A B757-200 on rotation struck a flock of large birds incur fan blade damage.

Attributes
ACN	555364
Time
Date	200207
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : sfo.airport
State Reference	CA
Altitude	agl single value : 0
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B757 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	ground : takeoff roll
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	555364
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
ASRS Report	555171
Events
Anomaly	aircraft equipment problem : critical inflight encounter : birds
Independent Detector	other flight crewa other flight crewb
Resolutory Action	flight crew : overcame equipment problem flight crew : returned to intended or assigned course
Consequence	other other other
Supplementary
Problem Areas	Flight Crew Human Performance Aircraft Maintenance Human Performance
Primary Problem	Aircraft

Narrative:

Taking off on runway 1L, at rotation a flock of birds were encountered which we could not avoid. Estimated size of flock was 40-50 large size birds. We could hear numerous thumps and thuds and immediately smelled burning fowl. I thought we would have a problem with either one of the engines, but they continued to operate normally. We continued the climb and leveled off at 5000 ft. We assessed the engine's condition which appeared normal. We contacted dispatch and maintenance and I relayed the information to them. All indications being normal. The airplane was operating normal so we decided to continue on to ZZZ1. We told the flight attendants of the situation. There were 2 deadheading pilots on board and they assessed the co-invitation of the engine, being normal. I informed the passenger that we would continue on to ZZZ1. We cruised at FL210 and the remainder of the flight was normal. Upon inspection of the aircraft we found at least 8 different impact points on the aircraft. Both engines showed damage to the fan blades.

Original NASA ASRS Text

Title: A B757-200 ON ROTATION STRUCK A FLOCK OF LARGE BIRDS INCUR FAN BLADE DAMAGE.

Narrative: TAKING OFF ON RWY 1L, AT ROTATION A FLOCK OF BIRDS WERE ENCOUNTERED WHICH WE COULD NOT AVOID. ESTIMATED SIZE OF FLOCK WAS 40-50 LARGE SIZE BIRDS. WE COULD HEAR NUMEROUS THUMPS AND THUDS AND IMMEDIATELY SMELLED BURNING FOWL. I THOUGHT WE WOULD HAVE A PROB WITH EITHER ONE OF THE ENGS, BUT THEY CONTINUED TO OPERATE NORMALLY. WE CONTINUED THE CLB AND LEVELED OFF AT 5000 FT. WE ASSESSED THE ENG'S CONDITION WHICH APPEARED NORMAL. WE CONTACTED DISPATCH AND MAINT AND I RELAYED THE INFO TO THEM. ALL INDICATIONS BEING NORMAL. THE AIRPLANE WAS OPERATING NORMAL SO WE DECIDED TO CONTINUE ON TO ZZZ1. WE TOLD THE FLT ATTENDANTS OF THE SIT. THERE WERE 2 DEADHEADING PLTS ON BOARD AND THEY ASSESSED THE CO-INVITATION OF THE ENG, BEING NORMAL. I INFORMED THE PAX THAT WE WOULD CONTINUE ON TO ZZZ1. WE CRUISED AT FL210 AND THE REMAINDER OF THE FLT WAS NORMAL. UPON INSPECTION OF THE ACFT WE FOUND AT LEAST 8 DIFFERENT IMPACT POINTS ON THE ACFT. BOTH ENGS SHOWED DAMAGE TO THE FAN BLADES.

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.