[Federal Register Volume 88, Number 24 (Monday, February 6, 2023)]
[Rules and Regulations]
[Pages 7575-7578]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-02371]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2022-0874; Project Identifier AD-2022-00337-T;
Amendment 39-22307; AD 2023-01-13]
RIN 2120-AA64
Airworthiness Directives; The Boeing Company Airplanes
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
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SUMMARY: 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.
DATES: This AD is effective March 13, 2023.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of March 13,
2023.
ADDRESSES:
AD Docket: You may examine the AD docket at regulations.gov under
Docket No. FAA-2022-0874; or in person at Docket Operations between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD
docket contains this final rule, any comments received, and other
information. The address for Docket Operations is U.S. Department of
Transportation, Docket Operations, M-30, West Building Ground Floor,
Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590.
Material Incorporated by Reference:
For service information identified in this final rule,
contact Boeing
[[Page 7576]]
Commercial Airplanes, Attention: Contractual & Data Services (C&DS),
2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA 90740-5600;
telephone 562-797-1717; website myboeingfleet.com.
You may view this service information at the FAA,
Airworthiness Products Section, Operational Safety Branch, 2200 South
216th St., Des Moines, WA. For information on the availability of this
material at the FAA, call 206-231-3195. It is also available at
regulations.gov under Docket No. FAA-2022-0874.
FOR FURTHER INFORMATION CONTACT: Manuel Hernandez, Aerospace Engineer,
Airframe Section, FAA, Los Angeles ACO Branch, 3960 Paramount
Boulevard, Lakewood, CA 90712-4137; phone: 562-627-5256; email:
[email protected].
SUPPLEMENTARY INFORMATION:
Background
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 by adding an AD that would apply to 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. The NPRM
published in the Federal Register on August 31, 2022 (87 FR 53419). The
NPRM was prompted by an evaluation by the DAH indicating that certain
center wing lower stringers are subject to WFD. WFD analysis found that
fatigue cracks could grow to a critical length after the SMP for these
center wing lower stringers. In the NPRM, the FAA proposed to require
replacing certain left and right side center wing lower stringers. The
FAA is issuing this AD to address potential fatigue cracking of the
right and left side center wing lower stringers S-11 through S-22
between wing stations Xcw=13 and Xcw=15. If not addressed, undetected
fatigue cracks could grow to a critical length after the SMP at 81,740
total flight cycles. Any undetected cracks in three or more adjacent
stringers in the right or left side center wing lower stringers S-11
through S-22 may result in a principal structural element's inability
to sustain limit load, which could adversely affect the structural
integrity of the airplane. Performing the replacement required by this
AD terminates the repetitive inspections required by AD 2020-10-10
Amendment 39-19913 (85 FR 31046, May 22, 2020) (AD 2020-10-10, which
addresses the unsafe condition until the airplane reaches the SMP).
Discussion of Final Airworthiness Directive
Comments
The FAA received comments on the NPRM from Boeing, and three
individuals. The comments from one individual were outside the scope of
this rulemaking. The following presents the comments received and the
FAA's response to each comment.
Request To Allow Certified Non-Boeing Mechanics To Perform Replacements
An individual requested that a certified mechanic not hired by
Boeing be allowed to perform the replacement specified in the proposed
AD. The commenter stated that it appears that Boeing must take care of
the replacements, which must be paid for by the airplanes' owners,
which could create a conflict of interest. Another commenter suggested
that an external party should inspect the repaired airplanes to ensure
no further issues will arise.
The FAA agrees to clarify. Unless specified otherwise, ADs allow an
FAA-approved licensed mechanic authorized to do maintenance to perform
the replacement actions. Operators may therefore use a qualified
mechanic of their choice, and do not have to use a Boeing employee for
the replacements. The FAA has not changed this AD regarding this issue.
