What was found
BORESCOPE EVALUATION OF THE ENGINE PRIOR TO REMOVAL OF THE CT VANE RING SHOWED RUB ON THE L/E OF THE CT BLADES. ON THE CT VANE RING, ONE OF AIRFOILS SHOWED A "THUMBNAIL" TYPE INSERT ON THE T/E OF ONE AIRFOIL WHICH WAS PARTIALLY LIBERATED AND FOLDED BACK INTO THE GAS PATH. THE INSERT IN FOLDING BACK IMPINGED ON THE L/E OF THE CT BLADES AND RESULTED IN HEAVY RUB. VISUAL EXAMINATION OF THE REST OF THE VANE RING SHOWED THE REMAINING 13 AIRFOILS ALL HAVE HAD A THUMBNAIL TYPE INSERT SIMILAR TO THE FAILED AIRFOIL. THE INSERT EXTENDS BACK FROM THE TRAILING EDGE APPROXIMATELY 1.25" WITH A WIDTH OF .700". THE INSERT EXISTS IN BOTH THE CONVEX AND CONCAVE AIRFOILS WITH A DISTINCT LINE BETWEEN THE INSERT AND THE VANE RING. IT APPEARS THAT SINCE A DISTINCT LINE EXISTS THAT THE INSERT WAS NOT WELDED IN PLACE BUT RATHER BRAZED. THE INSERT APPEARS TO HAVE BEEN MFG FROM 2 PIECES OF FLAT STOCK WELDED ON ONE EDGE TO FORM THE T/E OF THE VANE.