Airworthiness Directives; Airbus SAS Airplanes

The FAA is adopting a new airworthiness directive (AD) for certain Airbus SAS Model A319-151N, -153N, -171N, and -173N airplanes; A320-251N, -252N, -253N, -271N, -272N, and -273N airplanes; A321-251N, -251NX, -252N, -252NX, -253N, -253NX, -253NY, -271N, -271NX, -272N, and -272NX airplanes. This AD was prompted by reports of lost synchronization between radio management panels (RMPs). This AD requires revising the existing airplane flight manual (AFM) by providing instructions to address dual loss of RMP data synchronization. The FAA is issuing this AD to address the unsafe condition on these products.