Airworthiness Directives; The Boeing Company Airplanes, 53419-53421 [2022-18759]
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53419
Proposed Rules
Federal Register
Vol. 87, No. 168
Wednesday, August 31, 2022
This section of the FEDERAL REGISTER
contains notices to the public of the proposed
issuance of rules and regulations. The
purpose of these notices is to give interested
persons an opportunity to participate in the
rule making prior to the adoption of the final
rules.
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA–2022–0874; Project
Identifier AD–2022–00337–T]
RIN 2120–AA64
Airworthiness Directives; The Boeing
Company Airplanes
Federal Aviation
Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking
(NPRM).
AGENCY:
The FAA proposes to adopt 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 proposed 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
proposed AD would require replacing
certain left and right side center wing
lower stringers. The FAA is proposing
this AD to address the unsafe condition
on these products.
DATES: The FAA must receive comments
on this proposed AD by October 17,
2022.
ADDRESSES: You may send comments,
using the procedures found in 14 CFR
11.43 and 11.45, by any of the following
methods:
• Federal eRulemaking Portal: Go to
https://www.regulations.gov. Follow the
instructions for submitting comments.
• Fax: 202–493–2251.
• Mail: U.S. Department of
Transportation, Docket Operations, M–
30, West Building Ground Floor, Room
W12–140, 1200 New Jersey Avenue SE,
Washington, DC 20590.
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SUMMARY:
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• Hand Delivery: Deliver to Mail
address above between 9 a.m. and 5
p.m., Monday through Friday, except
Federal holidays.
For service information identified in
this NPRM, 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;
internet https://
www.myboeingfleet.com. You may view
this referenced 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 https://
www.regulations.gov by searching for
and locating Docket No. FAA–2022–
0874.
Examining the AD Docket
You may examine the AD docket at
https://www.regulations.gov by
searching for and locating 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
NPRM, any comments received, and
other information. The street address for
Docket Operations is listed above.
FOR FURTHER INFORMATION CONTACT:
Sean Newell, Aerospace Engineer,
Airframe Section, FAA, Los Angeles
ACO Branch, 3960 Paramount
Boulevard, Lakewood, CA 90712–4137;
phone: 562–627–5266; email:
sean.m.newell@faa.gov.
SUPPLEMENTARY INFORMATION:
Comments Invited
The FAA invites you to send any
written relevant data, views, or
arguments about this proposal. Send
your comments to an address listed
under ADDRESSES. Include ‘‘Docket No.
FAA–2022–0874; Project Identifier AD–
2022–00337–T’’ at the beginning of your
comments. The most helpful comments
reference a specific portion of the
proposal, explain the reason for any
recommended change, and include
supporting data. The FAA will consider
all comments received by the closing
date and may amend this proposal
because of those comments.
Except for Confidential Business
Information (CBI) as described in the
following paragraph, and other
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information as described in 14 CFR
11.35, the FAA will post all comments
received, without change, to https://
www.regulations.gov, including any
personal information you provide. The
agency will also post a report
summarizing each substantive verbal
contact received about this NPRM.
Confidential Business Information
CBI is commercial or financial
information that is both customarily and
actually treated as private by its owner.
Under the Freedom of Information Act
(FOIA) (5 U.S.C. 552), CBI is exempt
from public disclosure. If your
comments responsive to this NPRM
contain commercial or financial
information that is customarily treated
as private, that you actually treat as
private, and that is relevant or
responsive to this NPRM, it is important
that you clearly designate the submitted
comments as CBI. Please mark each
page of your submission containing CBI
as ‘‘PROPIN.’’ The FAA will treat such
marked submissions as confidential
under the FOIA, and they will not be
placed in the public docket of this
NPRM. Submissions containing CBI
should be sent to Sean Newell,
Aerospace Engineer, Airframe Section,
FAA, Los Angeles ACO Branch, 3960
Paramount Boulevard, Lakewood, CA
90712–4137; phone: 562–627–5266;
email: sean.m.newell@faa.gov. Any
commentary that the FAA receives that
is not specifically designated as CBI will
be placed in the public docket for this
rulemaking.
Background
Fatigue damage can occur locally, in
small areas or structural design details,
or globally, in widespread areas.
