As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE MECHANIC FOUND A CRACK WHILE PERFORMING AN AIRWORTHINESS INSP ON THE LT UPPER TAILBOOM TO HORIZ STABILIZER SUPPORT IN THE BEND RADIUS INTENDING TO OTBD EDGE FWD OF THE FIRST SCREW. NO HIDDEN DAMAGE WAS FOUND ON THE TAILBOOM UPON REMOVAL OF THE SUPPORT. THE CRACK MAY HAVE BEEN CAUSED BY PRELOADING IN THE BEND RADIUS DUE TO MISSING PFTE TAPE (C-460) ON FRAYED SURFACE OF THE LIQUID SHIM.