Airbus identified and contained a quality issue involving the surface protection applied to fuselage stringers on about 500 A321neos, including roughly 250 aircraft already in service and 250 in production. The company said the aircraft can continue operating because the defect poses no safety risk and that a remedy is available. Customers are continuing to accept deliveries without advance repairs, although European regulators may require fixes within a specified period. The issue comes as Airbus seeks to raise narrowbody production to 75 jets a month from about 60 and follows a separate fuselage-panel defect reported nine months earlier.