As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKEOFF AT 1000 FT, CREW FELT A VERY PRONOUNCED THUMP ACCOMPANIED BY A LOUD NOISE. AUTO PACK TRIP ILLUMINATED. ENGINE INSTRUMENTS CHECKED NORMAL. WHILE TROUBLESHOOTING THE PROBLEM AND CLIMBING THROUGH 18,000FT. ANOTHER LOUD THUMP AND NOISE OCCURRED AND THE NR 1 ENGINE EPR DECREASED TO 1.5 EPR. RETARDED NR 1 THROTTLE RAN THE QRH CHECKLIST AND RETURNED TO PHL. FOUND APPROX 6 BLADES ON NR 1 ENGINE FAN DAMAGED CHECKING DAMAGE LIMITS.