Summary
The FAA is revising an earlier NPRM for an airworthiness directive (AD) that applies to all Model BAe 146 airplanes and Model Avro 146-RJ airplanes. The original NPRM would have superseded an existing AD that currently requires revising the Airworthiness Limitations Section (ALS) of the Instructions for Continued Airworthiness to incorporate life limits for certain items and inspections to detect fatigue cracking in certain structures. The original NPRM proposed to require incorporating new and more restrictive life limits for certain items and for certain inspections to detect fatigue cracking in certain structures. The original NPRM resulted from issuance of a later revision to the airworthiness limitations. This new action revises the original NPRM by proposing to require revisions to the airworthiness limitations to include Critical Design Configuration Control Limitations for the fuel system. We are proposing this supplemental NPRM to ensure that fatigue cracking of certain structural elements is detected and corrected, and to prevent ignition sources in the fuel tanks; fatigue cracking of certain structural elements could adversely affect the structural integrity of these airplanes.