Federal Register / Vol. 88, No. 237 / Tuesday, December 12, 2023 / Proposed Rules 86069 

AMS has not identified any relevant 

Federal rules that duplicate, overlap, or 

conflict with this proposed rule. 

A small business guide on complying 

with fruit, vegetable, and specialty crop 

marketing agreements and orders may 

be viewed at: https://

www.ams.usda.gov/rules-regulations/ 

moa/small-businesses. Any questions 

about the compliance guide should be 

sent to Richard Lower at the previously 

mentioned address in the FOR FURTHER

INFORMATION CONTACT section. 

After consideration of all relevant 

material presented, including the 

information and recommendations 

submitted by the Committee and other 

available information, USDA has 

determined that this proposed rule is 

consistent with and will effectuate the 

purposes of the Act. 

A 30-day comment period is provided 

to allow interested persons to respond 

to this proposed rule. All written 

comments timely received will be 

considered before a final determination 

is made on this rule. 

List of Subjects in 7 CFR Part 958 

Marketing agreements, Onions, 

Reporting and recordkeeping 

requirements. 

For the reasons set forth in the 

preamble, the Agricultural Marketing 

Service proposes to amend 7 CFR part 

958 as follows: 

PART 958—ONIONS GROWN IN 

CERTAIN DESIGNATED COUNTIES IN 

IDAHO, AND MALHEUR COUNTY, 

OREGON 

■ 1. The authority citation for 7 CFR 

part 958 continues to read as follows: 

Authority: 7 U.S.C. 601–674. 

■ 2. Revise § 958.240 to read as follows: 

§ 958.240 Assessment rate. 

On and after July 1, 2023, an 

assessment rate of $0.07 per 

hundredweight is established for IdahoEastern Oregon onions. 

Erin Morris, 

Associate Administrator, Agricultural 

Marketing Service. 

[FR Doc. 2023–27213 Filed 12–11–23; 8:45 am] 

BILLING CODE P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2023–2234; Project 

Identifier AD–2023–00963–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 all 

The Boeing Company Model 737–600, 

–700, –700C, –800, –900, and –900ER 

series airplanes. This proposed AD was 

prompted by two engine fan blade-out 

(FBO) events that resulted in the 

separation of engine inlet cowl and fan 

cowl parts from the airplane. In one 

event, fan cowl parts damaged the 

fuselage, which caused loss of 

pressurization and subsequent 

emergency descent. This proposed AD 

would require replacing the fasteners on 

the fan cowl support beam hinge fittings 

for certain airplanes and, for all 

airplanes, would require modifying the 

radial restraint assembly and installing 

an external doubler at the starter vent, 

or as an option, installing a serviceable 

fan cowl. This proposed AD would also 

require revising the existing 

maintenance or inspection program, as 

applicable, to incorporate new 

airworthiness limitations. 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 January 26, 

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–2023–2234; 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–2023–2234. 

FOR FURTHER INFORMATION CONTACT: Luis 

Cortez-Muniz, Aviation Safety Engineer, 

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

WA 98198; telephone: 206–231–3958; 

email: luis.a.cortez-muniz@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 ADDRESSES. Include ‘‘Docket No. 

FAA–2023–2234; Project Identifier AD– 

2023–00963–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 


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86070 Federal Register / Vol. 88, No. 237 / Tuesday, December 12, 2023 / Proposed Rules 

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 Luis Cortez-Muniz, 

Aviation Safety Engineer, FAA, 2200 

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

telephone: 206–231–3958; email: 

luis.a.cortez-muniz@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 received two reports of 

engine events that resulted in the 

separation of engine inlet cowl and fan 

cowl parts from the airplane. One event 

occurred in August 2016 on a Boeing 

Model 737–700 series airplane powered 

by a CFM56–7B engine. The left engine 

failed due to the FBO but the airplane 

landed successfully. The second event 

occurred on April 17, 2018, on a Boeing 

Model 737–700 series airplane powered 

by a CFM56–7B engine. In that event, an 

FBO occurrence resulted in the release 

of fan cowl parts and the engine cowling 

departing the airplane. The fan cowl 

parts damaged the fuselage, which 

caused loss of pressurization and 

subsequent emergency descent. 

