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[Federal Register Volume 87, Number 11 (Tuesday, January 18, 2022)]
[Rules and Regulations]
[Pages 2525-2527]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-00588]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-0665; Project Identifier AD-2021-00270-T; 
Amendment 39-21848; AD 2021-25-05]
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) 2017-23-
02, which applied to certain The Boeing Company Model 737-200, -200C, -
300, -400, and -500 series airplanes. AD 2017-23-02 required repetitive 
inspections, replacement, and applicable on-condition actions for 
certain fuselage crown skin panels. This AD was prompted by an 
evaluation by the design approval holder indicating that the fuselage 
crown skin panels are subject to widespread fatigue damage. This AD 
retains the actions in AD 2017-23-02, revises certain airplane 
configurations and inspection locations, and adds airplanes to the 
applicability. The FAA is issuing this AD to address the unsafe 
condition on these products.

DATES: This AD is effective February 22, 2022.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of February 22, 
2022.

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 https://www.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 
https://www.regulations.gov by searching for and locating Docket No. 
FAA-2021-0665.

Examining the AD Docket

    You may examine the AD docket at https://www.regulations.gov by 
searching for and locating Docket No. FAA-2021-0665; 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.

FOR FURTHER INFORMATION CONTACT: James Guo, Aerospace Engineer, 
Airframe Section, FAA, Los Angeles ACO Branch, 3960 Paramount 
Boulevard, Lakewood, CA 90712-4137; phone: 562-627-5357; email: 
[email protected].

SUPPLEMENTARY INFORMATION:

Background

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 to supersede AD 2017-23-02, Amendment 39-19096 (82 FR 
52835, November 15, 2017) (AD 2017-23-02). AD 2017-23-02 applied to 
certain The Boeing Company Model 737-200, -200C, -300, -400, and -500 
series airplanes. The NPRM published in the Federal Register on August 
24, 2021 (86 FR 47260). The NPRM was prompted by an evaluation by the 
design approval holder indicating that the fuselage crown skin panels 
are subject to widespread fatigue damage. In the NPRM, the FAA proposed 
to retain the actions in AD 2017-23-02, revise certain airplane 
configurations and inspection locations, and add airplanes to the 
applicability. The FAA is issuing this AD to address cracking in the 
fuselage crown skin panels. Multiple adjacent cracks in the fuselage 
crown skin could link up and lead to decompression or loss of 
structural integrity of the airplane.

Discussion of Final Airworthiness Directive

Comments

    The FAA received a comment from one commenter. The following 
presents the comment received on the NPRM and the FAA's response.

Effect of Winglets on Accomplishment of the Proposed Actions

    Aviation Partners Boeing stated that the installation of winglets 
per Supplemental Type Certificate (STC) ST01219SE does not affect the 
actions specified in the proposed AD.
    The FAA concurs with the commenter. 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 to state that installation of STC 
ST01219SE does not affect the ability to accomplish the actions 
required by this AD. Therefore,

[[Page 2526]]

for airplanes on which STC ST01219SE 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.

Conclusion

    The FAA reviewed the relevant data, considered any comments 
received, and determined that air safety requires adopting this AD as 
proposed. 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 Service Bulletin 737-53A1358, 
Revision 1, dated February 26, 2021. This service information specifies 
procedures for repetitive non-destructive inspections for cracking, 
replacement of certain fuselage crown skin panels, and applicable on-
condition actions. On-condition actions include a general visual 
inspection of certain repairs for any loose or missing fasteners, a low 
frequency eddy current (LFEC) inspection of certain repairs for 
cracking, and repair. 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 143 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.................  Up to 507 work-hours               $0  Up to $43,095 per      Up to $6,162,585 per
                              x $85 per hour = Up                    inspection cycle.      inspection cycle.
                              to $43,095 per
                              inspection cycle.
Replacement................  304 work-hours x $85           95,000  $120,840 per skin      $17,280,120 per skin
                              per hour = $25,840                     panel.                 panel.
                              per skin panel.
----------------------------------------------------------------------------------------------------------------

    The FAA estimates the following costs to do any necessary 
inspections that would be required based on the results of the 
inspection. The FAA has no way of determining the number of aircraft 
that might need these inspections:

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                     Cost per
                    Action                                 Labor cost               Parts cost        product
----------------------------------------------------------------------------------------------------------------
LFEC inspection...............................  1 work-hours x $85 per hour =                 $0             $85
                                                 $85.
General visual inspection.....................  1 work-hour x $85 per hour = $85               0              85
----------------------------------------------------------------------------------------------------------------

    The FAA has received no definitive data on which to base the cost 
estimates for the on-condition repairs specified in this AD.

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:
0
a. Removing Airworthiness Directive (AD) 2017-23-02, Amendment 39-19096 
(82 FR 52835, November 15, 2017); and
0
b. Adding the following new AD:

2021-25-05 The Boeing Company: Amendment 39-21848; Docket No. FAA-
2021-0665; Project Identifier AD-2021-00270-T.

(a) Effective Date

    This airworthiness directive (AD) is effective February 22, 
2022.

[[Page 2527]]

(b) Affected ADs

    This AD replaces AD 2017-23-02, Amendment 39-19096 (82 FR 52835, 
November 15, 2017) (AD 2017-23-02).

