AD 2021-09-06

[Federal Register Volume 86, Number 84 (Tuesday, May 4, 2021)]
[Rules and Regulations]
[Pages 23595-23599]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2021-08849]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2020-0789; Project Identifier AD-2020-00849-T; 
Amendment 39-21519; AD 2021-09-06]
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 superseding Airworthiness Directive (AD) 2019-22-
10, which applied to all The Boeing Company Model 737-600, -700, -700C, 
-800, -900, and -900ER series airplanes. AD 2019-22-10 required 
repetitive inspections for cracking of the left- and right-hand side 
outboard chords of frame fittings and failsafe straps at a certain 
station around eight fasteners, and repair if any cracking is found. 
For certain airplanes, this AD reduces the compliance time for the 
initial inspection, and for all airplanes this AD reduces the 
repetitive interval. This AD was prompted by a determination that the 
initial inspection threshold and repetitive inspection interval are 
inadequate to address the cracking in a timely manner. The FAA is 
issuing this AD to address the unsafe condition on these products.

DATES: This AD is effective June 8, 2021.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of June 8, 
2021.
    The Director of the Federal Register approved the incorporation by 
reference of a certain other publication listed in this AD as of 
November 13, 2019 (84 FR 61533, November 13, 2019).
    The Director of the Federal Register approved the incorporation by 
reference of a certain other publication listed in this AD as of 
October 3, 2019 (84 FR 52754, October 3, 2019).

ADDRESSES: For service information identified in this final rule, 
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 <a href="https://www.myboeingfleet.com">https://www.myboeingfleet.com</a>. 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 on 
the internet at <a href="https://www.regulations.gov">https://www.regulations.gov</a> by searching for and 
locating Docket No. FAA-2020-0789.

Examining the AD Docket

    You may examine the AD docket on the internet at <a href="https://www.regulations.gov">https://www.regulations.gov</a>by searching for and locating Docket No. FAA-2020-
0789; 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.

[[Page 23596]]


FOR FURTHER INFORMATION CONTACT: Greg Rutar, Aerospace Engineer, 
Airframe Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des 
Moines, WA 98198; phone and fax: 206-231-3529; email: 
<a href="/cdn-cgi/l/email-protection#2c6b5e494b027e59584d5e6c4a4d4d024b435a"><span class="__cf_email__" data-cfemail="5c1b2e393b720e29283d2e1c3a3d3d723b332a">[email&#160;protected]</span></a>.

SUPPLEMENTARY INFORMATION:

Background

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 to supersede AD 2019-22-10, Amendment 39-19789 (84 FR 
61533, November 13, 2019) (AD 2019-22-10). AD 2019-22-10 applied to all 
The Boeing Company Model 737-600, -700, -700C, -800, -900, and -900ER 
series airplanes. The NPRM published in the Federal Register on 
September 8, 2020 (85 FR 55391). The NPRM was prompted by an 
engineering analysis of the inspection reporting results and 
metallurgical evaluation of the submitted frame fitting assemblies, 
which indicated that the initial inspection threshold for Model 737-
900ER series airplanes and the repetitive inspection interval for all 
affected airplanes are inadequate to address the cracking in a timely 
manner. For certain airplanes, the NPRM proposed to reduce the 
compliance time for the initial inspection, and for all airplanes the 
NPRM proposed to reduce the repetitive inspection interval.

Comments

    The FAA gave the public the opportunity to participate in 
developing this AD. The following presents the comments received on the 
NPRM and the FAA's response to each comment.

