AN AIRBUS 320 DURING MAINT CHECK WAS FOUND TO HAVE 3 CRACKS APPROX .001 INCH IN LENGTH FROM HI-LOK FASTENER HOLES IN THE VERTICAL STABILIZER FORWARD SPAR.

Narrative

AFTER REMOVING VERT STAB PANEL 321AL TO INSPECT WIRING HARNESSES PER OUR JOB CARD; WE NOTICED SMALL CRACKS PROPAGATING FROM 2 HI-LOK FASTENERS ON THE FRONT SPAR NEXT TO THE TRANSVERSE LOAD FITTINGS. WE INFORMED INSPECTION AND THEY MADE A WRITE-UP. AT THIS TIME ENGINEERING IS STILL TRYING TO DECIDE WHAT TO DO. THERE IS NO TYPE OF NDT THAT WILL TELL US HOW DEEP THE CRACKS ARE. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE JOB CARD BEING WORKED WAS TO CHECK THE ELECTRICAL BRAIDED CONDUIT THAT WAS ATTACHED TO THE VERT STAB FORWARD SPAR. THE RPTR SAID TWO HI-LOK FASTENERS ON A DIAGONAL BRACE APPEARED TO HAVE CRACKS RADIATING FROM THE HOLES DRILLED IN THE WEB OF THE SPAR. THE RPTR STATED ONE HOLE HAD TWO CRACKS AND THE OTHER HOLE HAD ONLY ONE. THE RPTR SAID THE CRACKS WERE APPROX .001 INCH IN LENGTH AND WERE WRITTEN UP FOR INSPECTOR AND ENGINEERING FILLIP. THE RPTR STATED THE INSPECTORS WERE ABLE TO FINESSE A BORESCOPE IN THE TWO HOLES AND BELIEVE THE CRACKS WENT THROUGH THE .50 INCH WEB. THE RPTR SAID THE SPAR IS OF COMPOSITE CONSTRUCTION AND NO NON-DESTRUCTIVE TESTING METHODS OR INSTRUMENTS ARE PRESENTLY AVAILABLE AND NO REPAIR PROCS ARE IN THE STRUCTURAL REPAIR MANUAL. CALLBACK CONVERSATION WITH RPTR ACN 611593 REVEALED THE FOLLOWING INFO: THE RPTR STATED THE CRACKS WERE FOUND ON A JOB CARD THAT INSPECTED THE BRAIDED CONDUIT ON THE FORWARD VERT STABILIZER SPAR. THE RPTR SAID THE HI-LOK FASTENERS WERE ATTACHED TO A DIAGONAL SUPPORT NEAR THE TRANSVERSE LOAD FITTINGS. THE RPTR STATED THE HI-LOK FASTENERS WERE REMOVED AND ONE HOLE HAD TWO CRACKS AND THE OTHER ONE CRACK. THE RPTR SAID ALL THE CRACKS WERE ESTIMATED TO BE ABOUT .001 INCH IN LENGTH AND APPEARED TO BE THROUGH THE WEB; WHICH IS .50 INCH THICK. THE RPTR STATED THE STRUCTURAL REPAIR MANUAL DOES NOT ADDRESS THIS SITUATION FOR TESTING OR REPAIR.