During an unscheduled maintenance, Singapore Airlines and Qantas Airlines reported that they have discovered cracks in some of the wing ribs of their A380 aircraft. Following that Airbus has informed the airlines operating its A380 airliners to check for small cracks in wing rib skins attachment and informed that the cracks are not critical and not a safety problem. Moreover, Airbus claims that these cracks were created due to unexpected stresses being imparted to the component during the manufacturing process. The European plan maker has confirmed that the cracks are found in various parts of the wing rib attachments. Based on the location at which these cracks occur, they were either classified to be Type I or Type II (According to Airbus All Operator Telex terminology). Type I cracks extend from the bolt holes to the edge of the wing rib of the L shaped flange of the wing rib brackets while Type II cracks occur at the center of wing-rib feet.
These cracks were caused by high stress and type of aluminium alloy used for manufacturing the wing. Airbus claims that the aluminium alloy-7449, which has been used to manufacture the wing ribs tends to be sensitive to the way the parts are assembled and the defects have been introduced during the manufacturing process. The attached report will access various NDT techniques so as to recommend the manufacturer with the most suitable technique to detect the presence of Type I and Type II defects during the manufacturing stage.