What was found
AIRCRAFT WAS GROUNDED: AN EMERGENCY WAS DECLARED AND THE AIRCRAFT RETURNED TO DFW DUE TO THE FLIGHT CREW REPORTING ON CLIMBOUT OF DFW AT 250 KNOTS THEY ENCOUNTERED AIRFRAME AND RUDDER VIBRATION WHICH COULD BE FELT IN THE BACK CABIN AND THE RUDDER PEDDALS - THE FLIGHT CREW REORTED THE VIBRATION WAS MORE NOTICEABLE IN TURNS AND AT HIGHER SPEEDS - THE FLIGHT CREW REPORTED THAT THE TRIM VALUES WERE NORMAL AND NO ABNORMAL INDICATIONS WERE NOTED - THE AIRCRAFT LANDED SAFLEY AT DFW AND TAXIED TO THE GATE UNDER ITS OWN POWER. (OPEN)