Request To Extend the Compliance Time for the Reporting Requirement

    American Airlines (AA) asked that the compliance time for the 
reporting requirements in paragraphs (h) and (k) of the proposed AD be 
extended to 30 days after the date of inspection. AA stated that the 
cracking of the station (STA) 663.75 fitting is now a known problem, 
and Boeing has been receiving reports for almost a year. AA added that 
extending the reporting requirement to 30 days would provide relief to 
the operators while not decreasing safety. Hainan Airlines (HNA) 
recommended that the compliance time for the reporting requirement in 
paragraph (k) of the proposed AD be extended from 3 to 30 days after 
the inspection or after the effective date of the proposed AD, or an 
equivalent date, to alleviate the burden on operators. HNA believes 
that Boeing already received a large number of inspection reporting 
results for its root cause analysis over the past year.
    Southwest Airlines (SWA) asked that the compliance time for the 
reporting requirement be extended to 10 days. SWA stated that the 3-day 
reporting requirement was developed for AD 2019-20-02, Amendment 39-
19755 (84 FR 52754, October 3, 2019). SWA added that the inspection 
program has matured within Boeing and the Model 737-600, -700, -700C, -
800, -900, and -900ER operators, and the reporting requirement of 
initial inspections can be relaxed from 3 to 10 days to reduce the 
burden on airline operations for reporting non-crack findings. 
Additionally, SWA noted that Boeing's airworthiness limitation 
(Document D626A001-9-01) has a requirement to report any crack found 
during these inspections to Boeing within 10 days.
    AIRDO Airlines asked that the reporting requirement be changed from 
3 to 7 days, since the statistical data of the inspection results for 
most of the aging 737NG airplanes has been reported.
    Boeing stated that it has been receiving inspection reports over 
the past year and has accumulated substantial data, and asked that the 
reporting requirement be extended to 10 days.
    Because of the information available from the inspection findings 
that have already been reported to Boeing, the FAA agrees to extend the 
reporting requirements in paragraphs (h) and (k) of this AD to 10 days, 
which would reduce the reporting burden on operators and would provide 
an acceptable level of safety. However, Boeing and the FAA are still 
relying on those inspection results both to provide repair instructions 
when cracks are found and to better understand the nature, cause, and 
extent of the cracking and ultimately develop a terminating action. The 
FAA, therefore, does not agree to extend the reporting requirement to 
30 days.

Request To Provide Credit for Previous Reporting Requirement

    Boeing and AIRDO Airlines asked that reporting as specified in 
paragraph (k) of the proposed AD not be required if an inspection 
report was previously submitted in accordance with AD 2019-20-02 or AD 
2019-22-10.
    The FAA partially agrees with the commenters' request. Although 
reporting per AD 2019-20-02 alone is not adequate for credit with the 
reporting requirement specified in paragraph (k) of this AD, reporting 
per AD 2019-22-10 meets the reporting requirement specified in 
paragraph (k) of this AD. Therefore, the FAA has revised paragraph (k) 
of this AD to specify that a report submitted as required in paragraph 
(h) of this AD is acceptable for compliance with the requirements of 
paragraph (k) of this AD.

Request To Clarify Reporting Requirement

    One commenter asked that the reporting requirement in paragraph (k) 
of the proposed AD be clarified. The commenter stated that inspection 
report example specified in Boeing Multi-Operator Message MOM-MOM-20-
0443-01B (R1), dated June 2, 2020, has columns for repetitive 
inspections. The commenter noted that reporting findings only for the 
initial inspection is required by the proposed AD, and would like 
conformation that reporting findings for repetitive inspections 
thereafter is not required if no cracks are found.
    The FAA acknowledges the commenter's concern and confirms that 
paragraph (k) of this AD requires reporting findings for only the 
initial inspection, and no reporting is required for any repetitive 
inspection regardless of the findings.

Effects of Winglets on Accomplishment of the Proposed Actions

    Aviation Partners Boeing, SWA, and HNA stated that the installation 
of blended or split scimitar winglets per Supplemental Type Certificate 
(STC) ST00830SE does not affect compliance with the proposed actions.
    The FAA agrees with the commenters that STC ST00830SE does not 
affect the accomplishment of the manufacturer's service instructions. 
Operators of airplanes with these winglets do not need to request a 
``change in product'' alternative method of compliance (AMOC) approval 
as specified in 14 CFR 39.17. The FAA has redesignated paragraph (c) of 
the proposed AD as paragraph (c)(1) of this AD, and added paragraph 
(c)(2) to this AD accordingly.

