As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PHL EN ROUTE PHL-ORD VIBRATIONS AND LOUD NOISE COMING FROM NOSE GEAR AREA. RETURNED PHL AND LANDED WITHOUT INCIDENT. FOUND NOSE GEAR DOORS DOWN AND OPEN. INSPECTED NOSE GEAR DOORS AND NO DAMAGE FOUND. CLOSED DOORS AND RE-DEPARTED. SYSTEM GROUND CHECKED NORMAL OPERATION.