Summary
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 series airplanes. This proposal would require repetitive inspections for discrepancies of certain rear spar fittings between the flex shaft of the flap secondary drive and the wing-to-fuselage structure, and corrective action if necessary. This proposal also provides for an optional modification of the flex shaft installation, which would terminate the repetitive inspections. This action is necessary to find and fix damage and subsequent failure of the rear spar fittings, which could result in loss of the wing. This action is intended to address the identified unsafe condition.