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

We propose to supersede Airworthiness Directive (AD) 2013-11- 03, which applies to certain Viking Air Limited Model CL-215-1A10 and CL-215-6B11 (CL-215T Variant) airplanes. AD 2013-11-03 requires repetitive detailed inspections for cracking of the left-hand (LH) and right-hand (RH) wing lower skin, and repair if necessary. AD 2013-11-03 was prompted by reports of a fractured wing lower rear spar cap and reinforcing strap. Since we issued AD 2013-11-03, further analysis has indicated the need for repetitive eddy current and borescope inspections. This proposed AD would require repetitive borescope inspections of the LH and RH wing lower skin and repetitive eddy current inspections of the LH and RH wing front and rear lower spar caps. We are proposing this AD to address the unsafe condition on these products.