Although the airplane landed safely, 

there was one passenger fatality. In that 

event, the suspected cause of the FBO 

occurrence was a low-cycle fatigue 

crack in the dovetail of fan blade 

number 13 of engine number 1. The 

broken fan blade hit the engine fan case 

at a critical location causing a 

significant impulse, displacement, and 

imbalance of the fan rotor effecting the 

structural integrity of the engine 

cowling. 

In response to these events, the FAA 

issued two AD actions for the CFM 

International S.A. (CFM) Model 

CFM56–7B engines. The FAA issued 

emergency AD 2018–09–51, 

Amendment 39–19287 (83 FR 23794, 

May 23, 2018) (AD 2018–09–51), which 

requires a one-time ultrasonic 

inspection of the concave and convex 

sides of the fan blade dovetail. The FAA 

also issued AD 2018–26–01, 

Amendment 39–19531 (83 FR 66090, 

December 26, 2018) (AD 2018–26–01), 

which requires initial and repetitive 

inspections of the concave and convex 

sides of the fan blade dovetail to detect 

cracking and replacement of any blades 

found. The FAA issued AD 2018–09–51 

to address fan blade failure due to 

cracking, which could result in an 

engine in-flight shutdown (IFSD), 

uncontained release of debris, damage 

to the engine, damage to the airplane, 

and possible airplane decompression. 

The FAA issued AD 2018–26–01 to 

address failure of the fan blade, which 

could result in the engine inlet cowl 

disintegrating and debris penetrating the 

fuselage, causing a loss of 

pressurization, and prompting an 

emergency descent. 

Since AD 2018–09–51 and AD 2018– 

26–01 were issued, the FAA has 

determined further rulemaking is 

necessary to reduce the probability of 

unsecured nacelle components, should 

an engine fan blade failure occur. As 

evidenced by Exemption No. 19212, 

dated July 13, 2022 (Docket No. FAA– 

2023–2234), Boeing developed 

modifications to the inlet cowl, fan 

cowl, and exhaust nozzle that must be 

accomplished prior to July 31, 2028. 

Boeing petitioned and the FAA later 

agreed to amend Exemption No. 19212 

to 19212A, which added a requirement 

that solutions to address potential 

maintenance errors must be 

incorporated prior to December 31, 

2029. However, to implement these 

design changes, the FAA must issue 

rulemaking to address the unsafe 

condition. 

This proposed AD would address fan 

cowls that are not strengthened, which 

could, in the event of an FBO 

occurrence, depart the nacelle 

potentially damaging a stabilizer, or the 

fan cowl could strike the fuselage and 

window. The unsafe condition, if not 

addressed, could result in loss of control 

of the airplane, or in a rapid 

decompression and hazard to windowseated passengers aft of the wing. 

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 Special 

Attention Requirements Bulletin 737– 

71–1937 RB, dated July 27, 2023. This 

service information specifies procedures 

for replacing, for certain airplanes, the 

fasteners on the fan cowl support beam 

hinge fittings on the left and right 

engine strut, and, for engine 1 and 

engine 2 for all airplanes, modifying the 

radial restraint assembly and installing 

an external doubler at the starter vent, 

or as an option, installing a serviceable 

fan cowl. 

The service information also requires 

revision of the operator’s maintenance 

or inspection program, as applicable, by 

incorporating certain airworthiness 

limitations (AWLs). 

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, except as discussed under 

‘‘Differences Between this Proposed AD 

and the Service Information’’ 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– 

2023–2234. 

This proposed AD would require 

revisions to certain operator 

maintenance documents to include new 

airworthiness limitations. Compliance 

with these limitations is required by 14 

CFR 91.403(c). For airplanes that have 

been previously modified, altered, or 

repaired in the areas addressed by this 

proposed AD, the operator may not be 

able to accomplish the actions described 

in the revisions. In this situation, to 

comply with 14 CFR 91.403(c), the 

operator must request approval for an 

alternative method of compliance 

according to paragraph (j) of this 

proposed AD. 

