What was found
UPON GEAR RETRACTION EXTREMELY LOUD VIBRATION & AIR NOISE IN COCKPIT FLOOR & A ZONE GALLEY. SPEED NEVER ABOVE 250 KNOTS DUMPED 50,000 LBS FUEL & RETURNED. IAW NR`S 4916081, 4916090, 4916093, 4916086, 4916089, 4916100 & 4916094 ACFT OK FOR SERVICE. RT AFT NOSE GEAR DOOR REPLACED.