Airworthiness Directives; Bombardier, Inc., Airplanes

The FAA is superseding Airworthiness Directive (AD) 2021-20- 13, which applied to certain Bombardier, Inc., Model CL-600-2B16 (604 Variant) airplanes. AD 2021-20-13 required repetitive lubrication and repetitive detailed visual inspections (DVI) and non-destructive test (NDT) inspections of the main landing gear (MLG) shock strut lower pins, and replacement if necessary. This AD continues to require the lubrication and inspections specified in AD 2021-20-13 until the MLG shock strut assembly is modified by replacing the trailing arm bushing and installing new dynamic joint components. This AD was prompted by a new design solution for this potential failure of the shock strut lower pin. The FAA is issuing this AD to address the unsafe condition on these products.