[Federal Register Volume 86, Number 12 (Thursday, January 21, 2021)]
[Proposed Rules]
[Pages 6276-6279]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-01100]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2020-0587; Product Identifier 2020-NM-086-AD]
RIN 2120-AA64


Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Supplemental notice of proposed rulemaking (SNPRM); reopening 
of comment period.

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SUMMARY: The FAA is revising an earlier proposal for all The Boeing 
Company Model 737-100, -200, -200C, -300, -400, and -500 series 
airplanes. This action revises the notice of proposed rulemaking (NPRM) 
by reducing the compliance time for certain airplanes. The FAA is 
proposing this airworthiness directive (AD) to address the unsafe 
condition on these products. Since these actions would impose an 
additional burden over that in the NPRM, the FAA is reopening the 
comment period to allow the public the chance to comment on these 
changes.

DATES: The comment period for the NPRM published in the Federal 
Register on July 28, 2020 (85 FR 45355), is reopened.
    The FAA must receive comments on this SNPRM by March 8, 2021.

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 Boeing service information identified in this SNPRM, contact 
Boeing Commercial Airplanes, Attention: Contractual & Data Services

[[Page 6277]]

(C&DS), 2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA 90740-5600; 
telephone 562-797-1717; internet https://www.myboeingfleet.com.
    For Aviation Partners Boeing service information identified in this 
SNPRM, contact Aviation Partners Boeing, 2811 South 102nd St., Suite 
200, Seattle, WA 98168; phone: 206-830-7699; fax: 206-767-0535; email: 
leng@aviationpartners.com; internet: http://www.aviationpartnersboeing.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. Boeing Alert Requirements Bulletin 737-57A1349 
RB, dated April 14, 2020, is also available on the internet at https://www.regulations.gov by searching for and locating Docket No. FAA-2020-
0587.

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-
0587; 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 SNPRM, any comments received, and other information. The street 
address for Docket Operations is listed above. Comments will be 
available in the AD docket shortly after receipt.

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; fax: 562-627-5210; email: 
wayne.ha@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-2020-0587; Product Identifier 
2020-NM-086-AD'' 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 
the 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 we receive, 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 we receive about this proposed AD.

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 SNPRM 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 SNPRM, 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 SNPRM. Submissions containing CBI should 
be sent to Wayne Ha, Aerospace Engineer, Airframe Section, FAA, Los 
Angeles ACO Branch, 3960 Paramount Boulevard, Lakewood, CA 90712-4137; 
phone: 562-627-5238; fax: 562-627-5210; email: wayne.ha@faa.gov. Any 
commentary that the FAA receives which is not specifically designated 
as CBI will be placed in the public docket for this rulemaking.

Discussion

    The FAA issued an 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 July 28, 2020 (85 FR 45355). The NPRM was prompted by crack 
indications found in the lower aft wing skin bolt holes where the flap 
tracks attach to the track support fitting. The NPRM proposed to 
require repetitive inspections for cracking of the left and right wing, 
lower aft wing skin aft edge, at certain flap track locations, and 
applicable on-condition actions.

Actions Since the NPRM Was Issued

    Since the FAA issued the NPRM, the FAA determined that the 
compliance time should be reduced for airplanes on which Aviation 
Partners Boeing (APB) blended winglets have been installed using 
supplemental type certificate (STC) ST01219SE.

Comments

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

Support for the NPRM

    One commenter, Jesse Smith, agreed with the intent of the NPRM.

