AD FAA-2018-0164

We are adopting a new airworthiness directive (AD) for certain Airbus Model A320-214, -251N, and -271N airplanes. This AD requires an inspection for any damaged bolt and nut in each cargo fire extinguishing bottle installation, and replacement of any damaged bolt and nut. This AD was prompted by a report that a dynamometric key, previously used for installing the cargo fire extinguishing bottle system, was out of tolerance. As a result, an incorrect torque value may have been applied to the bolts maintaining the fire extinguishing bottles in place. We are issuing this AD to address the unsafe condition on these products.