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

Samenvatting

We propose to supersede an existing airworthiness directive (AD) that applies to the products listed above. The existing AD currently 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. The existing AD also requires reporting certain inspection results to the FAA. Since we issued that AD, we determined that we inadvertently omitted certain airplanes from the Applicability section. This proposed AD would retain the actions currently required in AD 2011-05-02 and remove the Supplemental Type Certificate (STC) SA01059SE condition in the Applicability section. We are proposing 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.