As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
VIBRATIONS FELT IN CONTROL COLUMN & FLOOR & HEARD AT FL 280 DOWN TO 7000 FT. NO CHANGE WITH AUTOPILOT OFF. REPEAT GRIPE. R & R RT AFT OTBD ELEVATOR CONTROL CABLE IAW AMM 27-31-01. R & R RT ELEVATOR TENSION REGULATOR IAW AMM 27-31-01. SEE NRWCS 645-ABI-02120 & 645-ABI-02121 FOR ADDITIONAL DETAILS & BILLING.