This section of the FEDERAL REGISTER

contains regulatory documents having general

applicability and legal effect, most of which

are keyed to and codified in the Code of

Federal Regulations, which is published under

50 titles pursuant to 44 U.S.C. 1510.

The Code of Federal Regulations is sold by

the Superintendent of Documents.

Rules and Regulations Federal Register

65305 

Vol. 88, No. 183 

Friday, September 22, 2023 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2022–1250; Project 

Identifier AD–2022–00763–T; Amendment 

39–22490; AD 2023–13–05] 

RIN 2120–AA64 

Airworthiness Directives; The Boeing 

Company Airplanes 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Final rule. 

SUMMARY: The FAA is adopting a new 

airworthiness directive (AD) for all The 

Boeing Company Model 737–600, –700, 

–700C, –800, –900, and –900ER series 

airplanes. This AD was prompted by a 

report indicating fuselage skin lap splice 

cracking was found between stations 

(STA) 767 and STA 787, just below S– 

14R fuselage skin lap splice, where a 

lower skin panel buckle intersected the 

upper skin of the lap splice. Cracking 

was also found just below S–14R 

between STA 747 and STA 767. This 

AD requires an inspection for any repair 

at certain skin lap splices at S–4, S–14, 

and S–24 and depending on the 

configuration, repetitive inspections for 

buckling, wrinkling, or bulging at 

affected skin lap splices and repair, 

repetitive inspections for cracking at 

affected locations common to fuselage 

skin on the left and right sides and 

repair, and alternative inspections and 

on-condition actions. The FAA is 

issuing this AD to address the unsafe 

condition on these products. 

DATES: This AD is effective October 27, 

2023. 

The Director of the Federal Register 

approved the incorporation by reference 

of a certain publication listed in this AD 

as of October 27, 2023. 

ADDRESSES: 

AD Docket: You may examine the AD 

docket at regulations.gov under Docket 

No. FAA–2022–1250; 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 final rule, any comments 

received, and other information. The 

address for Docket Operations is U.S. 

Department of Transportation, Docket 

Operations, M–30, West Building 

Ground Floor, Room W12–140, 1200 

New Jersey Avenue SE, Washington, DC 

20590. 

Material Incorporated by Reference: 

• For service information identified 

in this final rule, 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 under Docket No. FAA– 

2022–1250. 

FOR FURTHER INFORMATION CONTACT: 

Owen Bley-Male, Aviation Safety 

Engineer, FAA, 2200 South 216th St., 

Des Moines, WA 98198; phone: 206– 

231–3992; email: Owen.F.Bley-Male@

faa.gov. 

SUPPLEMENTARY INFORMATION: 

Background 

The FAA issued a notice of proposed 

rulemaking (NPRM) to amend 14 CFR 

part 39 by adding an AD that would 

apply to all The Boeing Company Model 

737–600, –700, –700C, –800, –900, and 

–900ER series airplanes. The NPRM 

published in the Federal Register on 

November 9, 2022 (87 FR 67581). The 

NPRM was prompted by a report 

indicating fuselage skin lap splice 

cracking was found between STA 767 

and STA 787, just below S–14R fuselage 

skin lap splice, where a lower skin 

panel buckle intersected the upper skin 

of the lap splice. Cracking was also 

found just below S–14R between STA 

747 and STA 767. In the NPRM, the 

FAA proposed to require an inspection 

for any repair at certain skin lap splices 

and depending on the configuration, 

repetitive inspections for buckling, 

wrinkling, or bulging at affected skin lap 

splices and repair, repetitive inspections 

for cracking at affected locations 

common to fuselage skin on the left and 

right sides and repair, and alternative 

inspections and on-condition actions. 

The FAA is issuing this AD to address 

cracks, skin buckles, wrinkles, and 

bulges at fuselage longitudinal lap 

splice areas at S–4, S–14 and S–24. This 

condition, if not addressed, could result 

in cracks in fatigue-critical baseline 

structure and the inability of a principal 

structural element to sustain limit loads, 

which could adversely affect the 

structural integrity of the airplane. 

Discussion of Final Airworthiness 

Directive 

Comments 

The FAA received a comment from 

The Air Line Pilots Association, 

International, who supported the NPRM 

without change. 

