What was found
SEVERE ACFT VIBRATION FELT AT FL 290 WITH A SPEED OF APROX 290 KTS & THROUGHOUT 260 KTS VIBRATION STOPPED. IAW TSM 05-50-00-810-801-A IDENTIFICATION OF THE CAUSE OF INFLIGHT AIRFRAME VIBRATIONS & OR NOISES WAS ACCOMPLISHED IAW TSM TASK 27-30-00-810-850-A. AIRFRAME VIBRATION DUE TO THE ELEVATOR WAS ACCOMPLISHED. IAW AMM TASK 27-34-00-200-001-A, CHECK OF THE ELEVATOR SERVO CONTROLS & HINGE BEARINGS FOR EXCESSIVE PLAY & CONDITION WAS ACCOMPLISHED. IAW AMM TASK 55-16-42-000-001 & 55-16-42-400-001-A THE HINGE ARM END FITTINGS 1 - 6 ON LT ELEVATOR WERE REPLACED & OPERATIONAL TEST WAS SATISFACTORY.