Multiple-site damage is widespread
damage that occurs in a large structural
element such as a single rivet line of a
lap splice joining two large skin panels.
Widespread damage can also occur in
multiple elements such as adjacent
frames or stringers. Multiple-site
damage and multiple-element damage
cracks are typically too small initially to
be reliably detected with normal
inspection methods. Without
intervention, these cracks will grow,
and eventually compromise the
structural integrity of the airplane. This
condition is known as WFD. It is
associated with general degradation of
large areas of structure with similar
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Federal Register / Vol. 87, No. 168 / Wednesday, August 31, 2022 / Proposed Rules
structural details and stress levels. As
an airplane ages, WFD will likely occur,
and will certainly occur if the airplane
is operated long enough without any
intervention.
An FAA final rule (‘‘Aging Airplane
Program: Widespread Fatigue Damage;’’
75 FR 69746, November 15, 2010)
became effective on January 14, 2011,
and amended 14 CFR parts 25, 26, 121,
and 129 (commonly known as the WFD
rule). The WFD rule requires certain
actions to prevent structural failure due
to WFD throughout the operational life
of certain existing transport category
airplanes and all of these airplanes that
will be certificated in the future. DAHs
of existing and future airplanes subject
to the WFD rule are required to establish
a limit of validity (LOV) of the
engineering data that support the
structural maintenance program.
Operators affected by the WFD rule may
not fly an airplane beyond its LOV,
unless an extended LOV is approved.
The WFD rule does not require
identifying and developing maintenance
actions if the DAHs can show that such
actions are not necessary to prevent
WFD before the airplane reaches the
LOV. Many LOVs, however, do depend
on accomplishment of future
maintenance actions. As stated in the
WFD rule, any maintenance actions
necessary to reach the LOV will be
mandated by airworthiness directives
through separate rulemaking actions.
In the context of WFD, this action is
necessary to enable DAHs to propose
LOVs that allow operators the longest
operational lives for their airplanes, and
still ensure that WFD will not occur.
This approach allows for an
implementation strategy that provides
flexibility to DAHs in determining the
timing of service information
development (with FAA approval),
while providing operators with certainty
regarding the LOV applicable to their
airplanes.
The FAA has received a report
indicating that cracking was found in
the left and/or right side center wing
lower stringers S–13, S–15, S–16, and
S–17. Based on that report, the FAA
issued AD 2020–10–10, Amendment
39–19913 (85 FR 31046, May 22, 2020)
(AD 2020–10–10). AD 2020–10–10 was
prompted by a report of cracks at certain
stringers and associated end fittings,
and skins in the center wing fuel tank
where the stringers meet the end
fittings. 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. Since the FAA issued
AD 2020–10–10, Boeing did additional
WFD analysis and found that the actions
required by AD 2020–10–10 are
adequate to address the unsafe
condition until the airplane reaches the
SMP (the point in time when a
structural area must be modified or
replaced to preclude WFD) at 81,740
flight cycles. However, fatigue cracks
could grow to a critical length at any
point after the SMP for center wing
lower stringers S–11 through S–22. If
not addressed, undetected fatigue cracks
in the right or left side center wing
lower stringers S–11 through S–22
between wing stations Xcw=13 and
Xcw=15 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 proposed
AD would terminate the repetitive
inspections required by AD 2020–10–
10.
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.
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.
Proposed AD Requirements in This
NPRM
This proposed AD would require
accomplishing the actions specified in
the service information already
described and except for any differences
identified as exceptions in the
regulatory text of this proposed AD. For
information on the procedures and
compliance times, see this service
information at https://
www.regulations.gov by searching for
and locating Docket No. FAA–2022–
0874.
Explanation of Compliance Time
The compliance time for the
replacement specified in this proposed
AD for addressing WFD was established
to ensure that discrepant structure is
replaced before WFD develops in
airplanes. Standard inspection
techniques cannot be relied on to detect
WFD before it becomes a hazard to
flight. The FAA will not grant any
extensions of the compliance time to
complete any AD-mandated service
bulletin related to WFD without
extensive new data that would
substantiate and clearly warrant such an
extension.
FAA’s Determination
Costs of Compliance
The FAA is issuing this NPRM after
determining that the unsafe condition
described previously is likely to exist or
develop on other products of the same
type design.