The FAA received additional 

comments from six commenters, 

including Boeing, Aviation Partners 

Boeing, Delta Air Lines (Delta), 

Southwest Airlines (SWA), United 

Airlines (UAL), and Qantas. The 

following presents the comments 

received on the NPRM and the FAA’s 

response to each comment. 

Effect of Winglets on Accomplishment 

of the Proposed Actions 

Aviation Partners Boeing stated that 

accomplishing Supplemental Type 

Certificate (STC) ST00830SE does not 

affect the actions specified in the 

proposed AD. 

The FAA concurs with the 

commenter. The FAA has redesignated 

paragraph (c) of the proposed AD as 

paragraph (c)(1) of this AD and added 

paragraph (c)(2) to this AD to state that 

installation of STC ST00830SE does not 

affect the ability to accomplish the 

actions required by this AD. Therefore, 

for airplanes on which STC ST00830SE 

is installed, a ‘‘change in product’’ 

alternative method of compliance 

(AMOC) approval request is not 

necessary to comply with the 

requirements of 14 CFR 39.17 

Request To Correct Errors in Service 

Information or Refer to Latest Service 

Information 

Boeing, Delta, SWA, UAL, and Qantas 

requested that the NPRM be revised to 

correct errors in the referenced service 

information. Boeing, SWA, UAL, and 

Qantas requested that the NPRM be 


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65306 Federal Register / Vol. 88, No. 183 / Friday, September 22, 2023 / Rules and Regulations 

revised to refer to a new revision of 

Boeing Special Attention Requirements 

Bulletin 737–53–1399 RB, dated May 

20, 2022. The commenters noted that 

Boeing was drafting a revision to correct 

several errors in the service information. 

Boeing stated that the revision would 

modify a table and several illustrations, 

inspection steps, and footnotes to clarify 

the inspection locations, and revise 

Table 1 in the Accomplishment 

Instructions to correctly specify the 

applicable airplanes. SWA suggested the 

revision would clarify the distinction 

between the detailed visual and nondestructive testing (NDT) inspections 

underneath the lap joint. UAL and SWA 

noted that certain figures incorrectly 

specify to externally inspect an area that 

is not visible externally. UAL added that 

the revision would correct errors in the 

figures related to orientations of 

airplane sections. Delta and Qantas 

noted that Table 1 of the 

Accomplishment Instructions of Boeing 

Special Attention Requirements Bulletin 

737–53–1399 RB, dated May 20, 2022, 

includes the compliance actions for 

Groups 1 through 6 airplanes, but Table 

1 specifies it applies only to Group 1 

airplanes. UAL pointed out that Table 1 

in the Compliance section specifies the 

inspections are applicable to all 

airplanes, which contradicts Table 1 in 

the Accomplishment Instructions of 

Boeing Special Attention Requirements 

Bulletin 737–53–1399 RB, dated May 

20, 2022. 

The FAA agrees with the commenters’ 

request. The FAA has reviewed Boeing 

Special Attention Requirements Bulletin 

737–53–1399 RB, Revision 1, dated 

March 14, 2023, which corrects the 

errors noted by the commenters. Boeing 

Special Attention Requirements Bulletin 

737–53–1399 RB, Revision 1, dated 

March 14, 2023, also combines actions 

for several conditions to remove 

duplicative instructions and revises 

related figures accordingly. These 

revisions allow operators to do all 

applicable actions for their airplane 

models without obtaining an AMOC, 

and do not add additional work. The 

FAA has revised this AD to refer to 

Boeing Special Attention Requirements 

Bulletin 737–53–1399 RB, Revision 1, 

dated March 14, 2023. 

Request To Clarify Inspection Locations 

Boeing requested that the FAA revise 

the Related Service Information Under 1 

CFR part 51 section of the NPRM to 

clarify the inspection locations, 

including whether they are on the right 

(R) or left (L) side of the airplane, and 

applicable airplane models for each 

inspection location. Boeing noted that 

the locations specified in the NPRM 

don’t correspond to the service 

information due to errors in Boeing 

Special Attention Requirements Bulletin 

737–53–1399 RB, dated May 20, 2022. 

The FAA agrees to revise the Related 

Service Information Under 1 CFR part 

51 section for the reasons provided. The 

FAA has revised this section as 

requested. 

Request To Clarify Root Cause of 

Cracking 

Boeing asked that the FAA change a 

sentence in the Background section of 

the NPRM to specify that the skin lap 

splice cracking ‘‘may have been the 

result of incorrect procedures . . .’’ 

rather than ‘‘was the result of incorrect 

procedures . . .’’ Boeing noted that it 

has always stated that the root cause of 

cracking is unknown. 

