Airworthiness Directives; Viking Air Limited (Type Certificate Previously Held by Bombardier, Inc. and de Havilland, Inc.) Airplanes

The FAA is superseding Airworthiness Directive (AD) 89-24-06 R1, which applied to all Boeing of Canada, Ltd. and de Havilland (now Viking Air Limited) Model DHC-6-1, DHC-6-100, DHC-6-200, and DHC-6-300 airplanes. AD 89-24-06 R1 required repetitively inspecting the elevator quadrant for damage and taking corrective action as necessary. Since the FAA issued AD 89-24-06 R1, Transport Canada, the aviation authority for Canada, revised its mandatory continuing airworthiness information (MCAI) to correct this unsafe condition on these products. This AD retains the actions required by AD 89-24-06 R1, extends the compliance time intervals for the repetitive inspections, adds Model DHC-6-400 airplanes to the applicability, and adds a fluorescent penetrant inspection requirement. The FAA is issuing this AD to address the unsafe condition on these products.