Action
Supplemental notice of proposed rulemaking (NPRM); reopening of comment period.
Summary
The FAA is revising an earlier NPRM for an airworthiness directive (AD) that applies to all McDonnell Douglas Model DC-8 airplanes. The original NPRM would have superseded an existing AD that currently requires, among other things, revision of an existing program of structural inspections. The original NPRM proposed to require implementation of a revised program of structural inspections of baseline structure to detect and correct fatigue cracking in order to ensure the continued airworthiness of these airplanes as they approach the manufacturer's original fatigue design life goal. The original NPRM resulted from a significant number of these airplanes approaching or exceeding the design service goal on which the initial type certification approval was predicated. This new action revises the original NPRM by reducing the inspection threshold for certain principal structural elements. We are proposing this supplemental NPRM to detect and correct fatigue cracking that could compromise the structural integrity of these airplanes.