Differences Between This Proposed AD 

and the Service Information 

Boeing Special Attention 

Requirements Bulletin 737–71–1937 RB, 

dated July 27, 2023, identifies ‘‘System 

Airworthiness Limitation NO. 2—Fan 

Blade Out Conditions,’’ and ‘‘System 

Airworthiness Limitation NO. 3—Fan 

Blade Out Conditions’’ as the 

airworthiness limitations that must be 

incorporated. In addition to those 

system limitations, the FAA has 

determined that ‘‘System Airworthiness 

Limitation NO. 4—Engine Nacelle 

Maintenance Errors’’ must also be 

incorporated as specified in paragraph 

(h) of this proposed AD. System 

Airworthiness Limitation NO. 4 

specifically provides the limitation that 

mandates solutions to maintenance 

errors that must be accomplished prior 

to December 31, 2029, as required by 

Exemption No. 19212A. 


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Federal Register / Vol. 88, No. 237 / Tuesday, December 12, 2023 / Proposed Rules 86071 

Costs of Compliance 

The FAA estimates that this AD, if 

adopted as proposed, would affect 1,979 

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 

Modification and Installation ........ 140 work-hours × $85 per hour = 

$11,900.

$1,400 ........................ $13,300 ...................... $26,320,700. 

Fastener replacement .................. Up to 8 work-hour × $85 per hour 

= $680.

Up to $2,300 .............. Up to $2,980 .............. Up to $5,897,420. 

* The option to install a serviceable fan cowl would cost up to $16,280 per product. 

The FAA has determined that revising 

the existing maintenance or inspection 

program takes an average of 90 workhours per operator, although the agency 

recognizes that this number may vary 

from operator to operator. Since 

operators incorporate maintenance or 

inspection program changes for their 

affected fleet(s), the FAA has 

determined that a per-operator estimate 

is more accurate than a per-airplane 

estimate. Therefore, the agency 

estimates the average total cost per 

operator to be $7,650 (90 work-hours × 

$85 per work-hour). 

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– 

2023–2234; Project Identifier AD–2023– 

00963–T. 

(a) Comments Due Date 

The FAA must receive comments on this 

airworthiness directive (AD) by January 26, 

2024. 

(b) Affected ADs 

None. 

(c) Applicability 

This AD applies to all The Boeing 

Company Model 737–600, –700, –700C, 

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

certificated in any category. 

(d) Subject 

Air Transport Association (ATA) of 

America Code 71, Powerplant. 

(e) Unsafe Condition 

This AD was prompted by two engine fan 

blade-out (FBO) events that resulted in the 

separation of engine inlet cowl and fan cowl 

parts from the airplane. In one event, fan 

cowl parts damaged the fuselage, which 

caused loss of pressurization and 

subsequential emergency descent. The FAA 

is issuing this AD to address fan cowls that 

are not strengthened, which, in the event of 

an FBO occurrence, could depart the nacelle 

potentially damaging a stabilizer, or the fan 

cowl striking the fuselage and window. The 

unsafe condition, if not addressed, could 

result in loss of control of the airplane, or in 

a rapid decompression and hazard to 

window-seated passengers aft of the wing. 

(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 737–71– 

1937 RB, dated July 27, 2023, do all 

applicable actions identified in, and in 

accordance with, the Accomplishment 

Instructions of Boeing Special Attention 

Requirements Bulletin 737–71–1937 RB, 

dated July 27, 2023. 

Note 1 to paragraph (g): Guidance for 

accomplishing the actions required by this 

AD can be found in Boeing Special Attention 

Service Bulletin 737–71–1937, dated July 27, 

2023, which is referred to in Boeing Special 

Attention Requirements Bulletin 737–71– 

1937 RB, dated July 27, 2023. 

(h) Exceptions to Service Information 

Specifications 

(1) Where the service information 

referenced in paragraph (g) of this AD 

specifies contacting Boeing or Collins 

Aerospace for repair instructions: This AD 

requires doing the repair before further flight 

using a method approved in accordance with 

the procedures specified in paragraph (j) of 

this AD. 

