Narrative:

During the climb we went through several layers of clouds and followed the proper procedure for anti-ice; in fact the anti-ice was turned on well before the definition of 'icing conditions.' still into the climb from FL250 to cruise of FL270; we encountered another layer of icing conditions. Wing/cowl anti-ice on due to ice message it seemed like light-moderate ice forming on the windshield wipers. After 3-5 mins the right engine vib amber ring came up with the N1 vib going from 3.3-3.5. I requested that the first officer declare an emergency. I turned the autoplt off; then asked the first officer to have the flight attendant be seated and put the aircraft into a descent to FL240. I asked the first officer to perform the QRH for an N1 fan vib. After leveling off and out of icing conditions the problem still existed. I realized the first officer read the wrong QRH procedure; N2 core. I put the aircraft autoplt on in order to rectify the situation and then read the right QRH procedure; N1 fan vib. It took the engine from 5-6 mins to clear. I had the feeling that the cowl anti-ice on that engine was not working correctly. ATC asked us if we would like to divert to ZZZ and I asked if they could stand by. I called dispatch and also spoke with maintenance. The WX in ZZZ had several layers of visible moisture. I received the WX for ZZZ1 and ZZZ2 and flying east was the best option. The engine indications were all normal; therefore we decided to continue eastbound to stay clear of icing conditions. A maintenance write-up was put in the logbook upon arrival.

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Original NASA ASRS Text

Title: CRJ200 FLT CREW REPORTS FAN VIBRATION AT FL270 WHILE FLYING IN ICING CONDITIONS WITH ENGINE ANTI-ICE ON. VIBRATION EVENTUALLY SUBSIDES AT FL240.

Narrative: DURING THE CLB WE WENT THROUGH SEVERAL LAYERS OF CLOUDS AND FOLLOWED THE PROPER PROC FOR ANTI-ICE; IN FACT THE ANTI-ICE WAS TURNED ON WELL BEFORE THE DEFINITION OF 'ICING CONDITIONS.' STILL INTO THE CLB FROM FL250 TO CRUISE OF FL270; WE ENCOUNTERED ANOTHER LAYER OF ICING CONDITIONS. WING/COWL ANTI-ICE ON DUE TO ICE MESSAGE IT SEEMED LIKE LIGHT-MODERATE ICE FORMING ON THE WINDSHIELD WIPERS. AFTER 3-5 MINS THE R ENG VIB AMBER RING CAME UP WITH THE N1 VIB GOING FROM 3.3-3.5. I REQUESTED THAT THE FO DECLARE AN EMER. I TURNED THE AUTOPLT OFF; THEN ASKED THE FO TO HAVE THE FLT ATTENDANT BE SEATED AND PUT THE ACFT INTO A DSCNT TO FL240. I ASKED THE FO TO PERFORM THE QRH FOR AN N1 FAN VIB. AFTER LEVELING OFF AND OUT OF ICING CONDITIONS THE PROB STILL EXISTED. I REALIZED THE FO READ THE WRONG QRH PROC; N2 CORE. I PUT THE ACFT AUTOPLT ON IN ORDER TO RECTIFY THE SITUATION AND THEN READ THE RIGHT QRH PROC; N1 FAN VIB. IT TOOK THE ENG FROM 5-6 MINS TO CLR. I HAD THE FEELING THAT THE COWL ANTI-ICE ON THAT ENG WAS NOT WORKING CORRECTLY. ATC ASKED US IF WE WOULD LIKE TO DIVERT TO ZZZ AND I ASKED IF THEY COULD STAND BY. I CALLED DISPATCH AND ALSO SPOKE WITH MAINT. THE WX IN ZZZ HAD SEVERAL LAYERS OF VISIBLE MOISTURE. I RECEIVED THE WX FOR ZZZ1 AND ZZZ2 AND FLYING E WAS THE BEST OPTION. THE ENG INDICATIONS WERE ALL NORMAL; THEREFORE WE DECIDED TO CONTINUE EBOUND TO STAY CLR OF ICING CONDITIONS. A MAINT WRITE-UP WAS PUT IN THE LOGBOOK UPON ARR.

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.