Narrative:

We departed ZZZ at XA00 on jan/sun/04, after encountering 2 previous cancellations due to freezing drizzle and ice pellets. The aircraft was exposed to this WX on the ramp area for about 4 hours prior to our departure. The aircraft was covered with ice. We taxied out for departure during almost VFR conditions. ZZZ was 800 ft overcast, visibility 6 mi and mist. We requested a 'thorough' deicing with type 1 fluid and then departed. Upon entering IMC conditions, we turned on wing anti-ice. After flap retraction, we heard a loud bang or pop, followed by a heavy buzzing or vibration. We could not positively determine the nature of the problem, but suspected an engine malfunction. We declared an emergency and landed without further incident on runway 36R. After landing, we saw 3 heavily damaged fan blades in the #1 or left engine. We suspect that ice was still adhering to the aircraft or possibly inside the engine cowling and went undetected by the deicing crew. This ice dislodged in flight and was ingested. We don't know for sure since the engines are tail mounted and you can't see the bottom of the inlet during walkaround -- assuming of course the damage was from ice and not something else.

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Original NASA ASRS Text

Title: A CL65 IN CLB AT 3500 FT DECLARED AN EMER AND DIVERTED DUE TO L ENG FAN BLADE DAMAGE FROM ICE INGESTION.

Narrative: WE DEPARTED ZZZ AT XA00 ON JAN/SUN/04, AFTER ENCOUNTERING 2 PREVIOUS CANCELLATIONS DUE TO FREEZING DRIZZLE AND ICE PELLETS. THE ACFT WAS EXPOSED TO THIS WX ON THE RAMP AREA FOR ABOUT 4 HRS PRIOR TO OUR DEP. THE ACFT WAS COVERED WITH ICE. WE TAXIED OUT FOR DEP DURING ALMOST VFR CONDITIONS. ZZZ WAS 800 FT OVCST, VISIBILITY 6 MI AND MIST. WE REQUESTED A 'THOROUGH' DEICING WITH TYPE 1 FLUID AND THEN DEPARTED. UPON ENTERING IMC CONDITIONS, WE TURNED ON WING ANTI-ICE. AFTER FLAP RETRACTION, WE HEARD A LOUD BANG OR POP, FOLLOWED BY A HVY BUZZING OR VIBRATION. WE COULD NOT POSITIVELY DETERMINE THE NATURE OF THE PROB, BUT SUSPECTED AN ENG MALFUNCTION. WE DECLARED AN EMER AND LANDED WITHOUT FURTHER INCIDENT ON RWY 36R. AFTER LNDG, WE SAW 3 HEAVILY DAMAGED FAN BLADES IN THE #1 OR L ENG. WE SUSPECT THAT ICE WAS STILL ADHERING TO THE ACFT OR POSSIBLY INSIDE THE ENG COWLING AND WENT UNDETECTED BY THE DEICING CREW. THIS ICE DISLODGED IN FLT AND WAS INGESTED. WE DON'T KNOW FOR SURE SINCE THE ENGS ARE TAIL MOUNTED AND YOU CAN'T SEE THE BOTTOM OF THE INLET DURING WALKAROUND -- ASSUMING OF COURSE THE DAMAGE WAS FROM ICE AND NOT SOMETHING ELSE.

Data retrieved from NASA's ASRS site as of July 2007 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.