What was found
AIRCRAFT GROUNDED FOR HEAVY MAINTENANCE. APU FIRE WALL FORWARD SIDE HAS SEVERAL CRACKS AT VERTICAL STIFFENERS, ACCESS 313AL. APU FIREWALL FORWARD SIDE WEB CRACKS REPAIRED IAW SRM 53-80-30, FIG 201, REPAIR 1, DWG 353T0400, IAW 47233REA01.