What was found
SHORTLY AFTER TAKEOFF, SMOKE WAS REPORTED, SURGE OF NR 2 ENGINE FOLLOWED. INSPECTION AFTER STRIPPING, FOUND THAT 1 HPT STAGE, 2 VANE HAD BEEN LIBERATED. ALL HP AND LP TURBINE AIRFOILS WERE SUBSEQUENTLY DAMAGED. INVESTIGATION SUGGEST HPT STAGE 2 VANE FORWRD OUTER FLANGE FAILED ALLOWING VIBRATION AND FRETTING. SUPPORT TO THIS SIS EVIDANCE OF SULPHIDATION OF FORWARD OUTER FLANGE SURFACE.