[Federal Register Volume 89, Number 186 (Wednesday, September 25, 2024)]
[Proposed Rules]
[Pages 78260-78262]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-21813]


 ========================================================================
 Proposed Rules
                                                 Federal Register
 ________________________________________________________________________
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 This section of the FEDERAL REGISTER contains notices to the public of 
 the proposed issuance of rules and regulations. The purpose of these 
 notices is to give interested persons an opportunity to participate in 
 the rule making prior to the adoption of the final rules.
 
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 

  Federal Register / Vol. 89, No. 186 / Wednesday, September 25, 2024 / 
Proposed Rules  

[[Page 78260]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2024-2315; Project Identifier AD-2023-00537-T]
RIN 2120-AA64


Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for certain The Boeing Company Model 737-800 series airplanes. This 
proposed AD was prompted by a determination that the compliance time 
for the initial ultrasonic inspection required by AD 2019-11-06 is 
insufficient for certain airplanes. This proposed AD would require 
reducing the compliance time for the ultrasonic inspection of the skin 
under the drag link assembly. 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 November 
12, 2024.

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.
    AD Docket: You may examine the AD docket at regulations.gov under 
Docket No. FAA-2024-2315; 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 Boeing material 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 material at the FAA, Airworthiness 
Products Section, Operational Safety Branch, 2200 South 216th St., Des 
Moines, WA.

FOR FURTHER INFORMATION CONTACT: Owen Bley-Male, Aviation Safety 
Engineer, FAA, 2200 South 216th St., Des Moines, WA 98198; phone: 206-
231-3992; 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-2024-2315; Project Identifier 
AD-2023-00537-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 Owen 
Bley-Male, Aviation Safety Engineer, FAA, 2200 South 216th St., Des 
Moines, WA 98198; phone: 206-231-3992; 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 issued AD 2019-11-06, Amendment 39-19652 (84 FR 27193, June 
12, 2019) (AD 2019-11-06) for certain The Boeing Company Model 737-600, 
737-700, 737-700C, 737-800, 737-900, and 737-900ER series airplanes. AD 
2019-11-06 requires ultrasonic inspections of the skin under the drag 
link assembly for cracks and applicable on-condition actions. The FAA 
issued AD 2019-11-06 to address cracking in the station (STA) 540 
bulkhead chord or skin, which could result in the inability of a 
primary structural element to sustain limit load.
    Since issuing AD 2019-11-06, the FAA has received a report that, 
for Model 737-800 series airplanes that have been modified to a 
freighter configuration using Boeing Drawing 800A0003, an evaluation of 
structural stresses using revised stress level calculations found that 
the inspection thresholds required by AD 2019-11-06 were insufficient. 
Those airplanes are subject to additional structural stresses due to 
the modifications done during conversion to a freighter configuration. 
Therefore, the compliance times for the initial inspections required by 
AD 2019-11-06 could be performed on those airplanes after the 
appropriate inspection threshold has passed, which could result in 
undetected cracking in the STA 540 bulkhead chord or skin. The FAA 
determined that, for those airplanes, a reduced compliance time is

[[Page 78261]]

needed to address the unsafe condition. Accomplishing the actions 
required by this proposed AD would replace the initial ultrasonic 
inspections required by paragraph (g) of AD 2019-11-06 for Model 737-
800 airplanes converted to a freighter configuration using Boeing 
Drawing 800A0003.
    This condition, if not addressed, could lead to undetected cracking 
in the STA 540 bulkhead chord or skin, which could result in possible 
rapid decompression and loss of structural integrity 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.

Material Incorporated by Reference Under 1 CFR Part 51

    The FAA reviewed Boeing Alert Service Bulletin 737-53A1368, dated 
February 27, 2018. This material specifies an ultrasonic inspection of 
the skin under the drag link assembly and repair for any cracks; 
repetitive inspections for any cracks, including ultrasonic 
inspections, high frequency eddy current inspections, low frequency 
eddy current inspections, and detailed inspections; and a preventative 
modification if no crack is found.
    The FAA also reviewed Boeing 737-800BCF Airworthiness Limitations, 
D140A006, Revision L, dated April 1, 2021. This material contains 
required inspections for principal structural element items. Section 
5.2.1 of this material identifies the airplanes affected by this 
proposed AD.
    This material 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 reduce the compliance time for the initial 
ultrasonic inspection required by AD 2019-11-06 for Model 737-800 
series airplanes that have been converted to a freighter configuration 
using Boeing Drawing 800A0003.

Costs of Compliance

    The FAA estimates that this AD, if adopted as proposed, would 
affect 18 airplanes of U.S. registry. The FAA estimates the following 
costs to comply with this proposed AD:

                                      Estimated Costs for Required Actions
----------------------------------------------------------------------------------------------------------------
                                                                               Cost per         Cost on U.S.
              Action                     Labor cost          Parts cost        product            operators
----------------------------------------------------------------------------------------------------------------
Initial inspection................  Up to 23 work-hours               $0           $1,955   Up to $35,190.
                                     x $85 per hour =
                                     $1,955.
----------------------------------------------------------------------------------------------------------------

    The FAA estimates the following costs to do any on-condition 
actions that would be required based on the results of the proposed 
inspection. The agency has no way of determining the number of 
airplanes that might need these actions:

                Estimated Costs for On-Condition Actions
------------------------------------------------------------------------
            Labor cost                Parts cost      Cost per product
------------------------------------------------------------------------
Up to 56 work-hours x $85 per             $24,020   Up to $28,780.
 hour = $4,760.
------------------------------------------------------------------------

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-2024-2315; Project Identifier AD-
2023-00537-T.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by November 12, 2024.

