As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
EN ROUTE IAD-FRA, PRONOUNCED VIBRATION IN FLOOR AT DOOR 2R. VIBRATION WORSE IN CLIMB, DIMINISHED AT LEVEL OFF. AIRCRAFT RETURNED TO FIELD. *S/D* MAINTENANCE CHECKED AIR CONDITIONING RAM AIR DOORS AND FOUND CONDITION ACCEPTABLE. ALSO ENGINEERING CALLED FOR CHECK OF SLAT EXTENSION ARM DOOR AND FOUND NO DISCREPANCIES. AIRCRAFT RETURNED TO SERVICE WITH NOT FURTHER WRITE-UPS.