Federal Register / Vol. 89, No. 250 / Tuesday, December 31, 2024 / Proposed Rules 107067 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2024–2716; Project 

Identifier AD–2024–00262–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 

737–8, 737–9, and 737–8200 airplanes. 

This proposed AD was prompted by a 

report indicating that certain clip-on 

nuts with primer, in lieu of clip-on nuts 

with cadmium surface finish only 

(without primer), were inadvertently 

used to install the self-bonded saddle 

clamps, which support the fuel tank 

system tubing inside the left main, 

center, and right main fuel tanks. This 

proposed AD would require a general 

visual inspection (GVI) to identify 

affected parts, and applicable oncondition 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 February 14, 

2025. 

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–2024–2716; 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 the Boeing material identified 

in this proposed 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. 

• 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. 

It is also available at regulations.gov 

under Docket No. FAA–2024–2716. 

FOR FURTHER INFORMATION CONTACT: 

James Laubaugh, Aviation Safety 

Engineer, FAA, 2200 South 216th St., 

Des Moines, WA 98198; phone: 206– 

231–3622; email: james.laubaugh@

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 the ADDRESSES section. Include 

‘‘Docket No. FAA–2024–2716; Project 

Identifier AD–2024–00262–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 James Laubaugh, 

Aviation Safety Engineer, FAA, 2200 

South 216th St., Des Moines, WA 98198; 

phone: 206–231–3622; email: 

james.laubaugh@faa.gov. 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 certain clip-on nuts with 

primer, in lieu of clip-on nuts with 

cadmium surface finish only (without 

primer), were inadvertently used to 

install the self-bonded saddle clamps, 

which support the fuel tank system 

tubing inside the left main, center, and 

right main fuel tanks. The self-bonded 

saddle clamps are designed to be 

attached to the structure with clip-on 

nuts with cadmium surface finish only 

(without primer). The cadmium plating 

is an electrically conductive finish and 

bonds the fuel tank system tubing to the 

structure. Each self-bonded saddle 

clamp has two independent and 

redundant bond paths from the fuel 

system tubing to the structure. These 

bond paths are necessary for the 

dissipation of conducted lightning 

current, induced lightning current, and 

electrostatic energy. The clip-on nuts 

with non-conductive primer can 

interrupt or reduce the capability of the 

electrical bond. This condition, if not 

addressed, could disperse lightning and 

electrostatic energy to the structure, 

creating a possible ignition source 

inside a fuel tank and subsequent fuel 

tank explosion. 

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 Special 

Attention Requirements Bulletin 737– 

28–1376 RB, dated May 3, 2024. This 

material specifies procedures for a 

general visual inspection (GVI) of the 

self-bonded saddle clamps installed 

with clip-on nuts to determine whether 

the surface finish is primer or cadmium 

surface finish only (no primer) in the 

left main, center, and right main fuel 

tanks, and applicable on-condition 

actions. The on-condition actions 

include replacing any clip-on nut with 

primer with a clip-on nut that has 


khammond on DSK9W7S144PROD with PROPOSALS
107068 Federal Register / Vol. 89, No. 250 / Tuesday, December 31, 2024 / Proposed Rules 

cadmium surface finish only (no 

primer). 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 the ADDRESSES section. 

Proposed AD Requirements in This 

NPRM 

This proposed AD would require 

accomplishing the actions specified in 

the material already described, except 

for any differences identified as 

exceptions in the regulatory text of this 

proposed AD. This proposed AD would 

also prohibit the installation of affected 

parts. For information on the procedures 

and compliance times, see this material 

at regulations.gov under Docket No. 

FAA–2024–2716. 

Costs of Compliance 

The FAA estimates that this AD, if 

adopted as proposed, would affect 393 

airplanes of U.S. registry. The FAA 

estimates the following costs to comply 

with this proposed AD: 

ESTIMATED COSTS

Action Labor cost Parts cost Cost per 

product 

Cost on 

U.S. 

operators 

GVI ...... 31 work-hours × $85 per hour = $2,635 ................................................................................ $0 $2,635 $1,035,555 

The FAA estimates the following 

costs to do any replacements 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 this 

replacement: 

ON-CONDITION COSTS

Action Labor cost Parts cost Cost per 

product 

Replace clip-on nuts ......................................................... 42 work-hours × $85 per hour = $3,570 .......................... $692 $4,262 

The FAA has included all known 

costs in its cost estimate. According to 

the manufacturer, however, some or all 

of the costs of this proposed AD may be 

covered under warranty, thereby 

reducing the cost impact on affected 

operators. 

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 

■ 1. The authority citation for part 39 

continues to read as follows: 

Authority: 49 U.S.C. 106(g), 40113, 44701. 

§ 39.13 [Amended] 

■ 2. The FAA amends § 39.13 by adding 

the following new airworthiness 

directive: 

The Boeing Company: Docket No. FAA– 

2024–2716; Project Identifier AD–2024– 

00262–T. 

(a) Comments Due Date 

The FAA must receive comments on this 

airworthiness directive (AD) by February 14, 

2025. 

(b) Affected ADs 

None. 