[[Page 78262]]

(b) Affected ADs

    This AD affects AD 2019-11-06, Amendment 39-19652 (84 FR 27193, 
June 12, 2019) (AD 2019-11-06).

(c) Applicability

    This AD applies to The Boeing Company Model 737-800 series 
airplanes, certificated in any category, that have been converted to 
a freighter configuration using Boeing Drawing 800A0003 before April 
1, 2021, and are identified as Group A in Section 5.2.1, 
``Effectivity,'' of Boeing 737-800BCF Airworthiness Limitations, 
D140A006, Revision L, dated April 1, 2021.

    Note 1 to paragraph (c): Airplanes with a 737-800BCF designation 
are Model 737-800 series airplanes that have been converted to a 
freighter configuration using Boeing Drawing 800A0003.

(d) Subject

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

(e) Unsafe Condition

    This AD was prompted by a determination that the compliance time 
for the initial ultrasonic inspection of the skin under the drag 
link assembly required by AD 2019-11-06 must be reduced for certain 
airplanes. The FAA is issuing this AD to address cracking found in 
the station (STA) 540 bulkhead chord and skin, which could result in 
the inability of a primary structural element to sustain limit load. 
The unsafe condition, if not addressed, could result in possible 
rapid decompression and loss of structural integrity of the 
airplane.

(f) Compliance

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

(g) Required Actions

    (1) For airplanes identified as Group 1, Configuration 2, 3, 4, 
or 5, or as Group 5 in Boeing Alert Service Bulletin 737-53A1368, 
dated February 27, 2018: At the compliance time specified in 
paragraph (g)(1)(i), (ii), (iii), or (iv) of this AD, whichever 
occurs last, perform an ultrasonic inspection of the skin under the 
drag link assembly in accordance with the Accomplishment 
Instructions, Part 2, of Boeing Alert Service Bulletin 737-53A1368, 
dated February 27, 2018. Do all applicable on-condition actions for 
the Part 2 inspection at the times specified in paragraph 1.E., 
``Compliance,'' of Boeing Alert Service Bulletin 737-53A1368, dated 
February 27, 2018, except where Boeing Alert Service Bulletin 737-
53A1368, dated February 27, 2018, specifies contacting Boeing for 
repair instructions, this AD requires doing the repair using a 
method approved in accordance with paragraph (j) of this AD.
    (i) Before the airplane accumulates 17,000 total flight cycles.
    (ii) Within 5,000 flight cycles after July 17, 2019 (the 
effective date of AD 2019-11-06).
    (iii) Within 12 months after the effective date of this AD.
    (iv) Within 1,000 flight cycles after the effective date of this 
AD.
    (2) For airplanes identified as Group 1, Configuration 1, 3, or 
4 in Boeing Alert Service Bulletin 737-53A1368, dated February 27, 
2018: At the compliance time specified in paragraph (g)(2)(i), (ii), 
(iii), or (iv) of this AD, whichever occurs last, perform an 
ultrasonic inspection of the repair tripler under the drag link 
assembly in accordance with the Accomplishment Instructions, Part 6, 
of Boeing Alert Service Bulletin 737-53A1368, dated February 27, 
2018. Do all applicable on-condition actions for the Part 6 
inspection at the times specified in paragraph 1.E., ``Compliance,'' 
of Boeing Alert Service Bulletin 737-53A1368, dated February 27, 
2018, except where Boeing Alert Service Bulletin 737-53A1368, dated 
February 27, 2018, specifies contacting Boeing for repair 
instructions, this AD requires doing the repair using a method 
approved in accordance with paragraph (j) of this AD.
    (i) Before the airplane accumulates 30,000 total flight cycles.
    (ii) Within 5,000 flight cycles after July 17, 2019 (the 
effective date of AD 2019-11-06).
    (iii) Within 12 months after the effective date of this AD.
    (iv) Within 1,000 flight cycles after the effective date of this 
AD.

(i) Terminating Action for Certain Requirements of AD 2019-11-06

    Accomplishing the actions required by this AD replaces the 
corresponding initial ultrasonic inspections and on-condition 
actions required by paragraph (g) of AD 2019-11-06 for Model 737-800 
airplanes converted to a freighter configuration using Boeing 
Drawing 800A0003 only.

(j) 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 (k) 
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.

(k) Related Information

    For more information about this AD, contact Owen Bley-Male, 
Aviation Safety Engineer, FAA, 2200 South 216th St., Des Moines, WA 
98198; phone: 206-231-3992; email: [email protected].

(l) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference of the material listed in this paragraph 
under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this material as applicable to do the actions 
required by this AD, unless the AD specifies otherwise.
    (i) Boeing 737-800BCF Airworthiness Limitations, D140A006, 
Revision L, dated April 1, 2021.
    (ii) Boeing Alert Service Bulletin 737-53A1368, dated February 
27, 2018.
    (3) For Boeing material 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 material 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 material at the National Archives and 
Records Administration (NARA). For information on the availability 
of this material at NARA, visit www.archives.gov/federal-register/cfr/ibr-locations or email [email protected].

    Issued on September 19, 2024.
Peter A. White,
Deputy Director, Integrated Certificate Management Division, Aircraft 
Certification Service.
[FR Doc. 2024-21813 Filed 9-24-24; 8:45 am]
BILLING CODE 4910-13-P