Narrative:

We were on approach when we received a left wing anti ice; we were not accreting ice and I asked the first officer (pm) to run the QRH. We let ATC know that we had an issue and continued on the localizer at 5;000 feet with the hope that the QRH would resolve our issue. Before this was complete; however; we began to accrete ice and I decided to go missed and climb to 7;000 feet where we knew there was no ice. ATC was very busy on the radio and we could not transmit our intentions. I noted that in addition to the ice detection advisory message; the wipers were rapidly accreting moderate mixed ice. I exercised emergency authority to initiate the climb with the intention of contacting ATC when the frequency was not blocked. My great concern was a rapid buildup of ice on one wing; creating an asymmetrical roll moment which could be unrecoverable. We had climbed about 500 feet when we got through to ATC but at that time we were already out of icing conditions; and the a/I (anti-ice) caution disappeared. We still asked for and received 7;000 feet with the intention of evaluating our situation; checking alternate weather; texting the dispatcher and notifying the fas of the reason for our extended approach duration. We tried the approach again with the plan that should we lose the anti-ice again we would expedite our descent to 3;000 feet MSL where we knew there was clear air and no icing. During this 2nd approach the autopilot disconnected on its own; but it was not likely associated with ice and was not out of trim. However as a precaution I hand flew the remainder of the flight. The left wing a/I caution briefly came back but not during icing accretion. ATC offered a quick descent to 3;000 feet rather than riding the glideslope which we accepted. We landed normally.this aircraft has a history of left wing a/I and autopilot disconnect; however not at the same time and probably not related. I expressed to the mechanics the importance of resolving this issue before another flight into icing conditions; and they agreed. As to ATC; they were very busy and possibly doing training and I think it may have been better for me to transmit a mayday over the other pilots and ATC and hope they heard; or have my first officer squawk 7700 to ensure that our climb would be immediately noticed. As it turned out our emergency was immediately resolved by leaving icing conditions and the return of our anti-ice; and then ATC gave us exactly what we wanted as a precaution. Another point is that I could have asked for a climb immediately after the caution came on since I knew 7;000 feet would be good; and 5;000 feet would possibly have ice. In that way we could have utilized an available time on the radio to communicate and then resolve our issue.

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Original NASA ASRS Text

Title: CRJ-700 flight crew reported that on approach they received a 'L WING ANTI ICE'; they were not accumulating ice. The autopilot tripped off during the same event.

Narrative: We were on approach when we received a L WING ANTI ICE; we were not accreting ice and I asked the FO (PM) to run the QRH. We let ATC know that we had an issue and continued on the localizer at 5;000 feet with the hope that the QRH would resolve our issue. Before this was complete; however; we began to accrete ice and I decided to go missed and climb to 7;000 feet where we knew there was no ice. ATC was very busy on the radio and we could not transmit our intentions. I noted that in addition to the ice detection advisory message; the wipers were rapidly accreting moderate mixed ice. I exercised emergency authority to initiate the climb with the intention of contacting ATC when the frequency was not blocked. My great concern was a rapid buildup of ice on one wing; creating an asymmetrical roll moment which could be unrecoverable. We had climbed about 500 feet when we got through to ATC but at that time we were already out of icing conditions; and the A/I (anti-ice) caution disappeared. We still asked for and received 7;000 feet with the intention of evaluating our situation; checking alternate weather; texting the dispatcher and notifying the FAs of the reason for our extended approach duration. We tried the approach again with the plan that should we lose the anti-ice again we would expedite our descent to 3;000 feet MSL where we knew there was clear air and no icing. During this 2nd approach the autopilot disconnected on its own; but it was not likely associated with ice and was not out of trim. However as a precaution I hand flew the remainder of the flight. The L WING A/I caution briefly came back but not during icing accretion. ATC offered a quick descent to 3;000 feet rather than riding the glideslope which we accepted. We landed normally.This aircraft has a history of L WING A/I and autopilot disconnect; however not at the same time and probably not related. I expressed to the mechanics the importance of resolving this issue before another flight into icing conditions; and they agreed. As to ATC; they were very busy and possibly doing training and I think it may have been better for me to transmit a MAYDAY over the other pilots and ATC and hope they heard; or have my FO squawk 7700 to ensure that our climb would be immediately noticed. As it turned out our emergency was immediately resolved by leaving icing conditions and the return of our anti-ice; and then ATC gave us exactly what we wanted as a precaution. Another point is that I could have asked for a climb immediately after the caution came on since I knew 7;000 feet would be good; and 5;000 feet would possibly have ice. In that way we could have utilized an available time on the radio to communicate and then resolve our issue.

Data retrieved from NASA's ASRS site 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.