[Federal Register Volume 88, Number 140 (Monday, July 24, 2023)]
[Proposed Rules]
[Pages 47399-47402]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-15304]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2023-1413; Project Identifier AD-2023-00087-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 certain The Boeing Company Model 737-600, -700, -700C, -800, -900 
and -900ER airplanes. This proposed AD was prompted by reports of 
cracks in the forward galley door cutout forward upper corner bear 
strap. It has been determined that the cracks were caused by high 
operating stresses in the fuselage skin door cutout corner area due to 
stress concentration at the door cutout. This proposed AD would require 
an inspection of the fuselage skin and the bear strap at the forward 
galley door cutout forward upper corner for existing repairs, and 
applicable related investigative and corrective inspections. 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 September 
7, 2023.

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.

[[Page 47400]]

    AD Docket: You may examine the AD docket at regulations.gov under 
Docket No. FAA-2023-1413; 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.
    Material Incorporated by Reference:
     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; website 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 
regulations.gov by searching for and locating Docket No. FAA-2023-1413.

FOR FURTHER INFORMATION CONTACT: Bill Ashforth, Aviation Safety 
Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 206-
231-3520; 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-2023-1413; Project Identifier 
AD-2023-00087-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 Bill 
Ashforth, Aviation Safety Engineer, FAA, 2200 South 216th St., Des 
Moines, WA 98198; phone: 206-231-3520; 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 reports indicating cracks in the forward 
galley door cutout forward upper corner bear strap. The airplanes had 
accumulated between 33,070 and 44,224 total flight cycles at the time 
of the crack findings. The cracks were caused by high operating 
stresses in the fuselage skin door cutout corner area due to stress 
concentration at the door cutout. This condition, if not addressed, 
could result in an undetected crack in the fuselage skin and bear 
strap, and could increase in length until the fuselage skin and bear 
strap severs. If not detected and corrected, a severed fuselage skin 
and bear strap may lead to the inability to sustain limit loads and may 
result in rapid decompression of the fuselage and loss of structural 
integrity of the aircraft.

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 737-53A1407 RB, 
dated December 20, 2022. This service information specifies procedures 
for an external general visual inspection of the fuselage skin at the 
forward galley door cutout forward upper corner for any repair, and 
applicable related investigative and corrective actions. Related 
investigative actions include detailed inspections for cracking of the 
fuselage skin and bear strap. Corrective actions include obtaining and 
following instructions for crack 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.

Proposed AD Requirements in This NPRM

    This proposed AD would require accomplishing the actions specified 
in the service information already described and 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 under Docket No. FAA-
2023-1413.

Costs of Compliance

    The FAA estimates that this AD, if adopted as proposed, would 
affect 1,938 airplanes of U.S. registry. The FAA estimates the 
following costs to comply with this proposed AD:

                                                 Estimated Costs
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                                                                                                Cost on U.S.
              Action                    Labor cost        Parts cost    Cost per product          operators
----------------------------------------------------------------------------------------------------------------
External general visual            0.5 work-hour x $85            $0  $42.50 per            $82,365 per
 inspection for repairs.            per hour = $42.50                  inspection cycle.     inspection cycle.
                                    per inspection
                                    cycle.
External detailed and eddy         3.5 work-hours x $85            0  $197.50.............  $576,555.
 current inspection for cracks.     per hour = $197.50.
External eddy current inspection   4 work-hours x $85              0  $340 per inspection   Up to $658,920 per
 without a quadrupler repair.       per hour = $340 per                cycle.                inspection cycle.
                                    inspection cycle.
External eddy current inspection   4 work-hours x $85              0  $340 per inspection   Up to $658,920 per
 with a quadrupler repair.          per hour = $340 per                cycle.                inspection cycle.
                                    inspection cycle.

[[Page 47401]]

 
Internal eddy current inspection   26 work-hours x $85             0  $2,210..............  $4,282,980.
 for cracks.                        per hour = $2,210.
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    The FAA has received no definitive data on which to base the cost 
estimates for the on-condition repairs or for the alternative 
inspections 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-2023-1413; Project Identifier AD-
2023-00087-T.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by September 7, 2023.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to The Boeing Company Model 737-600, -700, -
700C, -800, -900 and -900ER airplanes, certificated in any category, 
as identified in Boeing Alert Requirements Bulletin 737-53A1407 RB, 
dated December 20, 2022.

(d) Subject

    Air Transport Association (ATA) of America Code 53, Fuselage.

(e) Unsafe Condition

    This AD was prompted by reports of cracks in the forward galley 
door cutout forward upper corner bear strap. The FAA is issuing this 
AD to address cracks in the fuselage skin and bear strap, which 
could increase in length until the fuselage skin and bear strap 
severs. If not detected and corrected, a severed fuselage skin and 
bear strap may lead to the inability of the principal structural 
element (PSE) to sustain limit loads and may result in rapid 
decompression of the fuselage 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 737-53A1407 RB, dated December 20, 2022, 
do all applicable actions identified in, and in accordance with, the 
Accomplishment Instructions of Boeing Alert Requirements Bulletin 
737-53A1407 RB, dated December 20, 2022.

    Note 1 to paragraph (g): Guidance for accomplishing the actions 
required by this AD can be found in Boeing Alert Service Bulletin 
737-53A1407, dated December 20, 2022, which is referred to in Boeing 
Alert Requirements Bulletin 737-53A1407 RB, dated December 20, 2022.

(h) Exceptions to Service Information Specifications

    (1) Where the Compliance Time columns of the tables in the 
``Compliance'' paragraph of Boeing Alert Requirements Bulletin 737-
53A1407 RB, dated December 20, 2022, use the phrase ``the original 
issue date of Requirements Bulletin 737-53A1407 RB,'' this AD 
requires using ``the effective date of this AD.''
    (2) Where Boeing Alert Requirements Bulletin 737-53A1407 RB, 
dated December 20, 2022, 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, AIR-520, Continued Operational Safety 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 paragraph (j) 
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, AIR-
520, Continued Operational Safety 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.

[[Page 47402]]

(j) Related Information

    For more information about this AD, contact Bill Ashforth, 
Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 
98198; phone: 206-231-3520; 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 737-53A1407 RB, dated 
December 20, 2022.
    (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; website 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 protected], or go to: www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued on July 7, 2023.
Michael Linegang,
Acting Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2023-15304 Filed 7-21-23; 8:45 am]
BILLING CODE 4910-13-P