Airworthiness Directives; Airbus SAS Airplanes

The FAA is adopting a new airworthiness directive (AD) for all Airbus SAS Model A319-151N, -153N, -171N, and -173N airplanes; Model A320-251N, -252N, -253N, -271N, -272N, and -273N airplanes; and Model A321-251N, -252N, -253N, -271N, -272N, -251NX, -252NX, -253NX, -271NX, -272NX, -253NY, and -271NY airplanes. This AD was prompted by occurrences of high-pressure bleed valve (HPV) butterfly seal retention clip rupture. This AD requires revising the existing airplane flight manual (AFM) and the existing FAA-approved minimum equipment list (MEL), allows replacement of each affected HPV as an optional terminating action, and prohibits the installation of affected parts. The FAA is issuing this AD to address the unsafe condition on these products.