What was found
EXTREAMLY STRONG VIBRATION INFLIGHT FELT THROUGH WHOLE AIRCRAFT AT FL 190-230-PERFORMED OPS TEST OF ELEVATOR DAMPING IAW AMM 27-9600-710-008-A TEST OK PERFORMED VISUAL INSPECTION OF FUSELAGE IAW AMM 05-21-00,05-22-00,05-23-00 NO DEFECTS NOTED.