Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Jetstream Model 4101 airplanes. This proposal would require repetitive detailed visual inspections to detect cracks on frame 179 at the attachment bracket for the door restraint cable, and various follow-on actions. This proposal also would require installation of new doublers and stress pads on frame 179, which would terminate the repetitive inspections. This proposal is prompted by reports of cracks in frame 179 of the fuselage at the attachment bracket for the door restraint cable on in-service airplanes due to improper rigging of the door restraint system. The actions specified by the proposed AD are intended to prevent such cracking, which could result in structural failure of the fuselage and consequent rapid decompression of the pressurized section of the fuselage.