(c) Applicability 

This AD applies to The Boeing Company 

Model 737–8, 737–9, and 737–8200 

airplanes, certificated in any category, as 

identified in Boeing Special Attention 

Requirements Bulletin 737–28–1376 RB, 

dated May 3, 2024. 

(d) Subject 

Air Transport Association (ATA) of 

America Code 28, Fuel. 

(e) Unsafe Condition 

This AD was prompted by a report 

indicating that certain clip-on nuts with 

primer, in lieu of the clip-on nuts with 

cadmium surface finish only (without 

primer), were inadvertently used to install 

the self-bonded saddle clamps, which 

support the fuel tank system tubing inside 

the left main, center, and right main fuel 

tanks. The FAA is issuing this AD to address 

clip-on nuts with the non-conductive primer 

that can interrupt or reduce the capability of 

the electrical bond. The unsafe condition, if 


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Federal Register / Vol. 89, No. 250 / Tuesday, December 31, 2024 / Proposed Rules 107069 

not addressed, could disperse lightning and 

electrostatic energy to the structure, creating 

a possible ignition source inside a fuel tank 

and subsequent fuel tank explosion. 

(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 Special 

Attention Requirements Bulletin 737–28– 

1376 RB, dated May 3, 2024, do all 

applicable actions identified in, and in 

accordance with, the Accomplishment 

Instructions of Boeing Special Attention 

Requirements Bulletin 737–28–1376 RB, 

dated May 3, 2024. 

Note 1 to paragraph (g): Guidance for 

accomplishing the actions required by this 

AD can be found in Boeing Special Attention 

Service Bulletin 737–28–1376, dated May 3, 

2024, which is referred to in Boeing Special 

Attention Requirements Bulletin 737–28– 

1376 RB, dated May 3, 2024. 

(h) Exceptions to Requirements Bulletin 

Specifications 

Where the Compliance Time columns of 

the tables in the ‘‘Compliance’’ paragraph of 

Boeing Special Attention Requirements 

Bulletin 737–28–1376 RB, dated May 3, 2024, 

refer to the original issue date of 

Requirements Bulletin 737–28–1376 RB, this 

AD requires using the effective date 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)(1) of this AD. 

Information may be emailed to: AMOC@

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, 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. 

(j) Related Information 

(1) For more information about this AD, 

contact James Laubaugh, Aviation Safety 

Engineer, FAA, 2200 South 216th St., Des 

Moines, WA 98198; phone: 206–231–3622; 

email: james.laubaugh@faa.gov. 

(2) Material identified in this AD that is not 

incorporated by reference is available at the 

address specified in paragraph (k)(3) of this 

AD. 

(k) 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 Special Attention Requirements 

Bulletin 737–28–1376 RB, dated May 3, 2024. 

(ii) [Reserved] 

(3) For the 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 fr.inspection@nara.gov. 

Issued on December 20, 2024. 

Suzanne Masterson, 

Deputy Director, Integrated Certificate 

Management Division, Aircraft Certification 

Service. 

[FR Doc. 2024–31348 Filed 12–30–24; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2024–2717; Project 

Identifier MCAI–2024–00147–T] 

RIN 2120–AA64 

Airworthiness Directives; Bombardier, 

Inc., Airplanes 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Notice of proposed rulemaking 

(NPRM). 

SUMMARY: The FAA proposes to 

supersede Airworthiness Directive (AD) 

2020–19–13, which applies to certain 

Bombardier, Inc., Model CL–600–1A11 

(600), CL–600–2A12 (601), and CL–600– 

2B16 (601–3A, 601–3R, and 604 

Variants) airplanes. AD 2020–19–13 

requires a check to identify the 

manufacturer and part number of the 

portable oxygen bottle installation, and 

if necessary, modification of the 

portable oxygen bottle installation. 

Since the FAA issued AD 2020–19–13, 

it was determined that four additional 

airplanes are subject to the unsafe 

condition. This proposed AD would 

continue to require the actions specified 

in AD 2020–19–13 and would expand 

the applicability. 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 February 14, 

2025. 

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–2024–2717; 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, the mandatory 

continuing airworthiness information 

(MCAI), any comments received, and 

other information. The street address for 

Docket Operations is listed above. 

Material Incorporated by Reference: 

• For Bombardier material identified 

in this proposed AD, contact 

Bombardier Business Aircraft Customer 

Response Center, 400 Coˆte Vertu Road 

West, Dorval, Que ́bec H4S 1Y9, Canada; 

telephone 514 855 2999; email ac.yul@

aero.bombardier.com; website 

bombardier.com. 

• 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. 

FOR FURTHER INFORMATION CONTACT: 

Brenda Buitrago, Aviation Safety 

Engineer, FAA, 1600 Stewart Avenue, 

Suite 410, Westbury, NY 11590; 

telephone 516–228–7300; email 9-avsnyaco-cos@faa.gov. 

SUPPLEMENTARY INFORMATION: 

Comments Invited 

The FAA invites you to send any 

written relevant data, views, or 


khammond on DSK9W7S144PROD with PROPOSALS