Airworthiness Directives; Bombardier, Inc., Airplanes

Official abstract: The FAA proposes to adopt a new airworthiness directive (AD) for certain Bombardier, Inc., Model CL-600-2B16 (604 Variants) airplanes. This proposed AD was prompted by reports of cracks being found on the lower wing plank at the rear spar wing station (WS) 59 to WS 65 web and/or flange. This proposed AD would require inspecting the lower wing plank rear spar web and lower flange, the forward surface of the pressure bulkhead frame under the stiffeners, and the vertical stabilizer front spar to frame attachment fitting lower legs for cracks, and repair or rectification if applicable. The FAA is proposing this AD to address the unsafe condition on these products.