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[Federal Register Volume 85, Number 247 (Wednesday, December 23, 2020)]
[Rules and Regulations]
[Pages 83753-83755]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-28270]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2020-0844; Product Identifier 2020-NM-100-AD; Amendment 
39-21364; AD 2020-26-09]
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 all 
The Boeing Company Model 737-100, -200, -200C, -300, -400, and -500 
series airplanes. This AD was prompted by a report of cracks found in 
fastener holes at a certain station of the center wing box. This AD 
requires repetitive external surface high frequency eddy current (HFEC) 
inspections and repetitive external surface ultrasonic inspections; or 
repetitive internal detailed inspections; of a certain station of the 
center wing box for any cracking, and repair if necessary. The FAA is 
issuing this AD to address the unsafe condition on these products.

DATES: This AD is effective January 27, 2021.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of January 27, 
2021.

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 on 
the internet at https://www.regulations.gov by searching for and 
locating Docket No. FAA-2020-0844.

Examining the AD Docket

    You may examine the AD docket on the internet at https://www.regulations.gov by searching for and locating Docket No. FAA-2020-
0844; 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: 562-627-5238; email: [email protected].

SUPPLEMENTARY INFORMATION: 

Discussion

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 by adding an AD that would apply to all The Boeing Company 
Model 737-100, -200, -200C, -300, -400, and -500 series airplanes. The 
NPRM published in the Federal Register on September 22, 2020 (85 FR 
59449). The NPRM was prompted by a report of cracks found in fastener 
holes at a certain station of the center wing box. The NPRM proposed to 
require repetitive external surface HFEC inspections and repetitive 
external surface ultrasonic inspections; or repetitive internal 
detailed inspections; of a certain station of the center wing box for 
any cracking, and repair if necessary.
    The FAA is issuing this AD to address any cracking found in 
fastener holes at the center wing box, which could result in inability 
of a principal structural element to sustain limit load and could 
adversely affect the structural integrity of the airplane.

Comments

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

Support for the NPRM

    Jason Carrig and Boeing stated their support for the NPRM.

Effect of Winglets on Accomplishment of the Proposed Actions

    Aviation Partners Boeing stated that accomplishing 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, 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 the comments 
received, and determined that air safety and the public interest 
require adopting this final rule with the changes described previously 
and minor editorial changes. The FAA has determined that these minor 
changes:
     Are consistent with the intent that was proposed in the 
NPRM for addressing the unsafe condition; and
     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 final 
rule.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Boeing Alert Requirements Bulletin 737-57A1348 RB, 
dated June 1, 2020. The service information describes procedures for 
repetitive external surface HFEC inspections and repetitive external 
surface ultrasonic inspections; or repetitive internal detailed 
inspections; of the center wing box, station 663.75 rear spar, lower 
skin, and lower chord between left buttock line 31.83 and right buttock 
line 31.83, for any cracking, and repair if necessary. This service 
information is reasonably available because the interested parties have 
access to it through their normal course

[[Page 83754]]

of business or by the means identified in the ADDRESSES section.

Costs of Compliance

    The FAA estimates that this AD affects 141 airplanes of U.S. 
registry. The FAA estimates the following costs to comply with this AD:

                                      Estimated Costs for Required Actions
----------------------------------------------------------------------------------------------------------------
                                                                                                 Cost on U.S.
             Action                     Labor cost          Parts cost     Cost per product        operators
----------------------------------------------------------------------------------------------------------------
Repetitive external HFEC and     3 work-hours x $85 per               $0  $255 per            Up to $35,955 per
 external ultrasonic              hour = $255 per                          inspection cycle.   inspection cycle.
 inspections.                     inspection cycle.
Repetitive internal detailed     28 work-hours x $85 per              $0  $2,380 per          Up to $335,580 per
 inspections.                     hour = $2,380 per                        inspection cycle.   inspection cycle.
                                  inspection cycle.
----------------------------------------------------------------------------------------------------------------

    The FAA has received no definitive data that would enable providing 
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.

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 adding the following new airworthiness 
directive:

2020-26-09 The Boeing Company: Amendment 39-21364 ; Docket No. FAA-
2020-0844; Product Identifier 2020-NM-100-AD.

(a) Effective Date

    This AD is effective January 27, 2021.

(b) Affected ADs

    None.

(c) Applicability

    (1) This AD applies to all The Boeing Company Model 737-100, -
200, -200C, -300, -400, and -500 series airplanes, certificated in 
any category.
    (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 57, Wings.

(e) Unsafe Condition

    This AD was prompted by a report of cracks found in fastener 
holes at the center wing box, station 663.75 rear spar, of the lower 
skin located at left buttock line 6.50. The FAA is issuing this AD 
to address any cracking found in fastener holes at the center wing 
box, which could result in inability of a principal structural 
element to sustain limit load and 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 for Group 1 Airplanes

    For airplanes identified as Group 1 in Boeing Alert Requirements 
Bulletin 737-57A1348 RB, dated June 1, 2020: 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 Group 2 Airplanes

    For airplanes identified as Group 2 in Boeing Alert Requirements 
Bulletin 737-57A1348 RB, dated June 1, 2020, except as specified by 
paragraph (i) of this AD: At the applicable times specified in the 
``Compliance'' paragraph of Boeing Alert Requirements Bulletin 737-
57A1348 RB, dated June 1, 2020, do all applicable actions identified 
in, and in accordance with, the Accomplishment Instructions of 
Boeing Alert Requirements Bulletin 737-57A1348 RB, dated June 1, 
2020.

    Note 1 to paragraph (h): Guidance for accomplishing the actions 
required by this AD can be found in Boeing Alert Service Bulletin 
737-57A1348, dated June 1, 2020, which is referred to in Boeing 
Alert Requirements Bulletin 737-57A1348 RB, dated June 1, 2020.

(i) Exceptions to Service Information Specifications

    (1) Where Boeing Alert Requirements Bulletin 737-57A1348 RB, 
dated June 1, 2020, uses the phrase ``the original issue date of 
Requirements Bulletin 737-57A1348 RB,'' this AD requires using ``the 
effective date of this AD,'' except where Boeing Alert Requirements 
Bulletin 737-57A1348 RB, dated June 1, 2020, uses the phrase ``the 
original issue date of Requirements Bulletin 737-57A1348 RB'' in a 
note or flag note.
    (2) Where Boeing Alert Requirements Bulletin 737-57A1348 RB, 
dated June 1, 2020, specifies contacting Boeing for repair 
instructions: This AD requires doing the repair using a method 
approved in

[[Page 83755]]

accordance with the procedures specified in paragraph (j) of this 
AD.

(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 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 (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 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, 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 Wayne Ha, 
Aerospace Engineer, Airframe Section, FAA, Los Angeles ACO Branch, 
3960 Paramount Boulevard, Lakewood, CA 90712-4137; phone: 562-627-
5238; email: [email protected].
    (2) Service information identified in this AD that is not 
incorporated by reference is available at the addresses specified in 
paragraphs (l)(3) and (4) of this AD.

(l) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference (IBR) of the service information listed 
in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this service information as applicable to do 
the actions required by this AD, unless the AD specifies otherwise.
    (i) Boeing Alert Requirements Bulletin 737-57A1348 RB, dated 
June 1, 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 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 December 9, 2020.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2020-28270 Filed 12-22-20; 8:45 am]
BILLING CODE 4910-13-P
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