Airworthiness Directives; Leonardo S.p.a. Helicopters

The FAA is adopting a new airworthiness directive (AD) for all Leonardo S.p.a. Model AW189 helicopters. This AD was prompted by a report of abnormal oscillatory behavior during automated glide slope approaches, due to sealant on the glide slope (G/S) antenna coaxial connectors. This AD requires visually inspecting certain G/S antennas and G/S antenna coaxial connectors for the presence of any sealant; cleaning parts and removing any sealant; performing an external G/S acceptance test procedure (ATP); and taking corrective actions if necessary. This AD would also prohibit installing certain G/S antennas and G/S antenna coaxial connecters. These requirements are specified in a European Union Aviation Safety Agency (EASA) AD, which is incorporated by reference. The FAA is issuing this AD to address the unsafe condition on these products.