. As the autoplt intercepted the localizer; for some reason (neither the first officer or I could figure out why); during a bump of turbulence the autoplt disconnected. I asked the first officer if the controls felt abnormal; because I thought maybe it had disconnected as a result of ice buildup. He said they felt normal. Because of the autoplt disconnecting we did not successfully intercept the localizer and were now high on the GS (about full scale) and over the FAF. We told approach that we need to have re-vectors; which they gave us. We were vectored at 3000 ft which kept our tat at +11 degree C -12 degrees C and we were not receiving the ice message. Our second time on the approach was successful with a nice soft touchdown by the first officer. I taxied off toward the terminal and was given clearance to taxi to the ramp. Once on the ramp area; the crash fire rescue equipment personnel inspected the exterior of the aircraft to ascertain if there was any visible damage. They returned a negative report and we taxied to the gate. When we had parked at the gate; I went back and explained to the passenger that the system which keeps the wings from icing up when flying in icing conditions had malfunctioned and in order to be safe; we had to get out of the ice which meant we had to land as soon as safely possible.

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Original NASA ASRS Text

Title: CRJ200 FLT CREW RECEIVES ANTI-ICE DUCT WARNING DURING CLIMB IN ICING CONDITIONS AND AFTER COMPLYING WITH QRH PROCEDURES; ELECTS TO DIVERT TO NEAREST SUITABLE ARPT FOR AN UNEVENTFUL LANDING.

Narrative: WE DEPARTED WITH THE W/C ANTI-ICE ON. THE WX AT ZZZ1 WAS ABOUT 3 SM VISIBILITY WITH AN OVCST LAYER AROUND 1000 FT AND TEMP AROUND 6 DEGS C. AS WE TURNED N ON THE DEP WE WENT THROUGH AN AREA OF LIGHT-MODERATE PRECIP ACCORDING TO THE RADAR. AS WE CLBED THROUGH THIS AREA WE RECEIVED ICE ANNUNCIATIONS FROM THE ICE DETECTOR AND THE PRECIP CHANGED TO SNOW. ICING CONDITIONS CONTINUED DURING OUR CLB. CLBING OUT OF FL200 WE GOT AN 'ANTI-ICE DUCT' WARNING MESSAGE. THE QRH HAD US TURN OFF THE 14TH STAGE BLEED WHICH LEFT US WITH NO ICE PROTECTION; AND WE WERE STILL RECEIVING ICE INDICATIONS. I HAD THE FO QUERY ATC AS TO THE TOPS IN ORDER TO ASCERTAIN IF WE COULD CLR ICING CONDITIONS ABOVE THE CLOUDS. ATC INFORMED US THAT THEY HAD NO TOP RPTS IN OUR AREA. THE FO REMINDED ME THAT ON OUR WAY FROM ZZZ2 TO ZZZ1 A COUPLE OF HRS EARLIER; THAT WE HAD BEEN IN ICING CONDITIONS THE ENTIRE WAY TO FL290. I HAD THE FO DECLARE AN EMER AND ASK FOR A DSCNT WITH ATC AS I BROUGHT UP THE ARPTS ON THE FMS. WE HAD JUST PASSED N OF XXX VOR AND THE CLOSEST SUITABLE ARPT WE ASCERTAINED TO BE ZZZ. I XFERRED CTLS TO THE FO AND TOOK OVER THE RADIOS. ATC HAD ONLY GIVEN US A DSCNT TO FL190; AND SO I REITERATED OUR DECLARATION OF EMER AND OUR NEED TO DSND AND DIVERT TO ZZZ PROVIDED THE WX WAS SUITABLE TO LAND. ATC ASKED FOR OUR FUEL; SOULS ON BOARD; AND NATURE OF OUR EMER; WHICH I PROVIDED THEM. ATC THEN GAVE US A DSCNT TO 14000 FT. AS WE WERE IN THE DSCNT; I PROGRAMMED THE FMS FOR OUR CLRNC TO ZZZ AND REVIEWED THE QRH IN ORDER TO CONFIRM WE HAD NOT MISSED ANYTHING IT DIRECTED US TO DO. I ALSO BEGAN TO RUN THE RESPECTIVE CHKLISTS IN PREPARATION FOR LNDG. AT 14000 FT; WE WERE IN-BTWN LAYERS AND DURING THIS TIME; I USED A FLASHLIGHT TO SEE IF THERE WAS ANY ICE BUILDUP ON THE WINDSHIELD WIPERS. THERE DID NOT APPEAR TO BE ANY OR THAT I COULD SEE ON THE MAIN WINGTIP. I TOLD ATC THAT WE WERE IN-BTWN LAYERS SO FOR THE TIME BEING WANTED TO STAY THERE AND DSND QUICKLY FOR THE APCH. ATC GAVE US PLT DISCRETION TO 5000 FT WHICH WAS GREAT. I THEN CALLED THE FLT ATTENDANT AND LET HER KNOW WHAT WAS HAPPENING AND WHY WE WERE DIVERTING AND THAT WE WOULD BE ON THE GND IN ABOUT 5-7 MINS. I ALSO LET HER KNOW THAT WE WERE SO BUSY I WOULD NOT BE ABLE TO BRIEF THE PAX UNTIL WE LAND AND ASKED THAT SHE COMMUNICATE OUR SITUATION TO THE PAX; WHICH SHE DID. WE DSNDED TO 5000 FT; AND RAN THE APCH CHK. ATC GAVE FURTHER DSCNT TO 3000 FT AND VECTORS TO THE ILS XX APCH TO ZZZ. AS THE AUTOPLT INTERCEPTED THE LOC; FOR SOME REASON (NEITHER THE FO OR I COULD FIGURE OUT WHY); DURING A BUMP OF TURB THE AUTOPLT DISCONNECTED. I ASKED THE FO IF THE CTLS FELT ABNORMAL; BECAUSE I THOUGHT MAYBE IT HAD DISCONNECTED AS A RESULT OF ICE BUILDUP. HE SAID THEY FELT NORMAL. BECAUSE OF THE AUTOPLT DISCONNECTING WE DID NOT SUCCESSFULLY INTERCEPT THE LOC AND WERE NOW HIGH ON THE GS (ABOUT FULL SCALE) AND OVER THE FAF. WE TOLD APCH THAT WE NEED TO HAVE RE-VECTORS; WHICH THEY GAVE US. WE WERE VECTORED AT 3000 FT WHICH KEPT OUR TAT AT +11 DEG C -12 DEGS C AND WE WERE NOT RECEIVING THE ICE MESSAGE. OUR SECOND TIME ON THE APCH WAS SUCCESSFUL WITH A NICE SOFT TOUCHDOWN BY THE FO. I TAXIED OFF TOWARD THE TERMINAL AND WAS GIVEN CLRNC TO TAXI TO THE RAMP. ONCE ON THE RAMP AREA; THE CFR PERSONNEL INSPECTED THE EXTERIOR OF THE ACFT TO ASCERTAIN IF THERE WAS ANY VISIBLE DAMAGE. THEY RETURNED A NEGATIVE RPT AND WE TAXIED TO THE GATE. WHEN WE HAD PARKED AT THE GATE; I WENT BACK AND EXPLAINED TO THE PAX THAT THE SYS WHICH KEEPS THE WINGS FROM ICING UP WHEN FLYING IN ICING CONDITIONS HAD MALFUNCTIONED AND IN ORDER TO BE SAFE; WE HAD TO GET OUT OF THE ICE WHICH MEANT WE HAD TO LAND AS SOON AS SAFELY POSSIBLE.

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.