What was found
FLT#1731, SLC- LAX. (AIRCRAFT PERFORMED AN AIR TURN BACK TO SLC) ' BIRD STRIKE ON TAKEOFF APPROX 20 KTS PRIOR TO V1 (APPROX 130 KTS) HEARD LOUD THUMP ON RT SIDE WITH VIBRATION ALL ENGINE PARAMETERS NORMAL AIR RETURN TO SLC; PERFORMED BIRDSTRIKE INSPECTION 05-51-14 AND 05-51-19. REF DEFECTS 40229369 THROUGH 4022944 (REPLACED ENG 2 FAN BLADE 16 REF AMM 72-31-11 SEE DEFECT 4022942-2 (PERFORMED ONE SHOT FAN TRIM BALANCE REF AMM 71-00-00-700-012-B TEST 9. VIBES WITHIN LIMITS ) FOR TRIM BALANCING AND REPLACED ENG 2 FAN BLADE 15 REF AMM 72-31-11 SEE DEFECT 4022942-2 (PERFORMED ONE SHOT FAN TRIM BALANCE REF AMM 71-00-00-700-012-B TEST 9. VIBES WITHIN LIMITS ) FOR TRIM BALANCING) FOR FINDINGS AND RESOLUTION.'