The FAA agrees that the suggested 

wording provides clarification on the 

root cause. However, the sentence in 

question does not get carried over to the 

final rule. This AD was not changed 

regarding this issue. 

Request To Clarify Number of Reports 

Boeing requested that the FAA revise 

a sentence in the Background section of 

the NPRM to specify that the FAA 

‘‘received a report from Boeing’’ rather 

than ‘‘received reports’’ indicating 

fuselage skin cracking was found. 

Boeing noted that it had only one report 

of crack findings, with only one airplane 

with cracks reported. 

The FAA agrees that the suggested 

wording is more accurate. However, the 

sentence in question does not get 

carried over to the final rule. This AD 

was not changed regarding this issue. 

Request To Remove Reference to 

Widespread Fatigue Damage (WFD) 

Boeing requested that the FAA revise 

the proposed AD to remove reference to 

WFD. Boeing explained that, although 

there was one report of multi-site 

damage within two bays, it does not 

consider this cracking to be a WFD 

issue. Boeing added that, based on its 

reviews of similar manufactured skins 

on other models of Boeing airplanes, 

these skins are not susceptible to WFD. 

Additionally, Boeing proposed revised 

language for the unsafe condition 

sentence in the proposed AD. 

The FAA agrees with the commenter’s 

request. After further review, the FAA 

has determined that a single crack 

finding is not enough to conclusively 

indicate that the unsafe condition is 

related to WFD. However, an unsafe 

condition still exists because cracks in 

fatigue-critical baseline structure and 

the inability of a principal structural 

element to sustain limit loads could 

adversely affect the structural integrity 

of the airplane. The FAA has revised the 

SUMMARY, Background section, and 

paragraph (e) of this AD to remove 

reference to WFD, and revised the 

Background section and paragraph (e) of 

this AD to clarify the unsafe condition. 

Request To Define Skin Buckles, 

Wrinkles, and Bulges 

Qantas requested that the proposed 

AD be revised to provide more precise 

definitions for skin buckles, wrinkles, 

and bulges, including size, orientation, 

origin, and depth as well as whether 

wrinkling is permanent or temporary. 

Qantas noted that skin panels have 

minor imperfections due to production 

assembly processes, but those aren’t 

skin buckles, wrinkles, or bulges. 

Qantas states that what constitutes a 

skin buckle, wrinkle, or bulge could be 

open to interpretation, causing operators 

to perform unnecessary NDT inspection. 

The commenter noted that it found a 

Boeing definition of a buckle and a 

Boeing Service Letter that states 

wrinkling is temporary and will have no 

detrimental long-term effect unless it 

becomes more severe or permanent. The 

commenter added that the Boeing 

Service Letter suggests that you’ll find 

wrinkling in the vicinity of the 

inspection area. Qantas suggested this 

would lead to unnecessary repeat 

inspection on unrepaired areas and 

cause an undue burden. 

The FAA acknowledges the 

commenter’s concern. This terminology 

reflects the suspected root cause of the 

discovered cracking, and possible 

precursors to future cracks. This 

terminology also reflects commonly 

used verbiage for possible structural 

damage, so further explanation is 

unnecessary. However, the FAA notes 

that Boeing Special Attention 

Requirements Bulletin 737–53–1399 RB, 

Revision 1, dated March 14, 2023, states 

that areas of loose paint, discoloration, 

loose fasteners, lap joint separation, or 

disturbed sealant can be indicative of 

areas where a skin buckle, wrinkle, or 

bulge has occurred. Skin buckles, 

wrinkles, or bulges could lead to cracks 

that may result in the inability of a 

principal structural element to sustain 

limit load, which could result in 

reduced structural integrity of the 

airplane and lead to a decompression 

event. Therefore, the follow-on 

inspections for cracks are necessary if 

any skin buckles, wrinkles, or bulges are 

found, regardless of size, origin, depth, 

or other factors. This AD was not 

changed regarding this issue. 


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Federal Register / Vol. 88, No. 183 / Friday, September 22, 2023 / Rules and Regulations 65307 

Request To Revise Certain Compliance 

Times 

Qantas noted that, for certain 

conditions, the NDT inspections must 

be repeated every 600 flight cycles, 

regardless whether any buckle, wrinkle, 

or bulge is found, which is burdensome 

for operators. The FAA infers the 

commenter is requesting an extension of 

the compliance time. 