Request To Clarify Certain Language in the Background Section of the
Proposed AD
Boeing requested that certain language in the Background section of
the proposed AD be changed for clarification. Boeing asked that a
sentence describing AD 2020-10-10 be revised. The sentence in the NPRM
reads: ``AD 2020-10-10 requires repetitive inspections for cracking in
the left and right side center wing lower skin at stringers S-18
through S-20, the fastener holes common to stringers S-11 through S-22,
and the forward and aft skins, and repair.'' Boeing asked that the
sentence be revised to read: ``AD 2020-10-10 requires repetitive
inspections for cracking in the left and right side fastener holes
common to stringers S-11 through S-22 and the forward and aft skins,
and center wing lower skin at stringers S-18 through S-20, and
repair.'' Boeing stated that the revised language would correctly
identify the inspection requirements and list them in the same order as
the description in the service information.
The FAA agrees that the proposed wording better matches the
description in the service information. However, that sentence is not
carried over to this final rule. Therefore, the FAA has not changed
this AD regarding this issue.
Request To Clarify Certain Language in Paragraph (e) of the Proposed AD
Boeing requested that the language in paragraph (e) of the proposed
AD be clarified to specify that this AD is being issued to address
``potential'' fatigue cracking. Boeing stated that not all structure
subject to replacement will have developed fatigue cracking and that
the required action involves proactive replacement.
The FAA agrees with the request to change the language. The phrase
``address fatigue cracking'' in paragraph (e) of this AD has been
changed to read ``address potential fatigue cracking.''
Request To Clarify Certain Language in the Explanation of Compliance
Time Paragraph of the Proposed AD
Boeing requested that the language in the Explanation of Compliance
Time paragraph of the proposed AD be changed for clarification. Boeing
stated that all structure subject to replacement is certified type
design and not all will have developed fatigue cracking, therefore
replacing the term ``discrepant structure'' with the term ``certain
structure'' would be more consistent with the language of the SUMMARY
section.
The FAA agrees that not all structure subject to replacement will
have developed fatigue cracks at SMP. However, that sentence is not
carried over to this final rule. Therefore, the FAA has not changed
this AD regarding this issue.
Conclusion
The FAA reviewed the relevant data, considered any comments
received, and determined that air safety requires adopting this AD as
proposed. Accordingly, the FAA is issuing this AD to address the unsafe
condition on these products. Except for minor editorial changes, and
any other changes described previously, this AD is adopted as proposed
in the NPRM. None of the changes will increase the economic burden on
any operator.
Related Service Information Under 1 CFR Part 51
The FAA reviewed Boeing Alert Requirements Bulletin MD80-57A246 RB,
dated December 17, 2021. This service information specifies procedures
for replacement of the center wing lower stringers S-11 through S-22
between Xcw=0 and Xcw=121.688, left and right sides.
[[Page 7577]]
This service information is reasonably available because the
interested parties have access to it through their normal course of
business or by the means identified in ADDRESSES.
Costs of Compliance
The FAA estimates that this AD affects 22 airplanes of U.S.
registry. The FAA estimates the following costs to comply with this AD:
Estimated Costs
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Cost per Cost on U.S.
Action Labor cost Parts cost product operators
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Replacement........................... 1,572 work-hours x $85 $216,000 $349,620 $7,691,640
per hour = $133,620.
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Authority for This Rulemaking
Title 49 of the United States Code specifies the FAA's authority to
issue rules on aviation safety. Subtitle I, section 106, describes the
authority of the FAA Administrator. Subtitle VII: Aviation Programs,
describes in more detail the scope of the Agency's authority.
The FAA is issuing this rulemaking under the authority described in
Subtitle VII, Part A, Subpart III, Section 44701: General requirements.
Under that section, Congress charges the FAA with promoting safe flight
of civil aircraft in air commerce by prescribing regulations for
practices, methods, and procedures the Administrator finds necessary
for safety in air commerce. This regulation is within the scope of that
authority because it addresses an unsafe condition that is likely to
exist or develop on products identified in this rulemaking action.
Regulatory Findings
This AD will not have federalism implications under Executive Order
13132. This AD will not have a substantial direct effect on the States,
on the relationship between the national government and the States, or
on the distribution of power and responsibilities among the various
levels of government.
For the reasons discussed above, I certify that this AD:
(1) Is not a ``significant regulatory action'' under Executive
Order 12866,
(2) Will not affect intrastate aviation in Alaska, and
(3) Will not have a significant economic impact, positive or
negative, on a substantial number of small entities under the criteria
of the Regulatory Flexibility Act.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.
