What was found
AS FLAPS EXTEND THROUGH 20 DEGREE AIRCRAFT BEGINS TO SHUTTER AND VIBRATES EXCESSIVELY. (FLT 4826) INSPECTED FLAPS ATTACHING HARDWARE, FAIRING GAPS, ALL ACCESS PANELS, GEAR DOORS AND GEAR, NO DEFECTS NOTED. CYCLED FLAPS SEVERAL TIMES WITH NO ABNORMAL NOISE OR VIBRATIONS IAW AMM.