[Federal Register Volume 87, Number 11 (Tuesday, January 18, 2022)]
[Rules and Regulations]
[Pages 2534-2536]
[FR Doc No: 2022-00584]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-0609; Project Identifier AD-2021-00274-T;
Amendment 39-21861; AD 2021-26-03]
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 737-300, -400, and -500 series
airplanes. This AD was prompted by an evaluation by the design approval
holder (DAH) indicating that the frame splice between certain stringers
is subject to widespread fatigue damage (WFD). This AD requires an
inspection of certain fuselage frame splices for existing repairs,
repetitive inspections of certain fuselage frame splices for cracking,
and applicable on-condition actions. 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<PHONE_NUMBER>; 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<PHONE_NUMBER>. It is also available at
https://www.regulations.gov by searching for and locating Docket No.
FAA-2021-0609.

Examining the AD Docket

    You may examine the AD docket at https://www.regulations.gov by
searching for and locating Docket No. FAA-2021-0609; 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: Wayne Ha, Aerospace Engineer, Airframe
Section, FAA, Los Angeles ACO Branch, 3960 Paramount Boulevard,
Lakewood, CA 90712-4137; phone:<PHONE_NUMBER>; fax:<PHONE_NUMBER>; 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 737-300, -400, and -500 series airplanes. The NPRM
published in the Federal Register on August 24, 2021 (86 FR 47255). The
NPRM was prompted by an evaluation by the DAH indicating that the frame
splice between certain stringers is subject to WFD. In the NPRM, the
FAA proposed to require an inspection of certain fuselage frame splices
for existing repairs, repetitive inspections of certain fuselage frame
splices for cracking, and applicable on-condition actions. The FAA is
issuing this AD to address upper frame cracking common to the frame
splice between stringer S-13 and S-14, which could interact with
stringer S-14 skin lap splice lower fastener row cracking in lower skin
and result in an uncontrolled decompression of the airplane and loss of
structural integrity.

Discussion of Final Airworthiness Directive

Comments

    The FAA received comments from Aviation Partners Boeing and Boeing.
The following presents the comments received on the NPRM and the FAA's
response to each comment.

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
accomplishment of the manufacturer's service instructions.
    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, 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.

Request To Add Inspection Method

    Boeing requested that the words ``high frequency eddy current
(HFEC)'' be added to the sentence that describes the repetitive
inspections in the ``Related Service Information under 1 CFR part 51''
section of the proposed AD. Boeing stated that the HFEC inspection
should be mentioned because that is the inspection that mitigates the
unsafe condition.
    The FAA agrees with the request. The requested wording has been
added to the specified section of this final rule.

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 Requirements Bulletin 737-53A1388 RB,
dated October 27, 2020. This service information specifies procedures
for a general visual inspection (GVI) of the fuselage frame splices
between stringer S-13 and S-14 station (STA) 360 to STA 520 and STA
727A to STA 907 for existing repairs, repetitive high frequency eddy
current (HFEC) inspections of the fuselage frame splices between
stringer S-13 and S-14 from STA 360 to STA 520 and STA 727A to STA 907
for cracking, and applicable on-condition actions. On-condition actions
include an open hole HFEC inspection for cracking at all fastener hole
locations where a fastener was removed due to finding a cracked
doubler, repair, or replacement. 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 66 airplanes of U.S.
registry. The FAA estimates the following costs to comply with this AD:

                                                                     Estimated Costs
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                                                                 Parts
               Action                        Labor cost           cost               Cost per product                     Cost on U.S. operators
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Repetitive Inspections..............  Up to 267 work-hours x          $0  Up to $22,695 per inspection cycle....  Up to $1,497,870 per inspection cycle.
                                       $85 per hour = Up to
                                       $22,695 per inspection
                                       cycle.
GVI.................................  2 work-hours x $85 per           0  $170..................................  $11,220.
                                       hour = $170.
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    The FAA has received no definitive data on which to base the cost
estimates for the on-condition actions 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 adding the following new airworthiness
directive:

2021-26-03 The Boeing Company: Amendment 39-21861; Docket No. FAA-
2021-0609; Project Identifier AD-2021-00274-T.

(a) Effective Date

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

(b) Affected ADs

    None.

(c) Applicability

    (1) This AD applies to The Boeing Company Model 737-300, -400,
and -500 series airplanes, certificated in any category, as
identified in Boeing Alert Requirements Bulletin 737-53A1388 RB,
dated October 27, 2020.
    (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 (DAH) indicating that the frame splice between stringer S-13
and S-14 is subject to widespread fatigue damage (WFD). The FAA is
issuing this AD to address upper frame cracking common to the frame
splice between stringer S-13 and S-14, which could interact with
stringer S-14 skin lap splice lower fastener row cracking in lower
skin and result in an uncontrolled decompression of the airplane and
loss of structural integrity.

(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 737-53A1388 RB, dated October 27, 2020,
do all applicable actions identified in, and in accordance with, the
Accomplishment Instructions of Boeing Alert Requirements Bulletin
737-53A1388 RB, dated October 27, 2020.
    Note 1 to paragraph (g): Guidance for accomplishing the actions
required by this AD can be found in Boeing Alert Service Bulletin
737-53A1388, dated October 27, 2020, which is referred to in Boeing
Alert Requirements Bulletin 737-53A1388 RB, dated October 27, 2020.

(h) Exceptions to Service Information Specifications

    (1) Where Boeing Alert Requirements Bulletin 737-53A1388 RB,
dated October 27, 2020, uses the phrase ``the Original Issue date of
Requirements Bulletin 737-53A1388 RB,'' this AD requires using ``the
effective date of this AD,'' except where Alert Requirements
Bulletin 737-53A1388 RB, dated October 27, 2020, uses the phrase
``the Original Issue date of Requirements Bulletin 737-53A1388 RB,''
in a note or flag note.
    (2) Where Boeing Alert Requirements Bulletin 737-53A1388 RB,
dated October 27, 2020, specifies contacting Boeing for repair
instructions or for alternative inspections: This AD requires doing
the repair, or doing the alternative inspections and applicable on-
condition actions using a method approved in accordance with the
procedures specified in paragraph (i) of this AD.

(i) 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.

(j) Related Information

    For more information about this AD, contact Wayne Ha, Aerospace
Engineer, Airframe Section, FAA, Los Angeles ACO Branch, 3960
Paramount Boulevard, Lakewood, CA 90712-4137; phone:<PHONE_NUMBER>;
fax:<PHONE_NUMBER>; email: [email protected].

(k) 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 737-53A1388 RB, dated
October 27, 2020.
    (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<PHONE_NUMBER>; 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<PHONE_NUMBER>.
    (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: https://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued on December 8, 2021.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification
Service.
[FR Doc. 2022-00584 Filed 1-14-22; 8:45 am]
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