Narrative:

Upon shutdown at gate in ZZZ, mechanic advised there was damage to several fan blades on #2 engine. We had flown the same plane the night before. Departure airport WX: low ovc, low visibility, fzfg, -8C. Arrival airport WX: 3500 ovc, good visibility, 8C. After pushback and starting both engines (thermal anti ice on) taxied to deice pad. Deiced type I fluid. During deice a mild vibration was felt on #2 engine. Vibration ceased on taxi to runway. Performed 1ST run up on runway 34 (70%, 30 second) as 30 min hadn't yet elapsed. No vibration felt but #2 vib ind showed high vib. After 30 second idle selected. After pause, another run up performed. No vib felt and #2 ind moved to less than 2. We concluded ice shed and takeoff was safe. Takeoff uneventful with thermal anti ice and wing anti ice used in climb to 9800 ft MSL. Later thermal anti ice and wing anti ice used per SOP. Some rime observed on wiper nut. Engine ind normal. Trip uneventful. No damage observed on walk around in ZZZ1. Climb, cruise and descent normal. Thermal anti ice used on approach to ZZZ thru thin layer and until shutdown. Upon shutdown, amt advised and I observed varying damage to 8 fan blades (bent) at varying locations on the circumference of fan face. Plane taken out of service for repair. Callback conversation with reporter revealed the following information: the reporter stated the airplane was deiced prior to the flight into ZZZ and both engines and landing gear were deiced on the gate then after pushback was taxied to a deicing area for airframe deicing. The reporter stated on termination of the flight #2 engine was found to have fan blade tip damage. The reporter stated no vibration was indicated or detected in flight and the #2 engine operated normally. The reporter said he has no idea how the ice could form after deicing and only damage #2 engine. The reporter stated could it be possible to form ice on one engine while taxiing with a prevailing wind blowing on #2 engine?

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Original NASA ASRS Text

Title: B737-300 CREW HAD ENG FAN BLADES THAT WERE DAMAGED.

Narrative: UPON SHUTDOWN AT GATE IN ZZZ, MECH ADVISED THERE WAS DAMAGE TO SEVERAL FAN BLADES ON #2 ENG. WE HAD FLOWN THE SAME PLANE THE NIGHT BEFORE. DEP ARPT WX: LOW OVC, LOW VIS, FZFG, -8C. ARR ARPT WX: 3500 OVC, GOOD VIS, 8C. AFTER PUSHBACK AND STARTING BOTH ENGS (THERMAL ANTI ICE ON) TAXIED TO DEICE PAD. DEICED TYPE I FLUID. DURING DEICE A MILD VIBRATION WAS FELT ON #2 ENG. VIBRATION CEASED ON TAXI TO RWY. PERFORMED 1ST RUN UP ON RWY 34 (70%, 30 SEC) AS 30 MIN HADN'T YET ELAPSED. NO VIBRATION FELT BUT #2 VIB IND SHOWED HIGH VIB. AFTER 30 SEC IDLE SELECTED. AFTER PAUSE, ANOTHER RUN UP PERFORMED. NO VIB FELT AND #2 IND MOVED TO LESS THAN 2. WE CONCLUDED ICE SHED AND TKOF WAS SAFE. TKOF UNEVENTFUL WITH THERMAL ANTI ICE AND WING ANTI ICE USED IN CLB TO 9800 FT MSL. LATER THERMAL ANTI ICE AND WING ANTI ICE USED PER SOP. SOME RIME OBSERVED ON WIPER NUT. ENG IND NORMAL. TRIP UNEVENTFUL. NO DAMAGE OBSERVED ON WALK AROUND IN ZZZ1. CLB, CRUISE AND DSCNT NORMAL. THERMAL ANTI ICE USED ON APCH TO ZZZ THRU THIN LAYER AND UNTIL SHUTDOWN. UPON SHUTDOWN, AMT ADVISED AND I OBSERVED VARYING DAMAGE TO 8 FAN BLADES (BENT) AT VARYING LOCATIONS ON THE CIRCUMFERENCE OF FAN FACE. PLANE TAKEN OUT OF SVC FOR REPAIR. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE AIRPLANE WAS DEICED PRIOR TO THE FLT INTO ZZZ AND BOTH ENGS AND LNDG GEAR WERE DEICED ON THE GATE THEN AFTER PUSHBACK WAS TAXIED TO A DEICING AREA FOR AIRFRAME DEICING. THE RPTR STATED ON TERMINATION OF THE FLT #2 ENG WAS FOUND TO HAVE FAN BLADE TIP DAMAGE. THE RPTR STATED NO VIBRATION WAS INDICATED OR DETECTED IN FLT AND THE #2 ENG OPERATED NORMALLY. THE RPTR SAID HE HAS NO IDEA HOW THE ICE COULD FORM AFTER DEICING AND ONLY DAMAGE #2 ENG. THE RPTR STATED COULD IT BE POSSIBLE TO FORM ICE ON ONE ENG WHILE TAXIING WITH A PREVAILING WIND BLOWING ON #2 ENG?

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.