Narrative:

While at FL320 about 1 hour into the flight we heard a muffled bang and heard and felt a slight airframe vibration. We were in clear air and icing conditions did not exist at or near the time of the event. The right engine fan vibration gauge indicated amber dashed lines. The other right engine indications were steady within their normal range. If the engine had a marked rise in itt then I would have run the 'engine fire or severe engine damage in flight' procedure. Instead; we ran the QRH procedure for 'N1 fan vibration.' when we retarded the right engine thrust lever to idle; the right engine fan vibe indicated 3.0. This was the lowest fan vibe indication that we could achieve. We continued with the 'single engine procedures.' while we ran this procedure we declared an emergency and received vectors to ZZZ. After completion of the 'single engine procedure' we completed the 'single engine approach and landing procedure.' I contacted flight attendant and told her that we had to shut down the right engine due to a fan vibration. I advised that we were diverting to ZZZ; and we would make a normal landing in about 10 mins. Next in a PA to the passenger I advised them that we had to shut down the right engine due to a vibration. I told them that our other engine was working fine; and we would be making a normal landing in ZZZ in less than 10 mins. I advised them that they would see fire trucks along the runway when we land; and that this was just a precaution because we would have a slightly faster approach speed. I contacted dispatch and advised them about the engine shutdown. Our dispatcher agreed that ZZZ was a suitable diversionary airport and he calculated our landing field length requirements. We completed the remainder of the normal checklists. We completed a single engine approach and landing without incident. Landing weight was about 46400 pounds. After arrival at the gate we deplaned the passenger. Postflt inspection found damage to tips of the right engine fan blades. The mechanic who met the flight was instructed by maintenance control to inspect the galley potable water system and drain. He found that there was a slow leak in the galley water system. When I questioned the flight attendant she stated that she noticed that the galley water system was indicating low when we were on approach to ZZZ. Unless there is a stress crack failure found in the right engine fan blades; it is my belief that the engine damage was caused by ice which must have formed around the galley drain mast and flew through the right engine while at cruise flight.

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Original NASA ASRS Text

Title: CRJ200 FLT CREW REPORTS N1 VIBRATION AT FL320 AFTER MUFFLED BANG. N1 VIB GAUGE IS NOTED OFF SCALE HIGH AND ENGINE IS SHUT WITH DIVERSION TO NEAREST SUITABLE ARPT.

Narrative: WHILE AT FL320 ABOUT 1 HR INTO THE FLT WE HEARD A MUFFLED BANG AND HEARD AND FELT A SLIGHT AIRFRAME VIBRATION. WE WERE IN CLR AIR AND ICING CONDITIONS DID NOT EXIST AT OR NEAR THE TIME OF THE EVENT. THE R ENG FAN VIBRATION GAUGE INDICATED AMBER DASHED LINES. THE OTHER R ENG INDICATIONS WERE STEADY WITHIN THEIR NORMAL RANGE. IF THE ENG HAD A MARKED RISE IN ITT THEN I WOULD HAVE RUN THE 'ENG FIRE OR SEVERE ENG DAMAGE IN FLT' PROC. INSTEAD; WE RAN THE QRH PROC FOR 'N1 FAN VIBRATION.' WHEN WE RETARDED THE R ENG THRUST LEVER TO IDLE; THE R ENG FAN VIBE INDICATED 3.0. THIS WAS THE LOWEST FAN VIBE INDICATION THAT WE COULD ACHIEVE. WE CONTINUED WITH THE 'SINGLE ENG PROCS.' WHILE WE RAN THIS PROC WE DECLARED AN EMER AND RECEIVED VECTORS TO ZZZ. AFTER COMPLETION OF THE 'SINGLE ENG PROC' WE COMPLETED THE 'SINGLE ENG APCH AND LNDG PROC.' I CONTACTED FLT ATTENDANT AND TOLD HER THAT WE HAD TO SHUT DOWN THE R ENG DUE TO A FAN VIBRATION. I ADVISED THAT WE WERE DIVERTING TO ZZZ; AND WE WOULD MAKE A NORMAL LNDG IN ABOUT 10 MINS. NEXT IN A PA TO THE PAX I ADVISED THEM THAT WE HAD TO SHUT DOWN THE R ENG DUE TO A VIBRATION. I TOLD THEM THAT OUR OTHER ENG WAS WORKING FINE; AND WE WOULD BE MAKING A NORMAL LNDG IN ZZZ IN LESS THAN 10 MINS. I ADVISED THEM THAT THEY WOULD SEE FIRE TRUCKS ALONG THE RWY WHEN WE LAND; AND THAT THIS WAS JUST A PRECAUTION BECAUSE WE WOULD HAVE A SLIGHTLY FASTER APCH SPD. I CONTACTED DISPATCH AND ADVISED THEM ABOUT THE ENG SHUTDOWN. OUR DISPATCHER AGREED THAT ZZZ WAS A SUITABLE DIVERSIONARY ARPT AND HE CALCULATED OUR LNDG FIELD LENGTH REQUIREMENTS. WE COMPLETED THE REMAINDER OF THE NORMAL CHKLISTS. WE COMPLETED A SINGLE ENG APCH AND LNDG WITHOUT INCIDENT. LNDG WT WAS ABOUT 46400 LBS. AFTER ARR AT THE GATE WE DEPLANED THE PAX. POSTFLT INSPECTION FOUND DAMAGE TO TIPS OF THE R ENG FAN BLADES. THE MECH WHO MET THE FLT WAS INSTRUCTED BY MAINT CTL TO INSPECT THE GALLEY POTABLE WATER SYS AND DRAIN. HE FOUND THAT THERE WAS A SLOW LEAK IN THE GALLEY WATER SYS. WHEN I QUESTIONED THE FLT ATTENDANT SHE STATED THAT SHE NOTICED THAT THE GALLEY WATER SYS WAS INDICATING LOW WHEN WE WERE ON APCH TO ZZZ. UNLESS THERE IS A STRESS CRACK FAILURE FOUND IN THE R ENG FAN BLADES; IT IS MY BELIEF THAT THE ENG DAMAGE WAS CAUSED BY ICE WHICH MUST HAVE FORMED AROUND THE GALLEY DRAIN MAST AND FLEW THROUGH THE R ENG WHILE AT CRUISE FLT.

Data retrieved from NASA's ASRS site as of May 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.