Request To Use Figures To Accomplish the Refined Inspection

    AA asked that it be allowed to use the figures for the refined 
inspection areas in FAA Letter 782-19-14004. AA stated that the global 
AMOC provided in FAA Letter 782-19-14004 and Boeing Multi-Operator 
Message MOM-MOM-19-0536-01B, dated September 30, 2019, is referenced in 
Boeing Multi-Operator Message MOM-MOM-20-0443-01B (R1), dated June 2, 
2020; however, it is not mentioned in the proposed AD.
    The FAA partially agrees with the commenter's request. Paragraph 
(n)(5) of this AD states that AMOCs approved previously for AD 2019-22-
10, which

[[Page 23597]]

include the referenced global AMOC, are approved as AMOCs for the 
corresponding provisions of this AD. Therefore, no change to this AD is 
necessary regarding this issue.

Request for Correction of Typographical Error

    Boeing and HNA requested the FAA correct a typographical error for 
the effective date of AD 2019-22-10, which is referenced in paragraph 
(h)(1) of the proposed AD as October 3, 3019, when the correct date is 
October 3, 2019.
    The FAA agrees with the commenters' request. The FAA has corrected 
the effective date of AD 2019-22-10 in paragraph (h)(1) of this AD 
accordingly.

Conclusion

    The FAA reviewed the relevant data, considered the comments 
received, and determined that air safety and the public interest 
require adopting this AD with the changes described previously, and 
minor editorial changes. The FAA has determined that these minor 
changes:
    <bullet> Are consistent with the intent that was proposed in the 
NPRM for addressing the unsafe condition; and
    <bullet> Do not add any additional burden upon the public than was 
already proposed in the NPRM.
    The FAA also determined that these changes will not increase the 
economic burden on any operator or increase the scope of this AD.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Boeing Multi-Operator Message MOM-MOM-20-0443-01B 
(R1), dated June 2, 2020. This service information specifies procedures 
for repetitive detailed inspections for cracking of the left- and 
right-hand outboard chords of the STA 663.75 frame fittings and 
failsafe straps around eight fasteners adjacent to the stringer S-18A 
straps.
    This AD also requires Boeing Multi-Operator Message MOM-MOM-19-
0623-01B, dated November 5, 2019, which the Director of the Federal 
Register approved for incorporation by reference as of November 13, 
2019 (84 FR 61533, November 13, 2019).
    This AD also requires Boeing Multi-Operator Message MOM-MOM-19-
0536-01B, dated September 30, 2019, which the Director of the Federal 
Register approved for incorporation by reference as of October 3, 2019 
(84 FR 52754, October 3, 2019).
    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 the ADDRESSES section.

Interim Action

    The FAA considers this AD interim action. The inspection reports 
that are required by this AD will enable the manufacturer to obtain 
better insight into the nature, cause, and extent of the cracking, and 
eventually to develop final action to address the unsafe condition. 
Once final action has been identified, the FAA might consider further 
rulemaking.

Costs of Compliance

    The FAA estimates that this AD affects 1,911 airplanes of U.S. 
registry. The FAA estimates the following costs to comply with this AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                 Cost on U.S.
              Action                    Labor cost        Parts cost      Cost per product        operators
----------------------------------------------------------------------------------------------------------------
Inspection (retained action from   1 work-hour x $85                $0  $85 per inspection   $162,435 per
 AD 2019-22-10).                    per hour = $85 per                   cycle.               inspection cycle.
                                    inspection cycle.
Reporting (retained action from    1 work-hour x $85                 0  $85................  $162,435.
 AD 2019-22-10).                    per hour = $85.
Inspection (new action)..........  1 work-hour x $85                 0  $85 per inspection   $162,435 per
                                    per hour = $85 per                   cycle.               inspection cycle.
                                    inspection cycle.
Reporting (new action)...........  1 work-hour x $85                 0  $85................  $162,435.
                                    per hour = $85.
----------------------------------------------------------------------------------------------------------------

    The FAA has received no definitive data that would enable the 
agency to provide cost estimates for the on-condition actions specified 
in this AD.

