What was found
AIRCRAFT NOT GROUNDED: PILOT REPORTS APPROX. 1500 FT AGL, A/C FULLY CONFIGURED FLAPS FULL 143 KNOTS, MEDIUM TO SEVERE VIBRATION IN RUDDER PEDALS. ON LDG FELT LIKE RUDDER MADE UNCOMMANDED MOVEMENT. NO FAULTS NOTED. PERFORMED RUDDER CONTROL ADJUSTMENTS AND TESTS IAW AMM 27-21-00, NO FAULTS FOUND. TESTED ARTIFICIAL FEEL AND RUDDER TRAVEL LIMITING-ACTIVATION IAW AMM 27-23-00, NO HISTORY. ALL CHECKS OK.