Narrative:

Descending into our destination in IMC we were being vectored for an ILS approach. On downwind leg I identified and checked the NAVAID. Once the localizer was intercepted the needle started fluctuating excessively. At the same time we started picking up freezing rain outside the FAF. I inquired with ATC about the localizer fluctuation and was informed all needles were in the green; however another voice came on the frequency and stated that 'xx was working in the localizer shack.' outside the FAF we received a stabilizer anti ice fail message which went away with a generous application of power. At the marker the localizer was still fluctuating excessively and I initiated a missed approach. I informed ATC. On climb out from the missed approach we received a wing and stabilizer ice fail message. We were still accumulating significant ice and I asked ATC to continue the climb into warmer air. At around four thousand the OAT was high enough to shed the ice. We continued the climb to eight thousand while completing the QRH items for wing and stabilizer ice fail. An air carrier flight was inbound and I asked approach to inform him about the localizer fluctuation and the freezing rain and ice. The crew elected to shoot the approach and landed with no problems. They reported a steady localizer and no problems with ice. I informed ATC that we would like to try the approach again. We started our descent and intercepted the localizer outside the FAF. While tracking inbound at 2300 ft we again started picking up ice and freezing rain. The localizer was steady this time so we continued. Approaching the FAF we received a bleed one leak warning followed by a wing and stabilizer ice fail caution. At this time the ice and freezing rain were getting worse and I again abandoned the approach and started an immediate climb to warmer OAT. We again completed the QRH items and elected to divert to our planned alternate. We received our clearance to the alternate and I informed ATC that I was declaring an emergency. I informed the flight attendants to prepare for precautionary landing and made PA announcement to the passengers. Enroute I checked with ATC about any icing on the descent. I was informed that no one had reported any ice. We checked in with approach and were assigned runway xl ILS approach. I informed the controller we were requesting runway Y ILS if was ok unless the equipment was set up for an adjacent runway. He said runway Y was ok with them. We commenced the approach and upon breaking out and landing we found that there was no emergency equipment waiting for us. After clearing the runway I asked the tower if they were aware that we had declared an emergency. They informed me that they had not been informed and immediately asked if we needed any assistance. I said no and continued to the gate. The whole reason I declared the emergency was so that someone would be available to get the passengers off if something went wrong. A bleed leak re-occurrence could have easily led to an in-flight engine shutdown or worse yet a fire. Fortunately all worked out well and airport rescue and fire fighting was not actually needed. I'm not sure whether or not 'xx working in the localizer shack' had anything to do with the first missed approach. It could have been ice on the navigation antennas on the vertical fin. I do know that the localizer was steady on the second approach. I would hope that if maintenance was being performed that the system would have been NOTAM'd out of service. The second approach was abandoned due the anti ice system and bleed leak malfunction. My main concern with this event is the fact that somewhere between center and approach or tower the communication chain broke down. I would have liked a better idea of exactly what the weather was doing at our original destination. The dispatch release matched my own research and nowhere was there a mention of any freezing rain. Not even on ATIS had anyone reported any problems. Perhaps a simple nexrad radar picture would have shown the freezing rain and we would have had a better idea of what to expect.

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Original NASA ASRS Text

Title: An EMB145 crew picked up freezing rain on an ILS approach with the LOC fluctuating excessively. A go around was executed and the airfoil anti ice system failed. After attempting a second approach an emergency was declared and the flight diverted to its alternate which was ice free.

Narrative: Descending into our destination in IMC we were being vectored for an ILS Approach. On downwind leg I identified and checked the NAVAID. Once the localizer was intercepted the needle started fluctuating excessively. At the same time we started picking up freezing rain outside the FAF. I inquired with ATC about the localizer fluctuation and was informed all needles were in the green; however another voice came on the frequency and stated that 'XX was working in the localizer shack.' Outside the FAF we received a STAB ANTI ICE FAIL message which went away with a generous application of power. At the marker the localizer was still fluctuating excessively and I initiated a missed approach. I informed ATC. On climb out from the missed approach we received a WING AND STAB ICE FAIL message. We were still accumulating significant ice and I asked ATC to continue the climb into warmer air. At around four thousand the OAT was high enough to shed the ice. We continued the climb to eight thousand while completing the QRH items for WING AND STAB ICE FAIL. An air carrier flight was inbound and I asked approach to inform him about the LOC fluctuation and the freezing rain and ice. The crew elected to shoot the approach and landed with no problems. They reported a steady LOC and no problems with ice. I informed ATC that we would like to try the approach again. We started our descent and intercepted the localizer outside the FAF. While tracking inbound at 2300 FT we again started picking up ice and freezing rain. The LOC was steady this time so we continued. Approaching the FAF we received a BLEED ONE LEAK warning followed by a WING AND STAB ICE FAIL caution. At this time the ice and freezing rain were getting worse and I again abandoned the approach and started an immediate climb to warmer OAT. We again completed the QRH items and elected to divert to our planned alternate. We received our clearance to the alternate and I informed ATC that I was declaring an emergency. I informed the flight attendants to prepare for precautionary landing and made PA announcement to the passengers. Enroute I checked with ATC about any icing on the descent. I was informed that no one had reported any ice. We checked in with approach and were assigned Runway XL ILS Approach. I informed the Controller we were requesting Runway Y ILS if was OK unless the equipment was set up for an adjacent Runway. He said Runway Y was OK with them. We commenced the approach and upon breaking out and landing we found that there was no emergency equipment waiting for us. After clearing the runway I asked the Tower if they were aware that we had declared an emergency. They informed me that they had NOT been informed and immediately asked if we needed any assistance. I said no and continued to the gate. The whole reason I declared the emergency was so that someone would be available to get the passengers off if something went wrong. A bleed leak re-occurrence could have easily led to an in-flight engine shutdown or worse yet a fire. Fortunately all worked out well and Airport Rescue and Fire Fighting was not actually needed. I'm not sure whether or not 'XX working in the localizer shack' had anything to do with the first missed approach. It could have been ice on the NAV antennas on the vertical fin. I do know that the localizer was steady on the second approach. I would hope that if maintenance was being performed that the system would have been NOTAM'd out of service. The second approach was abandoned due the anti ice system and bleed leak malfunction. My main concern with this event is the fact that somewhere between Center and Approach or Tower the communication chain broke down. I would have liked a better idea of exactly what the weather was doing at our original destination. The dispatch release matched my own research and nowhere was there a mention of any freezing rain. Not even on ATIS had anyone reported any problems. Perhaps a simple NEXRAD radar picture would have shown the freezing rain and we would have had a better idea of what to expect.

Data retrieved from NASA's ASRS site as of April 2012 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.