The FAA disagrees with the 

commenter’s request. In developing the 

compliance times for this AD, the FAA 

considered the recommendations of the 

manufacturer as well as the urgency 

associated with the subject unsafe 

condition. However, under the 

provisions of paragraph (i) of this AD, 

the FAA will consider requests for 

approval of an extension of the 

compliance time if sufficient data are 

submitted to substantiate that the new 

compliance time would provide an 

acceptable level of safety. This AD was 

not changed regarding this issue. 

Request To Clarify Paint Thickness for 

Certain Inspections 

SWA requested clarification regarding 

the acceptable level of paint thickness 

for certain inspections. SWA noted that 

figures 17 through 19 and 28 through 35 

in Boeing Special Attention 

Requirements Bulletin 737–53–1399 RB, 

dated May 20, 2022, indicate that 

subsequent NDT inspections can be 

accomplished with paint in place. SWA 

added that per the 737 NDT Manual Part 

4, 53–30–06, the procedure can only be 

used with paint up to 0.007 inches 

thick. SWA suggested adding this 

guidance in a note, since the repetitive 

inspections occur every 600 flight 

cycles. 

The FAA notes that the suggested 

clarification has been added to a note in 

the applicable figures in Boeing Special 

Attention Requirements Bulletin 737– 

53–1399 RB, Revision 1, dated March 

14, 2023. As previously noted, this AD 

has been revised to refer to Boeing 

Special Attention Requirements Bulletin 

737–53–1399 RB, Revision 1, dated 

March 14, 2023. Therefore, no further 

change to this AD is necessary regarding 

this issue. 

Conclusion 

The FAA reviewed the relevant data, 

considered any comments received, and 

determined that air safety requires 

adopting this AD as proposed. 

Accordingly, the FAA is issuing this AD 

to address the unsafe condition on these 

products. Except for minor editorial 

changes, and any other changes 

described previously, this AD is 

adopted as proposed in the NPRM. 

None of the changes will increase the 

economic burden on any operator. 

Related Service Information Under 1 

CFR Part 51 

The FAA reviewed Boeing Special 

Attention Requirements Bulletin 737– 

53–1399 RB, Revision 1, dated March 

14, 2023. This service information 

specifies procedures for a general visual 

inspection for any repair, any buckle, 

any wrinkle, any bulge, and any 

cracking at skin lap splice at stringers 

S–4R (737–800 Boeing Converted 

Freighter airplanes only), S–14L, S–14R, 

and S–24R (737–600, –700, –700C, 800, 

–900, and –900ER series airplanes only). 

This service information also describes 

procedures, depending on the 

configuration, for repetitive detailed 

inspections for buckling, wrinkling, or 

bulging at unrepaired areas of affected 

lap splices, and repair; repetitive 

detailed, high frequency eddy current 

(HFEC), and ultrasonic (UT) inspections 

for cracking at affected locations 

common to fuselage skin on the left and 

right sides, and repair; and alternative 

inspections and on-condition actions. 

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. 

Costs of Compliance 

The FAA estimates that this AD 

affects 2,462 airplanes of U.S. registry. 

The FAA estimates the following costs 

to comply with this AD: 

ESTIMATED COSTS

Action Labor cost Parts cost Cost per product Cost on U.S. 

operators 

Inspections ... Up to 34 work-hours × $85 per hour = Up to $2,890 

per inspection cycle.

$0 $2,890 per inspection cycle Up to $7,115,180 per inspection cycle. 

The FAA has received no definitive 

data on which to base the cost estimates 

for the on-condition repairs or for the 

alternative inspections and on-condition 

actions specified in this 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 

This AD will not have federalism 

implications under Executive Order 

13132. This AD will 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 that this AD: 

(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 Amendment 

Accordingly, under the authority 

delegated to me by the Administrator, 

the FAA amends 14 CFR part 39 as 

follows: 


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65308 Federal Register / Vol. 88, No. 183 / Friday, September 22, 2023 / Rules and Regulations 

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: 

2023–13–05 The Boeing Company: 

Amendment 39–22490; Docket No. 

FAA–2022–1250; Project Identifier AD– 

2022–00763–T. 

(a) Effective Date 

This airworthiness directive (AD) is 

effective October 27, 2023. 

(b) Affected ADs 

None. 

