What was found
WHILE CONDUCTING A POST FLIGHT INSP, THE FLIGHT CREW NOTICED THAT THE TAILBOOM HAD AN AREA THAT WAS DELAMINATED ON THE RT SIDE OF THE TAILBOOM. THIS IS IN THE SAME CRITICAL AREA THAT HAS BEEN ADDRESSED BY AD 2009-19-51. IN ADDITION TO THE DELAMINATED AREA, THERE WAS A OUTWARD PROTRUDING VERTICAL CREASE IN THE MIDDLE OF THE DELAMINATED AREA. THE FLIGHT CREW DID NOT REPORT ANYTHING UNUSUAL DURING THE FLIGHT. THE DAMAGE FROM TOP TO BOTTOM IT IS 25" INCH AND 12" INCH SIDE TO SIDE. THE SKIN IS ALSO CRACKED ALONG WHAT APPEARS TO BE A BOND LINE. MFG HAS ISSUED OPTIONAL TECH BULLETINS BT 139-159 FOR "TAILBOOM RETRO-MODIFICATION PROCEDURE" AND BT 139-200 FOR "TAILBOOM REINFORCEMENT STRUCTURAL RETRO-MODIFICATION" TO PREVENT STRUCTURAL FAILURE OF THIS NATURE. THESE BULLETINS HAVE NOT YET BEEN INCORPORATED ON THE SUBJECT ACFT.