Paperwork Reduction Act

    A federal agency may not conduct or sponsor, and a person is not 
required to respond to, nor shall a person be subject to penalty for 
failure to comply with a collection of information subject to the 
requirements of the Paperwork Reduction Act unless that collection of 
information displays a current valid OMB control number. The control 
number for the collection of information required by this AD is 2120-
0056. The paperwork cost associated with this AD has been detailed in 
the Costs of Compliance section of this document and includes time for 
reviewing instructions, as well as completing and reviewing the 
collection of information. Therefore, all reporting associated with 
this AD is mandatory. Comments concerning the accuracy of this burden 
and suggestions for reducing the burden should be directed to 
Information Collection Clearance Officer, Federal Aviation 
Administration, 10101 Hillwood Parkway, Fort Worth, TX 76177-1524.

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

    The FAA has determined that 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

[[Page 23598]]

    (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.

Adoption of 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:
0
a. Removing Airworthiness Directive 2019-22-10, Amendment 39-19789 (84 
FR 61533, November 13, 2019); and
0
b. Adding the following new airworthiness directive:

2021-09-06 The Boeing Company: Amendment 39-21519; Docket No. FAA-
2020-0789; Project Identifier AD-2020-00849-T.

(a) Effective Date

    This airworthiness directive (AD) is effective June 8, 2021.

(b) Affected ADs

    This AD replaces AD 2019-22-10, Amendment 39-19789 (84 FR 61533, 
November 13, 2019) (AD 2019-22-10).

(c) Applicability

    (1) This AD applies to all The Boeing Company Model 737-600, -
700, -700C, -800, -900, and -900ER series airplanes, certificated in 
any category.
    (2) Installation of Supplemental Type Certificate (STC) 
ST00830SE does not affect the ability to accomplish the actions 
required by this AD. Therefore, for airplanes on which STC ST00830SE 
is installed, a ``change in product'' alternative method of 
compliance (AMOC) approval request is not necessary to comply with 
the requirements of 14 CFR 39.17.

(d) Subject

    Air Transport Association (ATA) of America Code 53, Fuselage.

(e) Unsafe Condition

    This AD was prompted by reports of cracking discovered in the 
station (STA) 663.75 frame fitting outboard chords and failsafe 
straps adjacent to the stringer S-18A straps and a determination 
that the initial inspection threshold for certain airplanes and the 
repetitive inspection interval specified in AD 2019-22-10 are 
inadequate to address the cracking in a timely manner. The FAA is 
issuing this AD to address cracking in the STA 663.75 frame fitting 
outboard chords and failsafe straps adjacent to the stringer S-18A 
straps, which could result in failure of a Principal Structural 
Element (PSE) to sustain limit load. This condition could adversely 
affect the structural integrity of the airplane and result in loss 
of control of the airplane.

(f) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

(g) Retained Inspection and Corrective Action, With No Changes

    This paragraph restates the requirements of paragraph (g) of AD 
2019-22-10, with no changes. At the earlier of the times specified 
in paragraphs (g)(1) and (2) of this AD: Do a detailed inspection 
for cracking of the left- and right-hand side outboard chords of the 
STA 663.75 frame fittings and failsafe straps adjacent to the 
stringer S 18A straps, in accordance with Boeing Multi-Operator 
Message MOM-MOM-19-0536-01B, dated September 30, 2019. If any crack 
is found, repair before further flight using a method approved in 
accordance with the procedures specified in paragraph (n) of this 
AD. Repeat the inspection thereafter at intervals not to exceed 
3,500 flight cycles until the initial inspection required by 
paragraph (i) of this AD is done.
    (1) Prior to the accumulation of 30,000 total flight cycles, or 
within 7 days after October 3, 2019 (the effective date of AD 2019-
20-02, Amendment 39-19755 (84 FR 52754, October 3, 2019) (AD 2019-
20-02)), whichever occurs later.
    (2) Prior to the accumulation of 22,600 total flight cycles, or 
within 1,000 flight cycles after October 3, 2019 (the effective date 
of AD 2019-20-02), whichever occurs later.

