What was found
DURING 100-HOUR INSPECTION, FOUND 4 OF THE AN426 RIVETS SECURING THE UPPER HORIZONTAL STABILIZER SKIN PULLED COMPLETELY THROUGH ON THE LEFT SIDE. ALL OF THE REMAINING RIVETS BOTH LEFT AND RIGHT SIDE SHOWED SIGNS OF WORKING THESE RIVETS ARE INBOARD UNDER THE STABILZIER ROOT FAIRING. OLDER 172'S USE UNIVERSAL HEAD RIVETS WITH NO PROBLEMS OF WORKING. OBTAINED REPAIR PROCEDURE FROM CESSNA AND PROBLEM WAS CORRECTED.