MD11 FLT CREW ENCOUNTERS ICING RESULTING IN FAN BLADE DAMAGE TO ALL 3 INTERNAL COWL SURFACES.

Narrative

ALL PREFLT WX DOCUMENTATION INDICATED ANC AND FAI WX WOULD BE WELL ABOVE REQUIRED MINIMUMS AT THE ESTIMATED TIME OF ARR AND OTHER WX RELATED FACTORS WOULD NOT ADVERSELY AFFECT THE FLT. APPROX 1 1/2 - 2 HRS FROM ANC; DISPATCH NOTIFIED US BY ACARS THAT OUR ALTERNATE; FAI; WAS NOW BELOW ALTERNATE MINIMUMS. ALTERNATE WAS CHANGED TO EIELSON AFB. APPROX 30 MINS LATER; DISPATCH NOTIFIED US THAT EIELSON AFB WAS NOW ALSO BELOW ALTERNATE MINIMUMS AND NO OTHER SUITABLE ALTERNATES EXISTED. ANC WX REMAINED ABOVE CAT I MINIMUMS. DURING APCH; INTERMITTENT ENG VIBRATION MONITORING SYS WERE ACTIVATED. ENG ICING WAS SUSPECTED SO THE RPM OF ALL 3 ENGS WAS INCREASED TO INCREASE ICE DISSIPATION. THE FIRST APCH TO RWY 7L TERMINATED IN A TWR INITIATED GAR DUE TO ACFT ON THE RWY. AFTER RADAR VECTORING AT 2000 FT MSL; A SECOND APCH TERMINATED WITH A SUCCESSFUL LNDG. SOME SNOW WAS ON THE RWY. MAINT FOUND EVIDENCE OF FAN BLADE ICING DAMAGE TO ALL 3 ENG INTERNAL COWL SURFACES. THERE WERE NO RPTS OF MODERATE OR SEVERE ICING IN THE AREA.