Federal Register / Vol. 90, No. 19 / Thursday, January 30, 2025 / Proposed Rules 8505 

Issued on January 23, 2025. 

Steven W. Thompson, 

Acting Deputy Director, Compliance & 

Airworthiness Division, Aircraft Certification 

Service. 

[FR Doc. 2025–01949 Filed 1–29–25; 8:45 am] 

BILLING CODE 4910–13–C 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2024–2721; Project 

Identifier AD–2024–00610–E] 

RIN 2120–AA64 

Airworthiness Directives; General 

Electric Company Engines 

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 General Electric Company (GE) 

Model CF6–80E1A2, CF6–80E1A3, 

CF6–80E1A4, and CF6–80E1A4/B 

engines. This proposed AD was 

prompted by a manufacturer 

investigation that revealed certain highpressure turbine (HPT) stage 1 and HPT 

stage 2 disks were manufactured from 

powder metal material suspected to 

contain iron inclusion. This proposed 

AD would require replacement of 

affected HPT stage 1 and HPT stage 2 

disks with parts eligible for installation. 

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 March 17, 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–2024–2721; 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. 

FOR FURTHER INFORMATION CONTACT: 

Alexei Marqueen, Aviation Safety 

Engineer, FAA, 2200 South 216th Street, 

Des Moines, WA 98198; phone: (781) 

238–7178; email: alexei.t.marqueen@

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–2024–2721; Project 

Identifier AD–2024–00610–E’’ 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 revise 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 Alexei Marqueen, 

Aviation Safety Engineer, FAA, 2200 

South 216th Street, Des Moines, WA 

98198. Any commentary that the FAA 

receives which is not specifically 

designated as CBI will be placed in the 

public docket for this rulemaking. 

Background 

The FAA was notified by the 

manufacturer of the detection of iron 

inclusion in an HPT stage 2 disk 

manufactured from the same powder 

metal material used to manufacture 

certain HPT stage 1 and HPT stage 2 

disks for GE Model CF6–80E1A2, CF6– 

80E1A3, CF6–80E1A4, and CF6– 

80E1A4/B engines. Further investigation 

by the manufacturer revealed that the 

iron inclusion is attributed to 

deficiencies in the manufacturing 

process and may cause reduced material 

properties and a lower fatigue life 

capability, which may result in 

premature fracture and uncontained 

failure. The manufacturer also informed 

the FAA that additional risk 

assessments determined that there were 

no failed events associated with the 

discovery of this iron inclusion material 

on these engines, but concluded that 

replacement of the affected HPT stage 1 

and HPT stage 2 disks is necessary to 

prevent any future failed events. The 

exposure of certain HPT stage 1 and 

HPT stage 2 disks to iron inclusion, if 

not addressed, could result in 

uncontained debris release, damage to 

the engine, and damage to 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. 

Proposed AD Requirements in This 

NPRM 

This proposed AD would require 

replacement of affected HPT stage 1 and 

HPT stage 2 disks with parts eligible for 

installation. Because affected operators 

are already aware of the proposed 

corrective action and have already 

performed the actions proposed in this 

AD, the FAA has determined that the 

compliance time to replace the affected 

HPT stage 1 and HPT stage 2 disks 

before further flight is appropriate. 

Costs of Compliance 

The FAA estimates that this AD, if 

adopted as proposed, would affect one 

engine installed on an airplane of U.S. 

registry. 

The FAA estimates the following 

costs to comply with this proposed AD: 


lotter on DSK11XQN23PROD with PROPOSALS1
8506 Federal Register / Vol. 90, No. 19 / Thursday, January 30, 2025 / Proposed Rules 

ESTIMATED COSTS

Action Labor cost Parts cost Cost per 

product 

Cost on U.S. 

operators 

Replace HPT stage 1 disk ..... 8 work-hours × $85 per hour = $680 ............. $1,228,800 (prorated) ............ $1,229,480 $1,229,480 

Replace HPT stage 2 disk ..... 8 work-hours × $85 per hour = $680 ............. $201,600 (prorated) ............... 202,280 202,280 

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: 

General Electric Company: Docket No. FAA– 

2024–2721; Project Identifier AD–2024– 

00610–E. 

