Airworthiness Directives; Viking Air Limited (Type Certificate No. A-815 Formerly Held by Bombardier Inc. and de Havilland, Inc.) Model DHC-3 Airplanes

We are adopting a new airworthiness directive (AD) for the products listed above. This AD requires repetitively inspecting the elevator control tabs for discrepancies and, if any discrepancies are found, taking necessary corrective actions to bring all discrepancies within acceptable tolerances. This AD also requires reporting certain inspection results to the FAA. This AD was prompted by an evaluation of revisions to the manufacturer's maintenance manual that adds new repetitive inspections of the elevator control tabs. To require compliance with these inspections for U.S. owners and operators we are mandating the inspections through the rulemaking process. We are issuing this AD to add new repetitive inspections of the elevator control tabs. If these inspections are not done, excessive free-play in the elevator control tabs could develop. This condition could lead to loss of tab control linkage and severe elevator flutter. Such elevator flutter could lead to possible loss of control.