Narrative:

While on the ILS DME; we were using FMS/GPS to navigate and the autopilot had just initiated the procedure turn outbound. We were beginning to accrete mixed ice and had just activated the wing anti-ice. Approximately 30 seconds later we received a master warning; anti ice duct; followed by a master caution; anti ice duct. The first officer (pilot not flying) pulled out the fom and I selected the anti-ice page on the mfd and noticed that the system had closed the bleed valves to the wings. I then looked back to the pfd and noticed that the aircraft has not initiated the procedure turn inbound and was still tracking on the outbound heading; so I placed the aircraft into the heading mode and began to turn it manually. We also initiated a decent to get out of icing conditions and to get to the authorized altitude for the inbound course. As the inbound course was coming alive; ATC asked if we were inside 10 miles of the IAF. We responded 'yes.' he said that he showed us at 12 miles. This is possible since the autopilot had not initiated the procedure turn inbound and it had taken me a few seconds to recognize that and initiate the turn manually. Nonetheless; when queried by ATC; we were well inside the 10 mile ring and have no recollection of passing the 10 mile ring from the IAF. At approximately 10;000 ft; we exited IMC and continued the ILS approach with no further incidents. This was the second maintenance write up for an anti ice duct warning message in two days.this was one of those situations where everything happens at the same time. It started with a master warning that eliminated our anti ice capability as we were picking up moderate mixed ice. I diverted my attention to the mfd to see if we had indeed lost our anti ice capability; thinking that the autopilot had control of the aircraft. I only looked away for approximately 5 seconds which was just long enough to not notice that the autopilot was not initiating the turn back to the localizer course. The first thing I noticed when I looked back to the pfd was that the autopilot had not initiated the turn; and immediately forced the turn; but it is possible that we exceeded the 10 mile ring in the process.I don't have any constructive suggestions at this time. We ran all appropriate checklists; except for the failure of the autopilot to initiate the procedure turn inbound; we were able to comply with altitude and course requirements and successfully land the aircraft. I am writing this 20 hours after the event and maintenance has been working on the aircraft all night. The latest update is that they have not yet been able to fix it. I don't know that I'll ever know why the autopilot flew the course perfectly to the VOR; initiated the procedure turn outbound and then failed to initiate the procedure turn inbound.

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Original NASA ASRS Text

Title: CRJ700 Captain experienced an Anti Ice Duct warning during approach on an autopilot flown procedure turn outbound. The distraction of the duct fault prevents the crew from noting the autopilot has failed to commence the procedure turn inbound in a timely manor.

Narrative: While on the ILS DME; we were using FMS/GPS to navigate and the autopilot had just initiated the procedure turn outbound. We were beginning to accrete mixed ice and had just activated the wing anti-ice. Approximately 30 seconds later we received a Master Warning; ANTI ICE DUCT; followed by a Master Caution; ANTI ICE DUCT. The First Officer (pilot not flying) pulled out the FOM and I selected the Anti-Ice page on the MFD and noticed that the system had closed the bleed valves to the wings. I then looked back to the PFD and noticed that the aircraft has not initiated the procedure turn inbound and was still tracking on the outbound heading; so I placed the aircraft into the heading mode and began to turn it manually. We also initiated a decent to get out of icing conditions and to get to the authorized altitude for the inbound course. As the inbound course was coming alive; ATC asked if we were inside 10 miles of the IAF. We responded 'yes.' He said that he showed us at 12 miles. This is possible since the autopilot had not initiated the procedure turn inbound and it had taken me a few seconds to recognize that and initiate the turn manually. Nonetheless; when queried by ATC; we were well inside the 10 mile ring and have no recollection of passing the 10 mile ring from the IAF. At approximately 10;000 FT; we exited IMC and continued the ILS approach with no further incidents. This was the second maintenance write up for an ANTI ICE DUCT warning message in two days.This was one of those situations where everything happens at the same time. It started with a Master Warning that eliminated our anti ice capability as we were picking up moderate mixed ice. I diverted my attention to the MFD to see if we had indeed lost our anti ice capability; thinking that the autopilot had control of the aircraft. I only looked away for approximately 5 seconds which was just long enough to not notice that the autopilot was not initiating the turn back to the localizer course. The first thing I noticed when I looked back to the PFD was that the autopilot had not initiated the turn; and immediately forced the turn; but it is possible that we exceeded the 10 mile ring in the process.I don't have any constructive suggestions at this time. We ran all appropriate checklists; except for the failure of the autopilot to initiate the procedure turn inbound; we were able to comply with altitude and course requirements and successfully land the aircraft. I am writing this 20 hours after the event and Maintenance has been working on the aircraft all night. The latest update is that they have not yet been able to fix it. I don't know that I'll ever know why the autopilot flew the course perfectly to the VOR; initiated the procedure turn outbound and then failed to initiate the procedure turn inbound.

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.