(2) Where Tables 1 through 4 of Boeing 

Special Attention Requirements Bulletin 

737–71–1937 RB, dated July 27, 2023, specify 

incorporating 737–600/700/700C/800/900/ 

900ER Airworthiness Limitations (AWLs) 

document D626A001–9–01 ‘‘System 

Airworthiness Limitation NO. 2—Fan Blade 


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86072 Federal Register / Vol. 88, No. 237 / Tuesday, December 12, 2023 / Proposed Rules 

Out Conditions’’ and ‘‘System Airworthiness 

Limitation NO. 3—Fan Blade Out 

Conditions’’ into the operators’ maintenance 

program, this AD requires revising the 

existing maintenance or inspection program, 

as applicable, by incorporating the 

information specified in Figure 1 to the 

introductory text of paragraph (h) of this AD 

into the airworthiness limitations within 90 

days after the effective date of this AD, or 

before further flight after accomplishing the 

(Option 1) or (Option 2) actions in Boeing 

Special Attention Requirements Bulletin 

737–71–1937 RB, dated July 27, 2023, 

whichever occurs first. 

Figure 1 to the Introductory Text of 

Paragraph (h)—System Airworthiness 

Limitations 

(i) No Alternative Actions 

After the existing maintenance or 

inspection program has been revised as 

required by paragraph (h)(2) of this AD, no 

alternative actions may be used unless the 

actions are approved as an alternative 

method of compliance (AMOC) in 

accordance with the procedures specified in 

paragraph (j) of this AD. 

(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: 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. 

(k) Related Information 

For more information about this AD, 

contact Luis Cortez-Muniz, Aviation Safety 

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

Moines, WA 98198; telephone: 206–231– 

3958; email: luis.a.cortez-muniz@faa.gov. 

(l) 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 737–71–1937 RB, dated July 27, 

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; 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 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 1, 2023. 

Victor Wicklund, 

Deputy Director, Compliance & Airworthiness 

Division, Aircraft Certification Service. 

[FR Doc. 2023–27100 Filed 12–11–23; 8:45 am] 

BILLING CODE 4910–13–P 


ddrumheller on DSK120RN23PROD with PROPOSALS1EP12DE23.002</GPH>

SYSTEM .AIR.WORTHINESS LIMITATION No. 2 

Fk~ BLADE OUT CONDmONS 

All airaaihnustinstall the following modifications: (l)engine inlets \\iith new spacer design and 

.increased fastener capability (2) fan cowls l\ith new radial testraiut fitting hooks. new radial restraint 

clips. and an external doubler at the starter \'ent (3)f.m cowl support beam fastener changes (except for 

7'57:-900ER. aircraft, bee.use the fan cowl support beam fastener changes are already incmporated). All . aircraftthatha\.re not inootporated these modifkationscannotoperatepast July 31, 2028 unless upgraded 

to new hardware that is fully compliant to §§25.901(e) and AppendixK25.1.1 to Part 25. Boeing u,ill 

• release all sen.ice data to allow retrofit of hardware updates to the CFM56-1B nacelle prior to that date~ 

SYSTEM AIRWORTHINESS LIMITATION No. 3 

FAN BLADE OUT CONDmONS 

All aircraft delivered without the Penonnance Improvement Package (PIP) must install engine exhaust 

nozzle stmctura1 stiffening: elements. All aircraft that have not incorporated these modifications cannot 

operate past July 31~ 2028 unless upgraded to new hardware that is fully compliant to §§25.901{c) and 

. Appendix K.25:1.1 to Part 25. Boeing "'ill release all sen'ice data to allow retrofit of hardware updates to 

the CFM56-1Bnacelle prior to that date. 

SYSTEMAIR.WORTHINESSLIMITATION No. 4 

ENG~"E NACELLE :MAINTENANCE ERR.ORS 

. .\.11 aircraft must incmporate solutions to address potential maintenance errors. e.g., the failure to .. 

completely latch the f.m cowl or the fan cowl integrated drive generator (IDG) door. All aircraft that have 

not incotpOrated dlanges to become fully compliant 'INith §§25.901(c) and AppendixK.2S;Lt to Part 25 

cannot be operated past December 31~ 20.29.