Regulacje i polityka gospodarcza · 23/10/1996

Airworthiness Directives; McDonnell Douglas Model DC-9 Series Airplanes

This document proposes the supersedure of an existing airworthiness directive (AD), applicable to certain McDonnell Douglas DC-9 series airplanes, that currently requires repetitive visual inspections to detect corrosion and cracking of the fuselage upper skin and frames in the area of the loop antenna assemblies of the automatic direction finder (ADF), and repair, if necessary. This action would add a requirement to perform a visual and an eddy current inspection of the fuselage forward upper skin under the antennas, followed by the reinstallation of the ADF antennas using an improved procedure. This proposal is prompted by the development of a modification of the ADF antenna installation that would constitute terminating action for the required repetitive visual inspections. The actions specified by the proposed AD are intended to prevent rapid decompression of the fuselage, significant structural damage, and subsequent reduced structural integrity of the airplane, due to problems associated with corrosion and fatigue cracking in the subject area.