The Amendment
Accordingly, under the authority delegated to me by the
Administrator, the FAA amends 14 CFR part 39 as follows:
PART 39--AIRWORTHINESS DIRECTIVES
0
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
0
2. The FAA amends Sec. 39.13 by adding the following new airworthiness
directive:
2023-01-13 The Boeing Company: Amendment 39-22307; Docket No. FAA-
2022-0874; Project Identifier AD-2022-00337-T.
(a) Effective Date
This airworthiness directive (AD) is effective March 13, 2023.
(b) Affected ADs
This AD affects AD 2020-10-10, Amendment 39-19913 (85 FR 31046,
May 22, 2020) (AD 2020-10-10).
(c) Applicability
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.
(d) Subject
Air Transport Association (ATA) of America Code 57, Wings.
(e) Unsafe Condition
This AD was prompted by an evaluation by the design approval
holder (DAH) indicating that the center wing lower stringers S-11
through S-22 are subject to widespread fatigue damage (WFD). The FAA
is issuing this AD to address potential fatigue cracking of the
right and left side center wing lower stringers S-11 through S-22
between wing stations Xcw=13 and Xcw=15. If not addressed,
undetected fatigue cracks could grow to a critical length after the
structural modification point (SMP) at 81,740 total flight cycles.
Any undetected cracks in three or more adjacent stringers in the
right or left side center wing lower stringers S-11 through S-22 may
result in a principal structural element's inability to sustain
limit load, which could adversely affect the structural integrity of
the airplane.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Required Actions
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.
(h) Exceptions to Service Information Specifications
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.
(i) Terminating Action for AD 2020-10-10
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.
(j) Alternative Methods of Compliance (AMOCs)
(1) The Manager, Los Angeles ACO Branch, FAA, has the authority
to approve AMOCs for this AD, if requested using the procedures
found in 14 CFR 39.19. In accordance with 14 CFR 39.19, send your
request to your principal inspector or responsible Flight Standards
Office, as appropriate. If sending information directly to the
manager of the certification office, send it to the attention of the
person identified in paragraph (k) of this AD. Information may be
emailed to: [email protected].
(2) Before using any approved AMOC, notify your appropriate
principal inspector, or lacking a principal inspector, the manager
of the responsible Flight Standards Office.
[[Page 7578]]
(3) An AMOC that provides an acceptable level of safety may be
used for any repair, modification, or alteration required by this AD
if it is approved by The Boeing Company Organization Designation
Authorization (ODA) that has been authorized by the Manager, Los
Angeles ACO Branch, FAA, to make those findings. To be approved, the
repair method, modification deviation, or alteration deviation must
meet the certification basis of the airplane, and the approval must
specifically refer to this AD.
(k) Related Information
For more information about this AD, contact Manuel Hernandez,
Aerospace Engineer, Airframe Section, FAA, Los Angeles ACO Branch,
3960 Paramount Boulevard, Lakewood, CA 90712-4137; phone: 562-627-
5256; email: [email protected].
(l) Material Incorporated by Reference
(1) The Director of the Federal Register approved the
incorporation by reference (IBR) of the service information listed
in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
(2) You must use this service information as applicable to do
the actions required by this AD, unless the AD specifies otherwise.
(i) Boeing Alert Requirements Bulletin MD80-57A246 RB, dated
December 17, 2021.
(ii) [Reserved]
(3) For service information identified in this AD, contact
Boeing Commercial Airplanes, Attention: Contractual & Data Services
(C&DS), 2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA 90740-
5600; telephone 562-797-1717; website myboeingfleet.com.
(4) You may view this service information at the FAA,
Airworthiness Products Section, Operational Safety Branch, 2200
South 216th St., Des Moines, WA. For information on the availability
of this material at the FAA, call 206-231-3195.
(5) You may view this service information that is incorporated
by reference at the National Archives and Records Administration
(NARA). For information on the availability of this material at
NARA, [email protected], or go to: www.archives.gov/federal-register/cfr/ibr-locations.html.
Issued on January 13, 2023.
Gaetano A. Sciortino,
Acting Director, Compliance & Airworthiness Division, Aircraft
Certification Service.
[FR Doc. 2023-02371 Filed 2-3-23; 8:45 am]
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