AD 2021-24-18 86 FR 71815

The FAA is adopting a new airworthiness directive (AD) for all Viking Air Limited Model DHC-3 airplanes. This AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI identifies the unsafe condition as fatigue damage of the wing strut lug fitting components and the fuselage to wing strut attachment (tie-bar). This AD requires determining service life limits for the wing strut fitting on the main spar and for the tie-bar and following instructions for removal and replacement of affected parts. The FAA is issuing this AD to address the unsafe condition on these products.