The FAA estimates that this AD, if
adopted as proposed, would affect 22
airplanes of U.S. registry. The FAA
estimates the following costs to comply
with this proposed AD:
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ESTIMATED COSTS
Action
Labor cost
Replacement ....................................
1,572 work-hours × $85 per hour = $133,620 ..............
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
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Parts cost
the FAA Administrator. Subtitle VII:
Aviation Programs, describes in more
detail the scope of the Agency’s
authority.
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$216,000
Cost per
product
$349,620
Cost on U.S.
operators
$7,691,640
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
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Federal Register / Vol. 87, No. 168 / Wednesday, August 31, 2022 / Proposed Rules
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
The FAA determined that this
proposed AD would not have federalism
implications under Executive Order
13132. This proposed AD would 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 this proposed regulation:
(1) Is not a ‘‘significant regulatory
action’’ under Executive Order 12866,
(2) Would not affect intrastate
aviation in Alaska, and
(3) Would 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 Proposed Amendment
Accordingly, under the authority
delegated to me by the Administrator,
the FAA proposes to amend 14 CFR part
39 as follows:
PART 39—AIRWORTHINESS
DIRECTIVES
1. The authority citation for part 39
continues to read as follows:
■
Authority: 49 U.S.C. 106(g), 40113, 44701.
§ 39.13
[Amended]
2. The FAA amends § 39.13 by adding
the following new airworthiness
directive:
■
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The Boeing Company: Docket No. FAA–
2022–0874; Project Identifier AD–2022–
00337–T.
(a) Comments Due Date
The FAA must receive comments on this
airworthiness directive (AD) by October 17,
2022.
(b) Affected ADs
This AD affects AD 2020–10–10,
Amendment 39–19913 (85 FR 31046, May 22,
2020) (AD 2020–10–10).
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16:49 Aug 30, 2022
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(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 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.
53421
(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)(1) of
this AD. Information may be emailed to: 9ANM-LAACO-AMOC-Requests@faa.gov.
(2) Before using any approved AMOC,
notify your appropriate principal inspector,
or lacking a principal inspector, the manager
of the responsible Flight Standards Office.
(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
(1) For more information about this AD,
contact Sean Newell, Aerospace Engineer,
Airframe Section, FAA, Los Angeles ACO
Branch, 3960 Paramount Boulevard,
Lakewood, CA 90712–4137; phone: 562–627–
5266; email: sean.m.newell@faa.gov.
(2) 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; internet https://
www.myboeingfleet.com. You may view this
referenced 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.
Issued on July 8, 2022.
Christina Underwood,
Acting Director, Compliance & Airworthiness
Division, Aircraft Certification Service.
[FR Doc. 2022–18759 Filed 8–30–22; 8:45 am]
BILLING CODE 4910–13–P
(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 (i) 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.
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA–2022–1065; Project
Identifier MCAI–2022–00280–T]
RIN 2120–AA64
Airworthiness Directives; Bombardier,
Inc., Airplanes
Federal Aviation
Administration (FAA), DOT.
AGENCY:
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]]>Agencies
[Federal Register Volume 87, Number 168 (Wednesday, August 31, 2022)]
[Proposed Rules]
[Pages 53419-53421]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-18759]
========================================================================
Proposed Rules
Federal Register
________________________________________________________________________
This section of the FEDERAL REGISTER contains notices to the public of
the proposed issuance of rules and regulations. The purpose of these
notices is to give interested persons an opportunity to participate in
the rule making prior to the adoption of the final rules.
========================================================================
Federal Register / Vol. 87, No. 168 / Wednesday, August 31, 2022 /
Proposed Rules
[[Page 53419]]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2022-0874; Project Identifier AD-2022-00337-T]
RIN 2120-AA64
Airworthiness Directives; The Boeing Company Airplanes
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).
-----------------------------------------------------------------------
SUMMARY: The FAA proposes to adopt 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 proposed 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 proposed AD would require replacing certain left and
right side center wing lower stringers. The FAA is proposing this AD to
address the unsafe condition on these products.
DATES: The FAA must receive comments on this proposed AD by October 17,
2022.
ADDRESSES: You may send comments, using the procedures found in 14 CFR
11.43 and 11.45, by any of the following methods:
Federal eRulemaking Portal: Go to https://www.regulations.gov. Follow the instructions for submitting comments.
