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.

The new AD2024-03-06  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.

Action Needed

Within 60 months from the effective date of this AD, modify the LH and RH MLG assembly in accordance with paragraph 2.B. of the Accomplishment Instructions of the applicable service bulletin, as specified in paragraphs (k)(1) through (3) of this AD.

(1) For airplanes having S/N 5301 through 5665 inclusive: Bombardier Service Bulletin

604–32–031, Revision 01, dated March 17, 2023.

(2) For airplanes having S/N 5701 through 5988 inclusive: Bombardier Service Bulletin 605–32–008, Revision 01, dated March 17, 2023.

(3) For airplanes having S/N 6050 through 6188 inclusive: Bombardier Service Bulletin

650–32–005, Revision 01, dated March 17, 2023.

Modifying and testing an airplane as required by paragraphs (k) and (l) of this AD terminates the initial and repetitive lubrication and inspections required by paragraphs (g), (h), and (i) of this AD for that airplane.

This paragraph provides credit for actions required by paragraphs (k) and (l) of this AD, if those actions were performed before the effective date of this AD using Bombardier Service Bulletin 604–32–031, dated December 29, 2022; Bombardier Service Bulletin 605–32–008, dated December 29, 2022; or Bombardier Service Bulletin 650–32–005, dated December 29, 2022.