Airworthiness Directive · Amendment 39-22307 · Wings
The Boeing Company Airplanes
This AD applies to The Boeing Company Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), and DC-9-87 (MD-87) airplanes; and Model MD-88 airplanes, certificated in any category, as identified in Boeing Alert Requirements Bulletin MD80-57A246 RB, dated December 17, 2021.
The FAA is adopting a new airworthiness directive (AD) for certain The Boeing Company Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC- 9-83 (MD-83), and DC-9-87 (MD-87) airplanes; and Model MD-88 airplanes. This AD was prompted by an evaluation by the design approval holder (DAH) indicating that certain center wing lower stringers are subject to widespread fatigue damage (WFD). WFD analysis found that fatigue cracks could grow to a critical length after the structural modification point (SMP) for these center wing lower stringers. This AD requires replacing certain left and right side center wing lower stringers. The FAA is issuing this AD to address the unsafe condition on these products.
Except as specified by paragraph (h) of this AD: At the applicable times specified in the “Compliance” paragraph of Boeing Alert Requirements Bulletin MD80-57A246 RB, dated December 17, 2021, do all applicable actions identified in, and in accordance with, the Accomplishment Instructions of Boeing Alert Requirements Bulletin MD80-57A246 RB, dated December 17, 2021.
Note 1 to paragraph (g): Guidance for accomplishing the actions required by this AD can be found in Boeing Alert Service Bulletin MD80-57A246, dated December 17, 2021, which is referred to in Boeing Alert Requirements Bulletin MD80-57A246 RB, dated December 17, 2021.
Where Boeing Alert Requirements Bulletin MD80-57A246 RB, dated December 17, 2021, specifies contacting Boeing for replacement instructions: This AD requires doing the replacement using a method approved in accordance with the procedures specified in paragraph (j) of this AD.
Accomplishment of the replacement specified in the Accomplishment Instructions of Boeing Alert Requirements Bulletin MD80-57A246 RB, dated December 17, 2021, terminates all of the requirements of AD 2020-10-10.