Fax: 202-493-2251.
Mail: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue SE, Washington, DC 20590.
Hand Delivery: Deliver to Mail address above between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
For service information identified in this NPRM, 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; internet https://www.myboeingfleet.com. You may
view this referenced 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 https://www.regulations.gov by searching for and locating Docket No. FAA-2022-
0874.
Examining the AD Docket
You may examine the AD docket at https://www.regulations.gov by
searching for and locating 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 NPRM, any comments
received, and other information. The street address for Docket
Operations is listed above.
FOR FURTHER INFORMATION CONTACT: Sean Newell, Aerospace Engineer,
Airframe Section, FAA, Los Angeles ACO Branch, 3960 Paramount
Boulevard, Lakewood, CA 90712-4137; phone: 562-627-5266; email:
[email protected].
SUPPLEMENTARY INFORMATION:
Comments Invited
The FAA invites you to send any written relevant data, views, or
arguments about this proposal. Send your comments to an address listed
under ADDRESSES. Include ``Docket No. FAA-2022-0874; Project Identifier
AD-2022-00337-T'' at the beginning of your comments. The most helpful
comments reference a specific portion of the proposal, explain the
reason for any recommended change, and include supporting data. The FAA
will consider all comments received by the closing date and may amend
this proposal because of those comments.
Except for Confidential Business Information (CBI) as described in
the following paragraph, and other information as described in 14 CFR
11.35, the FAA will post all comments received, without change, to
https://www.regulations.gov, including any personal information you
provide. The agency will also post a report summarizing each
substantive verbal contact received about this NPRM.
Confidential Business Information
CBI is commercial or financial information that is both customarily
and actually treated as private by its owner. Under the Freedom of
Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public
disclosure. If your comments responsive to this NPRM contain commercial
or financial information that is customarily treated as private, that
you actually treat as private, and that is relevant or responsive to
this NPRM, it is important that you clearly designate the submitted
comments as CBI. Please mark each page of your submission containing
CBI as ``PROPIN.'' The FAA will treat such marked submissions as
confidential under the FOIA, and they will not be placed in the public
docket of this NPRM. Submissions containing CBI should be sent to Sean
Newell, Aerospace Engineer, Airframe Section, FAA, Los Angeles ACO
Branch, 3960 Paramount Boulevard, Lakewood, CA 90712-4137; phone: 562-
627-5266; email: [email protected]. Any commentary that the FAA
receives that is not specifically designated as CBI will be placed in
the public docket for this rulemaking.
Background
Fatigue damage can occur locally, in small areas or structural
design details, or globally, in widespread areas. Multiple-site damage
is widespread damage that occurs in a large structural element such as
a single rivet line of a lap splice joining two large skin panels.
Widespread damage can also occur in multiple elements such as adjacent
frames or stringers. Multiple-site damage and multiple-element damage
cracks are typically too small initially to be reliably detected with
normal inspection methods. Without intervention, these cracks will
grow, and eventually compromise the structural integrity of the
airplane. This condition is known as WFD. It is associated with general
degradation of large areas of structure with similar
[[Page 53420]]
structural details and stress levels. As an airplane ages, WFD will
likely occur, and will certainly occur if the airplane is operated long
enough without any intervention.
An FAA final rule (``Aging Airplane Program: Widespread Fatigue
Damage;'' 75 FR 69746, November 15, 2010) became effective on January
14, 2011, and amended 14 CFR parts 25, 26, 121, and 129 (commonly known
as the WFD rule). The WFD rule requires certain actions to prevent
structural failure due to WFD throughout the operational life of
certain existing transport category airplanes and all of these
airplanes that will be certificated in the future. DAHs of existing and
future airplanes subject to the WFD rule are required to establish a
limit of validity (LOV) of the engineering data that support the
structural maintenance program. Operators affected by the WFD rule may
not fly an airplane beyond its LOV, unless an extended LOV is approved.
The WFD rule does not require identifying and developing
maintenance actions if the DAHs can show that such actions are not
necessary to prevent WFD before the airplane reaches the LOV. Many
LOVs, however, do depend on accomplishment of future maintenance
actions. As stated in the WFD rule, any maintenance actions necessary
to reach the LOV will be mandated by airworthiness directives through
separate rulemaking actions.
