What was found
AIR TURN BACK DUE TO SEVERE AIRFRAME VIBRATION. BEGAN AT 25,500 FT AND AROUND 330 KIAS. DID NOT STOP UNTIL SPEED MANUALLY FLOWN LESS THAN 300 KIAS. EMERGENY DECLARED. R & R LT AND RT ELEVATOR ATTACH HARDWARE AND BEARINGS REF AMM 27-34-41, PAGE BLOCK 401. R & R LT AND RT ELEVATOR A FRAME BEARINGS REF AMM 55-16-42, PAGE BLOCK 401. ADJUSTED LT AND RT ELEVATORS TO 0.5 DEGRESS NOSE UP. REF AMM 27-34-00-820-003-B01, NON-ROUTINE 110308.