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

This amendment adopts a new airworthiness directive (AD), applicable to certain Bombardier Model DHC-8-102, -103, -106, -201, - 202, -301, -311, and -315 series airplanes, that requires 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 action also provides for an optional modification of the flex shaft installation, which terminates the repetitive inspections. This action is necessary to find and fix damage and prevent 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.