In the context of WFD, this action is necessary to enable DAHs to
propose LOVs that allow operators the longest operational lives for
their airplanes, and still ensure that WFD will not occur. This
approach allows for an implementation strategy that provides
flexibility to DAHs in determining the timing of service information
development (with FAA approval), while providing operators with
certainty regarding the LOV applicable to their airplanes.
The FAA has received a report indicating that cracking was found in
the left and/or right side center wing lower stringers S-13, S-15, S-
16, and S-17. Based on that report, the FAA issued AD 2020-10-10,
Amendment 39-19913 (85 FR 31046, May 22, 2020) (AD 2020-10-10). AD
2020-10-10 was prompted by a report of cracks at certain stringers and
associated end fittings, and skins in the center wing fuel tank where
the stringers meet the end fittings. 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.
Since the FAA issued AD 2020-10-10, Boeing did additional WFD analysis
and found that the actions required by AD 2020-10-10 are adequate to
address the unsafe condition until the airplane reaches the SMP (the
point in time when a structural area must be modified or replaced to
preclude WFD) at 81,740 flight cycles. However, fatigue cracks could
grow to a critical length at any point after the SMP for center wing
lower stringers S-11 through S-22. If not addressed, undetected fatigue
cracks in the right or left side center wing lower stringers S-11
through S-22 between wing stations Xcw=13 and Xcw=15 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 proposed AD would terminate
the repetitive inspections required by AD 2020-10-10.
FAA's Determination
The FAA is issuing this NPRM after determining that the unsafe
condition described previously is likely to exist or develop on other
products of the same type design.
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.
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.
Proposed AD Requirements in This NPRM
This proposed AD would require accomplishing the actions specified
in the service information already described and except for any
differences identified as exceptions in the regulatory text of this
proposed AD. For information on the procedures and compliance times,
see this service information at https://www.regulations.gov by
searching for and locating Docket No. FAA-2022-0874.
Explanation of Compliance Time
The compliance time for the replacement specified in this proposed
AD for addressing WFD was established to ensure that discrepant
structure is replaced before WFD develops in airplanes. Standard
inspection techniques cannot be relied on to detect WFD before it
becomes a hazard to flight. The FAA will not grant any extensions of
the compliance time to complete any AD-mandated service bulletin
related to WFD without extensive new data that would substantiate and
clearly warrant such an extension.
Costs of Compliance
The FAA estimates that this AD, if adopted as proposed, would
affect 22 airplanes of U.S. registry. The FAA estimates the following
costs to comply with this proposed AD:
Estimated Costs
----------------------------------------------------------------------------------------------------------------
Cost per Cost on U.S.
Action Labor cost Parts cost product operators
----------------------------------------------------------------------------------------------------------------
Replacement........................... 1,572 work-hours x $85 $216,000 $349,620 $7,691,640
per hour = $133,620.
----------------------------------------------------------------------------------------------------------------
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
[[Page 53421]]
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
The FAA determined that this proposed AD would not have federalism
implications under Executive Order 13132. This proposed AD would 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 this proposed
regulation:
(1) Is not a ``significant regulatory action'' under Executive
Order 12866,
(2) Would not affect intrastate aviation in Alaska, and
(3) Would 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 Proposed Amendment
Accordingly, under the authority delegated to me by the
Administrator, the FAA proposes to amend 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:
The Boeing Company: Docket No. FAA-2022-0874; Project Identifier AD-
2022-00337-T.
(a) Comments Due Date
The FAA must receive comments on this airworthiness directive
(AD) by October 17, 2022.
(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 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
(i) 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)(1) 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.
(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
(1) For more information about this AD, contact Sean Newell,
Aerospace Engineer, Airframe Section, FAA, Los Angeles ACO Branch,
3960 Paramount Boulevard, Lakewood, CA 90712-4137; phone: 562-627-
5266; email: [email protected].
(2) 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; internet https://www.myboeingfleet.com. You may view this referenced 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.
Issued on July 8, 2022.
Christina Underwood,
Acting Director, Compliance & Airworthiness Division, Aircraft
Certification Service.
[FR Doc. 2022-18759 Filed 8-30-22; 8:45 am]
BILLING CODE 4910-13-P
