AD FAA-2018-0758

We are adopting a new airworthiness directive (AD) for certain Airbus SAS Model A350-941 airplanes. This AD was prompted by a review of the Airbus A350 structure design principles database for type definition that revealed that the balancer fitting part, installed on the tail cone, on a certain frame (FR) has several corrosion-resistant stainless steel nuts that do not meet the requirements for protection against corrosion. This AD requires application of a new additional overcoat sealant and elastic varnish on the affected nuts and fasteners. We are issuing this AD to address the unsafe condition on these products.