MD11 flight crew encounters icing resulting in fan blade damage to all 3 internal cowl surfaces.

Attributes
ACN	689255
Time
Date	200602
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : anc.airport
State Reference	AK
Altitude	msl single value : 5000
Environment
Flight Conditions	IMC
Weather Elements	Ice
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : a11.tracon
Operator	common carrier : air carrier
Make Model Name	MD-11
Operating Under FAR Part	Part 121
Flight Phase	climbout : intermediate altitude
Route In Use	departure : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : flight engineer pilot : cfi pilot : atp
Experience	flight time last 90 days : 125 flight time total : 14500 flight time type : 1800
ASRS Report	689255
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	inflight encounter : weather
Independent Detector	other flight crewa other flight crewb
Resolutory Action	none taken : anomaly accepted
Consequence	other
Supplementary
Problem Areas	Weather
Primary Problem	Weather

Narrative:

All preflight WX documentation indicated anc and fai WX would be well above required minimums at the estimated time of arrival and other WX related factors would not adversely affect the flight. Approximately 1 1/2 - 2 hours from anc; dispatch notified us by ACARS that our alternate; fai; was now below alternate minimums. Alternate was changed to eielson AFB. Approximately 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 approach; intermittent engine vibration monitoring system were activated. Engine icing was suspected so the RPM of all 3 engines was increased to increase ice dissipation. The first approach to runway 7L terminated in a tower initiated go around due to aircraft on the runway. After radar vectoring at 2000 ft MSL; a second approach terminated with a successful landing. Some snow was on the runway. Maintenance found evidence of fan blade icing damage to all 3 engine internal cowl surfaces. There were no reports of moderate or severe icing in the area.

Original NASA ASRS Text

Title: 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.

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.