What was found
FLIGHT CREW REPORTED A LOUD VIBRATION WAS HEARD UPON FLAP EXTENSION ON APPROACH THAT APPEARED TO BE COMING FROM RT SIDE OF AIRCRAFT. PERFORMED INSPECTION PER MM 05-51-67, NO ABNORMALITIES OR DISCREPANCIES NOTED. PERFORMED TEST FLIGHT. TEST FLIGHT UNSATISFACTORY DUE TO VIBRATION AT FLAP SETTINGS 10-30. FOUND RT INBOARD AFT FLAP DEAD WEIGHT ROLLERS OUT OF RIG. ADJUSTED DEAD WEIGHT ROLLERS PER MM 27-51-11 AND FLAP OPS CHECKED GOOD. PERFORMED ANOTHER TEST FLIGHT, WITH NO DISCREPANCIES NOTED.