As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RETURNED TO ORD DUE TO A SLIGHT VIBRATION. VISUALLY CHECKED NR 1 ENGINE AND FOUND EVIDENCE OF BIRDSTRIKE IN THE ENGINE INLET. ACCOMPLISHED A BIRDSTRIKE INSPECTION AND BORESCOPE ON THE ENGINE. FOUND TWO FAN BLADES BENT BEYOND LIMITS WITH NO OTHER DISCREPANCIES OR EVIDENCE OF FURTHER BIRD INGESTION INTO THE ENGINE. CLEANED BIRSTRIKE DEBRIS FROM THE ENGINE INLET AND REPLACED BENT FAN BLADES (2 PAIRS).