(a) Comments Due Date 

The FAA must receive comments on this 

airworthiness directive (AD) by March 17, 

2025. 

(b) Affected ADs 

None. 

(c) Applicability 

This AD applies to General Electric 

Company (GE) Model CF6–80E1A2, CF6– 

80E1A3, CF6–80E1A4, and CF6–80E1A4/B 

engines with an installed high-pressure 

turbine (HPT) stage 1 disk or HPT stage 2 

disk having a part number (P/N) and serial 

number (S/N) identified in Table 1 to 

paragraph (c) of this AD. 

TABLE 1 TO PARAGRAPH (c)—AFFECTED HPT STAGE 1 AND HPT STAGE 2 DISKS

Part name P/N S/N 

HPT stage 1 disk .............................................................. 1863M36G06 ................................................................... GWN0GP27. 

HPT stage 1 disk .............................................................. 1863M36G06 ................................................................... GWN0GPM8. 

HPT stage 1 disk .............................................................. 1863M36G06 ................................................................... GWN0GP26. 

HPT stage 1 disk .............................................................. 1863M36G06 ................................................................... TMT5SW61. 

HPT stage 1 disk .............................................................. 1863M36G06 ................................................................... TMT5SW59. 

HPT stage 1 disk .............................................................. 1863M36G06 ................................................................... TMT5SW64. 

HPT stage 1 disk .............................................................. 1863M36G06 ................................................................... TMT5SW82. 

HPT stage 1 disk .............................................................. 1863M36G06 ................................................................... GWN0GPMG. 

HPT stage 2 disk .............................................................. 1778M72P05 ................................................................... BTB77100. 

HPT stage 2 disk .............................................................. 1778M72P05 ................................................................... MUNLD123. 

HPT stage 2 disk .............................................................. 1778M72P05 ................................................................... MUNLD122. 

HPT stage 2 disk .............................................................. 1778M72P05 ................................................................... MUN5B794. 

HPT stage 2 disk .............................................................. 1778M72P05 ................................................................... BTB77102. 

(d) Subject 

Joint Aircraft System Component (JASC) 

Code 7250, Turbine Section. 

(e) Unsafe Condition 

This AD was prompted by a manufacturer 

investigation that revealed certain HPT stage 

1 and HPT stage 2 disks were subject to iron 

inclusion introduced during the 

manufacturing process. The FAA is issuing 

this AD to prevent fracture and potential 

uncontained failure of certain HPT stage 1 

and HPT stage 2 disks. The unsafe condition, 

if not addressed, could result in uncontained 

debris release, damage to the engine, and 

damage to the airplane. 

(f) Compliance 

Comply with this AD within the 

compliance times specified, unless already 

done. 

(g) Required Actions 

(1) Before further flight after the effective 

date of this AD, remove any affected HPT 

stage 1 disk having P/N 1863M36G06 and S/ 

N GWN0GP27 from service and replace with 

a part eligible for installation. 

(2) Before further flight after the effective 

date of this AD, remove any affected HPT 

stage 2 disk having P/N 1778M72P05 and S/ 

N BTB77100 from service and replace with 

a part eligible for installation. 


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Federal Register / Vol. 90, No. 19 / Thursday, January 30, 2025 / Proposed Rules 8507 

(3) For affected HPT stage 1 disks 

identified in Table 1 to paragraph (c) of this 

AD that are not included in paragraph (g)(1) 

of this AD, at the next piece part exposure 

or before the affected HPT stage 1 disk 

exceeds 8,600 cycles since new (CSN), 

whichever occurs first after the effective date 

of this AD, remove the affected HPT stage 1 

disk from service and replace with a part 

eligible for installation. 

(4) For affected HPT stage 2 disks 

identified in Table 1 to paragraph (c) of this 

AD that are not included in paragraph (g)(2) 

of this AD, at the next piece part exposure 

or before the affected HPT stage 2 disk 

exceeds 12,000 CSN, whichever occurs first 

after the effective date of this AD, remove the 

affected HPT stage 2 disk from service and 

replace with a part eligible for installation. 

