What was found
ON TAKEOFF ABOVE 1000' WE HAD A BIRDSTRIKE ON THE #1 ENGINE. LP VIBRATION WAS NOTED AT 4.1 OR HIGHER. NOTICABLE VIBRATION AND SOUND. FOUND DAMAGE TO MULTIPLE #1 FAN BLADES WITH EVIDENCE OF A BIRD STRIKE IN THE NACELLE & ON THE FLAP BEHIND MLG #1 SIDE. VIBRATION NORMAL BELOW 50% N1. DECLARED EMERGENCY. RETURNED TO FIELD. LANDING UNEVENTFUL. REMOVED FROM SERVICE. PERFORMED BIRDSTRIKE INSPECTION ON AIRCRAFT AND REMOVED BIRD REMAINS IAW E175 AMM 05-50-02-200-801-A. NO EVIDENCE OF #1 ENGINE CORE INGESTION. FOUND DAMAGE TO #1 ENGINE FAN BLADES #23, 27, 28, 1, 2, 3 AND 4. REMOVED AND REPLACED #1 ENG FAN BLADE & PIN SET (REF T/C E175-72-00-00-QE03). VIBE CHECK GOOD, NFDN. RETURNED TO SERVICE.