(c) Applicability

    (1) This AD applies to The Boeing Company Model 737-100, -200, -
200C, -300, -400, and -500 series airplanes, certificated in any 
category, as identified in Boeing Alert Service Bulletin 737-
53A1358, Revision 1, dated February 26, 2021.
    (2) Installation of Supplemental Type Certificate (STC) 
ST01219SE does not affect the ability to accomplish the actions 
required by this AD. Therefore, for airplanes on which STC ST01219SE 
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 an evaluation by the design approval 
holder indicating that the fuselage crown skin panels are subject to 
widespread fatigue damage. This AD was also prompted by a 
determination that certain airplane configurations and inspection 
locations need to be revised, and that additional airplanes are 
subject to the unsafe condition. The FAA is issuing this AD to 
address cracking in the fuselage crown skin panels. Multiple 
adjacent cracks in the fuselage crown skin could link up and lead to 
decompression or loss of structural integrity of the airplane.

(f) Compliance

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

(g) Actions for Group 43 Airplanes

    For airplanes identified as Group 43 in Boeing Alert Service 
Bulletin 737-53A1358, Revision 1, dated February 26, 2021, within 
120 days after the effective date of this AD, inspect the airplane 
and do all applicable on-condition actions using a method approved 
in accordance with the procedures specified in paragraph (j) of this 
AD

(h) Required Actions for Groups 1 Through 42 Airplanes

    For airplanes identified as Groups 1 through 42 in Boeing Alert 
Service Bulletin 737-53A1358, Revision 1, dated February 26, 2021, 
except as specified by paragraph (i) of this AD: At the applicable 
times specified in paragraph 1.E., ``Compliance,'' of Boeing Alert 
Service Bulletin 737-53A1358, Revision 1, dated February 26, 2021, 
do all applicable actions identified as ``RC'' (required for 
compliance) in, and in accordance with, the Accomplishment 
Instructions of Boeing Alert Service Bulletin 737-53A1358, Revision 
1, dated February 26, 2021. Actions identified as terminating action 
in Boeing Alert Service Bulletin 737-53A1358, Revision 1, dated 
February 26, 2021, terminate the applicable required actions of this 
AD, provided the terminating action is done in accordance with the 
Accomplishment Instructions of Boeing Alert Service Bulletin 737-
53A1358, Revision 1, dated February 26, 2021.

(i) Exceptions to Service Information Specifications

    (1) Where Boeing Alert Service Bulletin 737-53A1358, Revision 1, 
dated February 26, 2021, uses the phrase ``the original issue date 
of this service bulletin,'' this AD requires using ``December 20, 
2017'' (the effective date of AD 2017-23-02).
    (2) Where Boeing Alert Service Bulletin 737-53A1358, Revision 1, 
dated February 26, 2021, specifies contacting Boeing for repair 
instructions or for work instructions, this AD requires doing the 
repair, or doing the work instructions and applicable on-condition 
actions using a method approved in accordance with the procedures 
specified in paragraph (j) of this AD.
    (3) Part 7 of Boeing Alert Service Bulletin 737-53A1358, 
Revision 1, dated February 26, 2021, specifies post-modification 
airworthiness limitation inspections in compliance with 14 CFR 
25.571(a)(3) at the modified locations to support compliance with 14 
CFR 121.1109(c)(2) or 129.109(b)(2). Although Part 7 is identified 
as RC, this AD does not require accomplishment of Part 7. As 
airworthiness limitations, these inspections are required by 
maintenance and operational rules. It is, therefore, unnecessary to 
mandate them in this AD. Deviations from these inspections require 
FAA approval, but do not require an AMOC.

(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 Related Information. 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.
    (4) AMOCs approved for AD 2017-23-02 are approved as AMOCs for 
the corresponding provisions of Boeing Alert Service Bulletin 737-
53A1358, Revision 1, dated February 26, 2021, that are required by 
paragraph (h) of this AD.
    (5) Except as specified by paragraph (i)(2) of this AD: For 
service information that contains steps that are labeled as Required 
for Compliance (RC), the provisions of paragraphs (j)(5)(i) and (ii) 
of this AD apply.
    (i) The steps labeled as RC, including substeps under an RC step 
and any figures identified in an RC step, must be done to comply 
with the AD. If a step or substep is labeled ``RC Exempt,'' then the 
RC requirement is removed from that step or substep. An AMOC is 
required for any deviations to RC steps, including substeps and 
identified figures.
    (ii) Steps not labeled as RC may be deviated from using accepted 
methods in accordance with the operator's maintenance or inspection 
program without obtaining approval of an AMOC, provided the RC 
steps, including substeps and identified figures, can still be done 
as specified, and the airplane can be put back in an airworthy 
condition.

(k) Related Information

    For more information about this AD, contact James Guo, Aerospace 
Engineer, Airframe Section, FAA, Los Angeles ACO Branch, 3960 
Paramount Boulevard, Lakewood, CA 90712-4137; phone: 562-627-5357; 
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 Service Bulletin 737-53A1358, Revision 1, dated 
February 26, 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; internet https://www.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 [email protected], or go to: https://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued on November 30, 2021.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2022-00588 Filed 1-14-22; 8:45 am]
BILLING CODE 4910-13-P
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