Summary
This document proposes to supersede an existing airworthiness directive (AD), applicable to all Airbus Model A300 B2, A300 B4, A310, A330, and A340 series airplanes; all Model A300 B4-600, A300 B4-600R, and A300 F4-600R (collectively called A300-600) series airplanes; and all A319, A320, A321 series airplanes. That AD requires repetitive checks of the alternate braking system, and replacement of the braking dual distribution valve (BDDV) if necessary. This action would require, for certain airplanes, inspecting and/or replacing the BDDV cover with an improved cover. For all other airplanes, this action would provide for optional termination of the repetitive checks. This action would also revise the applicability of the existing AD. This proposal is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by the proposed AD are intended to prevent failure of the alternate braking system, which could result in the airplane overrunning the end of the runway during landing.