A B767 STRUCK A BIRD ON TKOF DAMAGING AN ENG. THE ACFT RETURNED TO LAND WITH FAN BLADE DAMAGE.

Narrative

ON TKOF ROLL OUT OF ZZZ RWY 25 AT APPROX 100 KTS; WE SAW A BIRD GO UNDER THE NOSE AND HEARD A BANG LIKE IT HIT THE ACFT BUT WE WEREN'T SURE WHERE. AFTER TKOF WE FELT SOME VIBRATION AND HEARD THE L ENG LOUDER THAN NORMAL. WE NOTICED THAT L ENG N1 VIB WAS AT 5.0 WHILE R ENG WAS BELOW 1.0. ALL OTHER INDICATIONS LOOKED NORMAL ON BOTH ENGS. WE LEVELED OFF AT 10000 FT MSL AND WHEN THE PWR CAME BACK; THE VIBRATION STOPPED AND N1 VIB ALSO WAS NORMAL. HOWEVER; WHEN WE STARTED A CLB TO 15000 FT MSL; THE VIBRATION RETURNED AND THE INDICATION WAS ABOUT 4.7. AT THIS TIME THE FLT ATTENDANTS AT 1L AND 2L CALLED TO TELL US ABOUT THE VIBRATION. WE THEN REDUCED THE PWR IN THE CLB TO KEEP VIBRATIONS DOWN AND CONTINUED UP TO FL190 SINCE WE WERE APCHING HIGH TERRAIN AND WE WERE IN AND OUT OF WX DUE TO TSTM IN THE FOOTHILLS. WE INITIATED A CALL TO MAINT AND DID A LITTLE TROUBLESHOOTING BASICALLY FIGURING THAT A BIRD HAD PROBABLY BEEN INGESTED IN THE L ENG AND WAS CAUSING THE VIBRATION. ANYTIME WE ADVANCED THE THROTTLE TOWARDS CLB PWR THE INDICATIONS RETURNED SO WE ELECTED TO RETURN TO ZZZ. WE LEFT THE ENG AT LOWER PWR SO THERE WAS NO REAL PROB WITH ANY MORE VIB. WE ELECTED TO LEAVE THE ENG RUNNING AND DID NOT DECLARE AN EMER. ZZZ CTL VECTORED US IN FAIRLY QUICKLY AND WE LANDED UNEVENTFULLY. NICE JOB BY EVERYONE. LOOKED AT THE ENG AFTER LNDG AND SAW 2 BLADES BENT BUT NO BIRD REMAINS.