As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING FLIGHT, THE RT TR DEPLOYED AT FL 100. CREW FELT YAWING AND VIBRATION SIMILAR TO SPEED BRAKE DEPLOYMENT. CREW COMPLETED THE CHECKLIST ITEMS, INCLUDING SHUTTING DOWN THE RAT ENGINE. CREW DECLARED AN EMERGENCY AND RETURNED TO. TRY HAD BEEN PINNED AND MELD PRIOR TO FLIGHT. MAINTENANCE DISCOVERED THE BIG OVER-CENTER LINKS ON THE RAT TRY WERE NOT OVER-CENTER AND THE TRY HAD PARTIALLY DEPLOYED. THE TRY WAS FOUND TO HAVE BEEN PINNED CORRECTLY YAW THE MEL. MAINTENANCE REPLACED THE RAT TR.