(h) Definitions 

For the purpose of this AD: 

(1) A ‘‘part eligible for installation’’ is any 

HPT stage 1 disk or HPT stage 2 disk that 

does not have a P/N and S/N identified in 

Table 1 to paragraph (c) of this AD. 

(2) A ‘‘piece part exposure’’ is when the 

affected part is removed from the engine and 

completely disassembled. 

(i) Grace Period for HPT Stage 1 Disk 

Replacement 

For affected HPT stage 1 disks having 

greater than 8,550 CSN on the effective date 

of this AD, the replacement required by 

paragraph (g)(3) of this AD may be deferred 

up to 50 flight cycles after the effective date 

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 local Flight Standards District Office, as 

appropriate. If sending information directly 

to the manager of AIR–520 Continued 

Operational Safety Branch, send it to the 

attention of the person identified in 

paragraph (k) of this AD and email to: 

AMOC@faa.gov. 

(2) Before using any approved AMOC, 

notify your appropriate principal inspector, 

or lacking a principal inspector, the manager 

of the local flight standards district office/ 

certificate holding district office. 

(k) Additional Information 

For more information about this AD, 

contact Alexei Marqueen, Aviation Safety 

Engineer, FAA, 2200 South 216th Street, Des 

Moines, WA 98198; phone: (781) 238–7178; 

email: alexei.t.marqueen@faa.gov. 

(l) Material Incorporated by Reference 

None. 

Issued on January 21, 2025. 

Suzanne Masterson, 

Deputy Director, Integrated Certificate 

Management Division, Aircraft Certification 

Service. 

[FR Doc. 2025–01728 Filed 1–29–25; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2025–0013; Project 

Identifier MCAI–2024–00375–A] 

RIN 2120–AA64 

Airworthiness Directives; Piaggio 

Aviation S.p.A. Airplanes 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Notice of proposed rulemaking 

(NPRM). 

SUMMARY: The FAA proposes to 

supersede Airworthiness Directive (AD) 

2023–25–03, which applies to certain 

Piaggio Aviation S.p.A. (Piaggio) Model 

P–180 airplanes. AD 2023–25–03 

requires a one-time detailed inspection 

of the horizontal stabilizer (HS) central 

box for corrosion; an assessment of the 

corrosion level; and depending on the 

determination, repetitive detailed 

inspections of the HS central box for 

corrosion and the internal composite 

structure for surface cracks, distortion, 

and damage; and repair or replacement 

of the HS assembly. Repair or 

replacement of the HS assembly is 

terminating action for the repetitive 

inspections. Since the FAA issued AD 

2023–25–03, it was determined that AD 

2023–25–03 imposed an unintended 

restriction that is not in the mandatory 

continuing airworthiness information 

(MCAI). This proposed AD would retain 

certain actions of AD–2023–25–03 and 

would remove the unintended 

restriction. The FAA is proposing this 

AD to address the unsafe condition on 

these products. 

DATES: The FAA must receive comments 

on this NPRM by March 17, 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–2025–0013; 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 MCAI, any 

comments received, and other 

information. The street address for 

Docket Operations is listed above. 

Material Incorporated by Reference: 

• For Piaggio material identified in 

this proposed AD, contact Piaggio 

Aviation S.p.A., P180 Customer 

Support, via Pionieri e Aviatori d’Italia, 

snc—16154 Genoa, Italy; phone: +39 

331 679 74 93; email: technicalsupport@

piaggioaerospace.it. 

• You may view this material at the 

FAA, Airworthiness Products Section, 

Operational Safety Branch, 901 Locust, 

Kansas City, MO 64106. For information 

on the availability of this material at the 

FAA, call (817) 222–5110. 

FOR FURTHER INFORMATION CONTACT: 

William McCully, Aviation Safety 

Engineer, FAA, 1600 Stewart Avenue, 

Suite 410, Westbury, NY 11590; phone: 

(404) 474–5548; email: 

william.mccully@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–2025–0013; Project Identifier 

MCAI–2024–00375–A’’ 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 the 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 


lotter on DSK11XQN23PROD with PROPOSALS1