Summary
The FAA proposes to supersede Airworthiness Directive (AD) AD 89-24-06 R1, which applies 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. This AD requires repetitively inspecting the elevator quadrant for damage and taking corrective action as necessary. Since the FAA issued AD 89-24-06 R1, the aviation authority for Canada revised its mandatory continuing airworthiness information (MCAI) to correct this unsafe condition on these products. The MCAI identifies the unsafe condition as damage to the flight control system. This proposed AD would retain the actions of AD 89-24-06 R1, extend the compliance time intervals for the repetitive inspections, add the Model DHC-6-400 airplane to the applicability, and add a fluorescent penetrant inspection requirement. The FAA is proposing this AD to address the unsafe condition on these products.