(h) Retained Reporting Requirement, With No Changes

    This paragraph restates the requirements of paragraph (h) of AD 
2019-22-10, with no changes. At the applicable time specified in 
paragraph (h)(1) or (2) of this AD, submit a report of all findings, 
positive and negative, of the initial inspection required by 
paragraph (g) of this AD. Submit the report in accordance with 
Boeing Multi-Operator Message MOM-MOM-19-0536-01B, dated September 
30, 2019.
    (1) If the inspection was done on or after October 3, 2019 (the 
effective date of AD 2019-20-02): Submit the report within 10 days 
after the inspection.
    (2) If the inspection was done before October 3, 2019 (the 
effective date of AD 2019-20-02): Submit the report within 10 days 
after October 3, 2019.

(i) Inspection and Corrective Action With Reduced Compliance Times

    Except as specified in paragraph (j) of this AD: At the 
applicable initial compliance time specified in Tables 1 and 2 of 
``Ref I'' of Boeing Multi-Operator Message MOM-MOM-20-0443-01B (R1), 
dated June 2, 2020, do a detailed inspection of the left- and right-
hand side outboard chords of the STA 663.75 frame fittings and 
failsafe straps around eight fasteners adjacent to the stringer S-
18A straps, in accordance with Boeing Multi-Operator Message MOM-
MOM-20-0443-01B (R1), dated June 2, 2020. If any crack is found, 
repair before further flight using a method approved in accordance 
with the procedures specified in paragraph (n) of this AD. Repeat 
the inspection thereafter at the applicable intervals specified in 
Tables 1 and 2 of ``Ref I'' of Boeing Multi-Operator Message MOM-
MOM-20-0443-01B (R1), dated June 2, 2020. Accomplishing the initial 
inspection required by this paragraph or an initial inspection 
specified in Boeing Multi-Operator Message MOM-MOM-19-0623-01B, 
dated November 5, 2019, terminates the inspections required by 
paragraph (g) of this AD.

(j) Exceptions to Service Information Specifications

    Where Boeing Multi-Operator Message MOM-MOM-20-0443-01B (R1), 
dated June 2, 2020, uses the phrase ``the original issue date of 
MOM-MOM-20-0443-01B(R1),'' this AD requires using ``the effective 
date of this AD.''

(k) New Reporting Requirement

    At the applicable time specified in paragraph (k)(1) or (2) of 
this AD, submit a report of all findings, positive and negative, of 
the initial inspection required by paragraph (i) of this AD. Submit 
the report in accordance with MOM-MOM-20-0443-01B (R1), dated June 
2, 2020. A report submitted as specified in paragraph (h) of this AD 
is acceptable for compliance with the requirements of this 
paragraph.
    (1) If the inspection was done on or after the effective date of 
this AD: Submit the report within 10 days after the inspection.
    (2) If the inspection was done before the effective date of this 
AD: Submit the report within 10 days after the effective date of 
this AD.

(l) Special Flight Permit

    Special flight permits may be issued in accordance with 14 CFR 
21.197 and 21.199 to operate the airplane to a location where the 
airplane can be repaired if any crack is found, provided the 
Manager, Seattle ACO Branch, FAA, concurs with issuance of the 
special flight permit. Send requests for concurrence by email to <a href="/cdn-cgi/l/email-protection#dee7f39f9093f38dbbbfaaaab2bbf39f9d91f39f93919df38cbbafabbbadaaad9eb8bfbff0b9b1a8"><span class="__cf_email__" data-cfemail="fac3d7bbb4b7d7a99f9b8e8e969fd7bbb9b5d7bbb7b5b9d7a89f8b8f9f898e89ba9c9b9bd49d958c">[email&#160;protected]</span></a>.

