What was found
SIGNIFICANT TAIL PIPE FIRE DAMAGE FOUND ON POSTFLIGHT WALKAROUND, ON INBOARD AILERON, AND BOTH CANOE FAIRINGS ADJACENT TO THE AILERON ON THE NR 2 ENGINE SIDE (INWORK) WORKING IN CONJUNCTION WITH WRI 73-10/4991, CHECKED COMBUSTER DRAIN VALVE IAW M/M. NO DEFECTS NOTED. REMOVED AND REPLACED COMBUSTOR DRAIN VALVE PRECAUTIONARY IAW M/M. NO FUEL NOTED IN DRAIN LINE. IAW MOCC, NR 2 ENG MEC REQUIRES CHANGING PRIOR TO NEXT ENGINE START.