What was found
DURING 100 HOUR INSPECTION, THE HORIZONTAL STABILIZER WAS FOUND LOOSE. REMOVED DORSAL FIN, RUDDER AND ELEVATORS. FORWARD ATTACH BOLTS FOR HORIZONTAL STABILIZER WERE FOUND LOOSE. 9 RIVETS ON RIGHT HAND AFT VERTICAL SUPPORT ANGLE, (PN 442682 WERE FOUND SHEARED. CHECKED AND REPLACED SHEARED RIVETS. CONTACTED DER FOR REPAIR OF SPAR ATTACH HOLES AND HARDWARE. REPAIRED IAW SR. REPAIR CONSISTED OF GOING TO OVERSIZE HARDWARE FOR FRONT MOUNTING AND INSTALLING SHIM IN DOUBLER PLATE UNDER NUTPLATES. THE FLOATING NUTPLATE USED IN PRODUCTION ARE REPLACED WITH FIXED NUT PLATES. FLOATING NUTPLATES ALLOWED STABILIZER TO MOVE TOO MUCH WITH LOOOSE BOLTS AND ELONGATED HOLES IN STABILIZER.