What was found
ATW - FLT 309 - DURING EN ROUTE CLIMB WITH TMS TGT SYNC SELECTED, THE CPT AND FO FELT A PRONOUNCED AIRFRAME VIBRATION ON COCKPIT FLOOR AND COCKPIT SEATS. NO VIBRATION WAS FELT IN CONTROL YOKE. REMOVED AND REPLACED LOCKING PLATE ON RT WING MIDDLE SPOILER HINGE BOLT. (LOOSE BOLT CAUSED PLAY IN SPOILER HINGE.) OPS CHECK SATISFACTORY.