Request To Reduce Compliance Time for Certain Airplanes

    APB asked that the FAA revise this AD to reduce the compliance 
times required for accomplishing the specified actions for airplanes 
that have incorporated STC ST01219SE. APB stated that it issued APB 
Alert Service Bulletin AP737C-57-003, dated July 28, 2020, (which 
contains the same actions as those specified in Boeing Alert 
Requirements Bulletin 737-57A1349 RB, dated April 14, 2020, which is 
the source of service information for the actions specified in this 
proposed AD), with reduced compliance times for those airplanes, and, 
if approved by the FAA, could be added to paragraphs (g) and (h) of the 
proposed AD.
    The FAA agrees with the commenter's request, and has reviewed 
Aviation Partners Boeing Alert Service Bulletin AP737C-57-003, dated 
July 28, 2020. The FAA revised paragraph (g) of this proposed AD, 
including adding paragraphs (g)(1) and (2) of this proposed AD. 
Paragraph (g)(2) of this proposed AD specifies, for airplanes on which 
winglets are installed using STC ST01219SE, doing the required actions 
in Boeing Alert Requirements Bulletin 737-57A1349 RB, dated April 14, 
2020, at the compliance times in Aviation Partners Boeing Alert Service 
Bulletin AP737C-57-003, dated July 28, 2020. The FAA has also added 
paragraphs (h)(4) and (5) of this proposed AD to provide exceptions to 
Aviation Partners Boeing Alert Service Bulletin AP737C-57-003, dated 
July 28, 2020.

Request To Clarify Discussion Section

    Boeing asked that the Discussion section of the NPRM be clarified 
by removing ``This condition, if not addressed'' from the description 
of the unsafe condition, and instead starting the sentence with 
``undetected cracking in the lower wing skin could result. . . .'' 
Boeing stated that the term ``this condition,'' is not clearly defined 
and may lead to confusion. Boeing added that Boeing Alert Requirements 
Bulletin 737-57A1349 RB, dated April 14, 2020, describes inspections 
for cracking, and removing that language will more specifically 
indicate the unsafe condition being addressed in the

[[Page 6278]]

referenced service information. Boeing noted that the suggested 
language is also consistent with the language for the unsafe condition 
specified in paragraph (e) of the proposed AD.
    The FAA acknowledges the commenter's request. However, the sentence 
in question is not carried over to this SNPRM. The FAA has not changed 
this AD regarding this issue.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Boeing Alert Requirements Bulletin 737-57A1349 RB, 
dated April 14, 2020, and Aviation Partners Boeing Alert Service 
Bulletin AP737C-57-003, dated July 28, 2020. The service information 
describes procedures for repetitive high frequency eddy current (HFEC) 
inspections for cracking of the left and right wing, lower aft wing 
skin aft edge, at flap track numbers 1, 2, 3, 6, 7, and 8 attachment 
location and applicable on-condition actions. On-condition actions 
include repairing any cracking found. These documents are distinct 
since they apply to different airplane models in different 
configurations.
    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.

FAA's Determination

    The FAA is proposing this AD because the agency evaluated all the 
relevant information and determined the unsafe condition described 
previously is likely to exist or develop in other products of the same 
type design. Certain changes described above expand the scope of the 
NPRM. As a result, the FAA has determined that it is necessary to 
reopen the comment period to provide additional opportunity for the 
public to comment on this SNPRM.

Proposed Requirements of This SNPRM

    This SNPRM would require accomplishing the actions specified in the 
service information described previously. For information on the 
procedures and compliance times, see Boeing Alert Requirements Bulletin 
737-57A1349 RB, dated April 14, 2020, and Aviation Partners Boeing 
Alert Service Bulletin AP737C-57-003, dated July 28, 2020, at https://www.regulations.gov by searching for and locating Docket No. FAA-2020-
0587.

Costs of Compliance

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

                                      Estimated Costs for Required Actions
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                                                                                                 Cost on U.S.
              Action                      Labor cost         Parts cost    Cost per product        operators
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HFEC inspections.................  7 work-hours x $85 per            $0   $595 per            $83,895 per
                                    hour = $595 per                        inspection cycle.   inspection cycle.
                                    inspection cycle.
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    The FAA has received no definitive data that would enable the FAA 
to provide cost estimates for the on-condition actions specified in 
this proposed 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

    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) 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 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-2020-0587; Product Identifier 
2020-NM-086-AD.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by March 8, 2021.

