[Federal Register Volume 87, Number 173 (Thursday, September 8, 2022)]
[Proposed Rules]
[Pages 54922-54925]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-19271]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2022-1061; Project Identifier AD-2022-00441-T]
RIN 2120-AA64


Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for all The Boeing Company Model 737-100, -200, -200C, -300, -400, and 
-500 series airplanes. This proposed AD was prompted by a report 
indicating that a crack was found in one of the holes of the wing rear 
spar lower chord at the main landing gear (MLG) aft fitting at a 
certain wing buttock line (WBL). This proposed AD would require 
repetitive open hole high frequency eddy current (HFEC) inspections or 
surface HFEC and ultrasonic (UT) inspections for cracking of the wing 
rear spar lower chord at the MLG aft fitting at a certain WBL, and 
applicable on-condition actions. The FAA is proposing this AD to 
address the unsafe condition on these products.

DATES: The FAA must receive comments on this proposed AD by October 24, 
2022.

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 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 service information identified in this NPRM, 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 myboeingfleet.com. 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

[[Page 54923]]

this material at the FAA, call 206-231-3195. It is also available at 
regulations.gov by searching for and locating Docket No. FAA-2022-1061.

Examining the AD Docket

    You may examine the AD docket at regulations.gov by searching for 
and locating Docket No. FAA-2022-1061; 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 NPRM, any comments 
received, and other information. The street address for Docket 
Operations is listed above.

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:

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-2022-1061; Project Identifier 
AD-2022-00441-T'' 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 
this 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 received, without change, to 
regulations.gov, including any personal information you provide. The 
agency will also post a report summarizing each substantive verbal 
contact received about this NPRM.

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 NPRM 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 NPRM, 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 NPRM. 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; 
email: [email protected]. Any commentary that the FAA receives that is 
not specifically designated as CBI will be placed in the public docket 
for this rulemaking.

Background

    The FAA has received a report indicating that cracking was found in 
one of the holes of the wing rear spar lower chord at the MLG aft 
fitting at WBL 157 on a Model 737-400 airplane. The airplane had 
accumulated 52,936 total flight hours and 43,944 total flight cycles at 
the time of the crack finding. Cracking in the rear spar lower chord at 
a fastener common to the MLG aft support fitting at WBL 157, if not 
addressed, could result in the inability of the rear spar lower chord 
to sustain limit loads, resulting in reduced structural integrity of 
the airplane and possible loss of control of the airplane.

FAA's Determination

    The FAA is issuing this NPRM after determining that the unsafe 
condition described previously is likely to exist or develop on other 
products of the same type design.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Boeing Alert Requirements Bulletin 737-57A1353 RB, 
dated February 10, 2022. This service information specifies procedures 
for repetitive open hole HFEC inspections or surface HFEC and UT 
inspections for cracking, and applicable on-condition actions. On-
condition actions include installing fasteners 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.

Explanation of Applicability

    Model 737 airplanes having line numbers 1 through 291 have a limit 
of validity (LOV) of 34,000 total flight cycles, and the actions 
proposed in this NPRM, as specified in Boeing Alert Requirements 
Bulletin 737-57A1353 RB, dated February 10, 2022, would be required at 
a compliance time occurring after that LOV. Although operation of an 
airplane beyond its LOV is prohibited by 14 CFR 121.1115 and 129.115, 
this NPRM would include those airplanes in the applicability so that 
these airplanes are tracked in the event the LOV is extended in the 
future.

Proposed AD Requirements in This NPRM

    This proposed AD would require accomplishing the actions specified 
in the service information already described, except for any 
differences identified as exceptions in the regulatory text of this 
proposed AD. For information on the procedures and compliance times, 
see this service information at regulations.gov by searching for and 
locating Docket No. FAA-2022-1061.

Costs of Compliance

    The FAA estimates that this AD, if adopted as proposed, would 
affect 69 airplanes of U.S. registry. The FAA estimates the following 
costs to comply with this proposed AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                            Parts                               Cost on U.S.
              Action                      Labor cost         cost      Cost per product          operators
----------------------------------------------------------------------------------------------------------------
Open hole HFEC inspection.........  30 work-hours x $85         $0  $2,550 per inspection  Up to $175,950 per
                                     per hour = $2,550               cycle.                 inspection cycle.
                                     per inspection cycle.
Surface HFEC/UT inspections.......  4 work-hours x $85           0  $340 per inspection    Up to $23,460 per
                                     per hour = $340 per             cycle.                 inspection cycle.
                                     inspection cycle.
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[[Page 54924]]

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

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                     Cost per
                    Action                                 Labor cost               Parts cost        product
----------------------------------------------------------------------------------------------------------------
Install fasteners.............................  1 work-hour x $85 per hour = $85            * $0             $85
----------------------------------------------------------------------------------------------------------------
* The FAA anticipates no parts cost because operators will have spare fasteners in stock.

    The FAA has received no definitive data on which to base the cost 
estimates for the on-condition repairs 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) Would not affect intrastate aviation in Alaska, and
    (3) Would 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-2022-1061; Project Identifier AD-
2022-00441-T.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by October 24, 2022.

(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 a report indicating that a crack was 
found in one of the holes of the wing rear spar lower chord at the 
main landing gear (MLG) aft fitting at wing buttock line (WBL) 157. 
The FAA is issuing this AD to address cracking in the rear spar 
lower chord at a fastener common to the MLG aft support fitting. 
This condition, if not addressed, could result in the inability of 
the rear spar lower chord to sustain limit loads, resulting in 
reduced structural integrity of the airplane and possible loss of 
control 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 737-57A1353 RB, dated February 10, 2022: 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 and Group 3 Airplanes

    For airplanes identified as Group 2 and Group 3 in Boeing Alert 
Requirements Bulletin 737-57A1353 RB, dated February 10, 2022: 
Except as specified by paragraph (h) of this AD, at the applicable 
times specified in the ``Compliance'' paragraph of Boeing Alert 
Requirements Bulletin 737-57A1353 RB, dated February 10, 2022, do 
all applicable actions identified in, and in accordance with, the 
Accomplishment Instructions of Boeing Alert Requirements Bulletin 
737-57A1353 RB, dated February 10, 2022.
    Note 1 to paragraph (h): Guidance for accomplishing the actions 
required by this AD can be found in Boeing Alert Service Bulletin 
737-57A1353, dated February 10, 2022, which is referred to in Boeing 
Alert Requirements Bulletin 737-57A1353 RB, dated February 10, 2022.

(i) Exceptions to Service Information Specifications

    (1) Where the Compliance Time columns of the tables in the 
``Compliance'' paragraph of Boeing Alert Requirements Bulletin 737-
57A1353 RB, dated February 10, 2022, use the phrase ``the original 
issue date of Requirements Bulletin 737-57A1353 RB,'' this AD 
requires using ``the effective date of this AD.''
    (2) Where Boeing Alert Requirements Bulletin 737-57A1353 RB, 
dated February 10, 2022, specifies contacting Boeing for repair 
instructions: This AD requires doing the repair using a method 
approved in 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 responsible Flight Standards 
Office, as appropriate. If sending information directly to the 
manager of the

[[Page 54925]]

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 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.

(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) 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 myboeingfleet.com. 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 August 19, 2022.
Christina Underwood,
Acting Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2022-19271 Filed 9-7-22; 8:45 am]
BILLING CODE 4910-13-P