(c) Applicability 

(1) This AD applies to all The Boeing 

Company Model 737–600, –700, –700C, 

–800, –900, and –900ER series airplanes, 

certificated in any category. 

(2) Installation of Supplemental Type 

Certificate (STC) ST00830SE does not affect 

the ability to accomplish the actions required 

by this AD. Therefore, for airplanes on which 

STC ST00830SE is installed, a ‘‘change in 

product’’ alternative method of compliance 

(AMOC) approval request is not necessary to 

comply with the requirements of 14 CFR 

39.17 

(d) Subject 

Air Transport Association (ATA) of 

America Code 53, Fuselage. 

(e) Unsafe Condition 

This AD was prompted by a report 

indicating fuselage skin lap splice cracking 

was found between stations (STA) 767 and 

STA 787, just below S–14R fuselage skin lap 

splice, where a lower skin panel buckle 

intersected the upper skin of the lap splice. 

Cracking was also found just below S–14R 

between STA 747 and STA 767. The FAA is 

issuing this AD to address cracks, skin 

buckles, wrinkles, and bulges at fuselage 

longitudinal lap splice areas at S–4, S–14 and 

S–24. This condition, if not addressed, could 

result in cracks in fatigue-critical baseline 

structure and the inability of a principal 

structural element to sustain limit loads, 

which could adversely affect the structural 

integrity of the airplane. 

(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 737–53– 

1399 RB, Revision 1, dated March 14, 2023, 

do all applicable actions identified in, and in 

accordance with, the Accomplishment 

Instructions of Boeing Special Attention 

Requirements Bulletin 737–53–1399 RB, 

Revision 1, dated March 14, 2023. 

Note 1 to paragraph (g): Guidance for 

accomplishing the actions required by this 

AD can be found in Boeing Special Attention 

Service Bulletin 737–53–1399 RB, Revision 

1, dated March 14, 2023, which is referred to 

in Boeing Special Attention Requirements 

Bulletin 737–53–1399 RB, Revision 1, dated 

March 14, 2023. 

(h) Exceptions to Service Information 

Specifications 

(1) Where the Compliance Time columns 

of the tables in the ‘‘Compliance’’ paragraph 

of Boeing Special Attention Requirements 

Bulletin 737–53–1399 RB, Revision 1, dated 

March 14, 2023, use the phrase ‘‘the original 

issue date of the Requirements Bulletin 737– 

53–1399 RB,’’ this AD requires using ‘‘the 

effective date of this AD.’’ 

(2) Where Boeing Special Attention 

Requirements Bulletin 737–53–1399 RB, 

Revision 1, dated March 14, 2023, specifies 

contacting Boeing for repair instructions or 

for alternative inspections: This AD requires 

doing the repair and 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)(1) of this AD. 

Information may be emailed to: 9-ANMSeattle-ACO-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, 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 Owen Bley-Male, Aviation Safety 

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

Moines, WA 98198; phone: 206–231–3992; 

email: Owen.F.Bley-Male@faa.gov. 

(2) Service information identified in this 

AD that is not incorporated by reference is 

available at the addresses specified in 

paragraphs (k)(3) and (4) of this AD. 

(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 Special Attention Requirements 

Bulletin 737–53–1399 RB, Revision 1, dated 

March 14, 2023. 

(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; internet 

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, 

fr.inspection@nara.gov, or go to: 

www.archives.gov/federal-register/cfr/ibrlocations.html. 

Issued on June 30, 2023. 

Michael Linegang, 

Acting Director, Compliance & Airworthiness 

Division, Aircraft Certification Service. 

[FR Doc. 2023–20503 Filed 9–21–23; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2023–1884; Project 

Identifier MCAI–2023–00482–A; Amendment 

39–22554; AD 2023–19–04] 

RIN 2120–AA64 

Airworthiness Directives; Aircraft 

Industries, a.s. Airplanes 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Final rule; request for 

comments. 

SUMMARY: The FAA is adopting a new 

airworthiness directive (AD) for all 

Aircraft Industries, a.s. Model L–420, L 

410 UVP–E20, and L 410 UVP–E20 

CARGO airplanes. This AD was 

prompted by reports of the pressure 

plates within the main landing gear 

(MLG) wheel brake unit malfunctioning. 

This AD requires replacing certain MLG 

wheel brake units with serviceable parts 

and prohibits installing an affected part 


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