[Federal Register Volume 90, Number 19 (Thursday, January 30, 2025)]
[Proposed Rules]
[Pages 8505-8507]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2025-01728]
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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).
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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 high-pressure
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: [email protected].
SUPPLEMENTARY INFORMATION:
Comments Invited
The FAA invites you to send any written relevant data, views, or
arguments about this proposal. Send your comments to an address listed
under 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:
[[Page 8506]]
Estimated Costs
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Cost per Cost on U.S.
Action Labor cost Parts cost product operators
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Replace HPT stage 1 disk.......... 8 work-hours x $85 $1,228,800 (prorated) $1,229,480 $1,229,480
per hour = $680.
Replace HPT stage 2 disk.......... 8 work-hours x $85 $201,600 (prorated).. 202,280 202,280
per hour = $680.
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Authority for This Rulemaking
Title 49 of the United States Code specifies the FAA's authority to
issue rules on aviation safety. Subtitle I, section 106, describes the
authority of the FAA Administrator. Subtitle VII: Aviation Programs,
describes in more detail the scope of the Agency's authority.
The FAA is issuing this rulemaking under the authority described in
Subtitle VII, Part A, Subpart III, Section 44701: General requirements.
Under that section, Congress charges the FAA with promoting safe flight
of civil aircraft in air commerce by prescribing regulations for
practices, methods, and procedures the Administrator finds necessary
for safety in air commerce. This regulation is within the scope of that
authority because it addresses an unsafe condition that is likely to
exist or develop on products identified in this rulemaking action.
Regulatory Findings
The FAA determined that this proposed AD would not have federalism
implications under Executive Order 13132. This proposed AD would not
have a substantial direct effect on the States, on the relationship
between the national government and the States, or on the distribution
of power and responsibilities among the various levels of government.
For the reasons discussed above, I certify this proposed
regulation:
(1) Is not a ``significant regulatory action'' under Executive
Order 12866,
(2) Would not affect intrastate aviation in Alaska, and
(3) Would not have a significant economic impact, positive or
negative, on a substantial number of small entities under the criteria
of the Regulatory Flexibility Act.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.
The Proposed Amendment
Accordingly, under the authority delegated to me by the
Administrator, the FAA proposes to amend 14 CFR part 39 as follows:
PART 39--AIRWORTHINESS DIRECTIVES
0
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
0
2. The FAA amends Sec. 39.13 by adding the following new airworthiness
directive:
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
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Part name P/N S/N
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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.
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(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.
[[Page 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: [email protected].
(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: [email protected].
(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]
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