EMB ERJ 145 ER/LR
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Critical; Inflight Event / Encounter Weather / Turbulence
General Declared Emergency
Aircraft; Weather
During the descent; while in level flight in icing conditions at around FL180; an EICAS warning informed us that our wing anti ice system had failed. We did not immediately declare an emergency; but ran the appropriate QRH checklists and continued with our descent. While such EICAS messages are relatively common at low power settings; this one was unusual due to our relatively high power setting of roughly 86% N2. This struck us as odd and we took it as an indication of an actual system failure. We informed ATC of the situation; but still did not declare an emergency.Instead we opted to request an immediate descent out of known icing conditions. We were cleared down to 4;000 FT. After the Captain finished running the QRH; I briefed the approach to 22L with emphasis on the flap 22 landing with a Vref speed 30 KTS higher than usual as required by the emergency checklist. We informed ATC of our requirement for a faster approach than usual and requested greater spacing from the traffic in front of us. ATC turned us out wide and then through the localizer to give us that spacing. Just prior to turning on to the localizer; the Captain declared a precautionary emergency with ATC and requested emergency vehicles to meet us on the ground. He then briefed the Flight Attendant; who in turned briefed the passengers. I informed the Captain that due to the high speed approach and flaps 22 configuration; I would be using full reverse thrust and maximum braking upon landing. We landed the aircraft and exited the runway normally. Once we had checked the brake temperature we advised CFR could be released and we taxied in to the gate.
An E-145XR flight crew declared an emergency and landed safely following the failure of the wing anti-ice system in icing conditions.