(b) Affected ADs

    None.

(c) Applicability

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

(d) Subject

    Air Transport Association (ATA) of America Code 57, Wings.

(e) Unsafe Condition

    This AD was prompted by crack indications found in the lower aft 
wing skin bolt holes where the flap tracks attach to the track 
support fitting. The FAA is issuing this AD to address undetected 
cracking in the lower wing skin, which could result in the inability 
of the structure to carry limit load, and adversely affect the 
structural integrity of the airplane.

[[Page 6279]]

(f) Compliance

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

(g) Required Actions

    (1) For all airplanes except those identified in paragraph 
(g)(2) of this AD, except as specified in paragraph (h) of this AD, 
at the applicable times specified in the ``Compliance'' paragraph in 
Boeing Alert Requirements Bulletin 737-57A1349 RB, dated April 14, 
2020, do all applicable actions identified in, and in accordance 
with, the Accomplishment Instructions of Boeing Alert Requirements 
Bulletin 737-57A1349 RB, dated April 14, 2020.
    Note 1 to paragraphs (g)(1) and (2): Guidance for accomplishing 
the actions required by this AD can be found in Boeing Alert Service 
Bulletin 737-57A1349, dated April 14, 2020, which is referred to in 
Boeing Alert Requirements Bulletin 737-57A1349 RB, dated April 14, 
2020.
    (2) For airplanes on which Aviation Partners Boeing blended 
winglets are installed using supplemental type certificate (STC) 
ST01219SE: Except as specified in paragraph (h) of this AD, at the 
applicable time in the ``Compliance'' paragraph in Aviation Partners 
Boeing Alert Service Bulletin AP737C-57-003, dated July 28, 2020, do 
all applicable actions identified in, and in accordance with, the 
Accomplishment Instructions of Boeing Alert Requirements Bulletin 
737-57A1349 RB, dated April 14, 2020.

(h) Exceptions to Service Information Specifications

    (1) Where Boeing Alert Requirements Bulletin 737-57A1349 RB, 
dated April 14, 2020, uses the phrase ``the original issue date of 
Requirements Bulletin 737-57A1349 RB,'' this AD requires using ``the 
effective date of this AD.''
    (2) Where Boeing Alert Requirements Bulletin 737-57A1349 RB, 
dated April 14, 2020, specifies contacting Boeing for repair 
instructions: This AD requires doing the repair and applicable on-
condition actions before further flight using a method approved in 
accordance with the procedures specified in paragraph (i) of this 
AD.
    (3) For airplanes identified as Group 1 in Boeing Alert 
Requirements Bulletin 737-57A1349 RB, dated April 14, 2020: Within 
120 days after the effective date of this AD, do actions to correct 
the unsafe condition using a method approved in accordance with the 
procedures specified in paragraph (i) of this AD.
    (4) Where Aviation Partners Boeing Alert Service Bulletin 
AP737C-57-003, dated July 28, 2020, uses the phrase ``the original 
issue date of this service bulletin,'' this AD requires using ``the 
effective date of this AD.''
    (5) Where Aviation Partners Boeing Alert Service Bulletin 
AP737C-57-003, dated July 28, 2020, specifies contacting Boeing for 
repair instructions: This AD requires doing the repair and 
applicable on-condition actions before further flight 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 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 (j)(1) of this AD. Information 
may be emailed to: 9-ANM-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.

(j) 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; fax: 562-627-5210; email: wayne.ha@faa.gov.
    (2) For Boeing 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.
    (3) For Aviation Partners Boeing service information identified 
in this AD, contact Aviation Partners Boeing, 2811 South 102nd St., 
Suite 200, Seattle, WA 98168; phone: 206-830-7699; fax: 206-767-
0535; email: leng@aviationpartners.com; internet: http://www.aviationpartnersboeing.com.
    (4) 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 December 30, 2020.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2021-01100 Filed 1-19-21; 8:45 am]
BILLING CODE 4910-13-P


