Airworthiness Directives; Bombardier Model DHC-8-102, -103, -106, -201, -202, -301, -311, and -315 Airplanes

Resumo

This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Bombardier Model DHC-8- 102, -103, -106, -201, -202, -301, -311, and -315 airplanes. This proposal would require inspection of the fitting assemblies located on the vent and scavenge lines routed immediately below the fuel tank access covers on both wings for proper installation, and corrective actions if necessary. This proposal also would require inspection of the stiffeners on the underside of fuel tank access covers on both wings for signs of chafing damage caused by incorrect orientation of the lockwire tail, and removal of damage. This action is necessary to prevent contact between the lockwire pigtail of the fitting and the stiffener located on the inside surface of the fuel access covers of the wings, which could serve as a potential ignition source within the fuel tank if a cover is struck by lightning and result in possible fuel tank explosion. This action is intended to address the identified unsafe condition.