(m) Paperwork Reduction Act Burden Statement

    A federal agency may not conduct or sponsor, and a person is not 
required to respond to, nor shall a person be subject to a penalty 
for failure to comply with a collection of information subject to 
the requirements of the Paperwork Reduction Act unless that 
collection of information displays a current valid OMB Control 
Number. The OMB Control Number for this information collection is 
2120-0056. Public reporting for this collection of information is 
estimated to be approximately 1 hour per response, including the 
time for reviewing instructions, searching existing data sources, 
gathering and maintaining the data needed,

[[Page 23599]]

and completing and reviewing the collection of information. All 
responses to this collection of information are mandatory as 
required by this AD. Send comments regarding this burden estimate or 
any other aspect of this collection of information, including 
suggestions for reducing this burden to Information Collection 
Clearance Officer, Federal Aviation Administration, 10101 Hillwood 
Parkway, Fort Worth, TX 76177-1524.

(n) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Seattle 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 local Flight Standards District 
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 (o) of this AD. Information may be 
emailed to: <a href="/cdn-cgi/l/email-protection#70495d313e3d5d23151104041c155d31333f5d313d3f335d2215010515030403301611115e171f06"><span class="__cf_email__" data-cfemail="20190d616e6d0d73454154544c450d61636f0d616d6f630d7245515545535453604641410e474f56">[email&#160;protected]</span></a>.
    (2) Before using any approved AMOC, notify your appropriate 
principal inspector, or lacking a principal inspector, the manager 
of the local flight standards district office/certificate holding 
district 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, Seattle 
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.
    (4) AMOCs approved previously for AD 2019-20-02 are approved as 
AMOCs for the corresponding provisions of this AD.
    (5) AMOCs approved previously for AD 2019-22-10 are approved as 
AMOCs for the corresponding provisions of this AD.

(o) Related Information

    For more information about this AD, contact Greg Rutar, 
Aerospace Engineer, Airframe Section, FAA, Seattle ACO Branch, 2200 
South 216th St., Des Moines, WA 98198; phone and fax: 206-231-3529; 
email: <a href="/cdn-cgi/l/email-protection#84c3f6e1e3aad6f1f0e5f6c4e2e5e5aae3ebf2"><span class="__cf_email__" data-cfemail="a2e5d0c7c58cf0d7d6c3d0e2c4c3c38cc5cdd4">[email&#160;protected]</span></a>.

(p) 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 this AD specifies otherwise.
    (3) The following service information was approved for IBR on 
June 8, 2021.
    (i) Boeing Multi-Operator Message MOM-MOM-20-0443-01B (R1), 
dated June 2, 2020.
    (ii) [Reserved]
    (4) The following service information was approved for IBR on 
November 13, 2019 (84 FR 61533, November 13, 2019).
    (i) Boeing Multi-Operator Message MOM-MOM-19-0623-01B, dated 
November 5, 2019.
    (ii) [Reserved]
    (5) The following service information was approved for IBR on 
October 3, 2019 (84 FR 52754, October 3, 2019).
    (i) Boeing Multi-Operator Message MOM-MOM-19-0536-01B, dated 
September 30, 2019.
    (ii) [Reserved]
    (6) 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 <a href="https://www.myboeingfleet.com">https://www.myboeingfleet.com</a>.
    (7) 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.
    (8) 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 <a href="/cdn-cgi/l/email-protection#e98f8c8d9b8c8ec7858c8e8885a987889b88c78e869f"><span class="__cf_email__" data-cfemail="6f090a0b1d0a0841030a080e032f010e1d0e41080019">[email&#160;protected]</span></a>, or go to: <a href="https://www.archives.gov/federal-register/cfr/ibr-locations.html">https://www.archives.gov/federal-register/cfr/ibr-locations.html</a>.

    Issued on April 15, 2021.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2021-08849 Filed 5-3-21; 8:45 am]
BILLING CODE 4910-13-P