Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain British Aerospace BAe Model ATP airplanes. This proposal would require repetitive inspections to detect uneven wear of the heat pack of the main landing gear (MLG) brake unit; measurement and setting of the wear remaining length (WRL) of the wear indicator pin (WIP); and replacement of the brake heat pack unit with a serviceable unit, if necessary. 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 detect uneven wear of the brake heat pack unit and prevent failure of the pressure stator of the MLG brake unit, which could result in reduced braking efficiency and consequent longer stopping distances upon landing.