Proposed Rule2024-05995
Airworthiness Directives; General Electric Company Engines
Primary source
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Published
March 25, 2024
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA proposes to adopt a new airworthiness directive (AD) for certain General Electric Company (GE) Model GEnx-1B64/P1, GEnx- 1B64/P2, GEnx-1B67, GEnx-1B67/P1, GEnx-1B67/P2, GEnx-1B70, GEnx-1B70/ 75/P1, GEnx-1B70/75/P2, GEnx-1B70/P1, GEnx-1B70/P2, GEnx-1B70C/P1, GEnx-1B70C/P2, GEnx-1B74/75/P1, GEnx-1B74/75/P2, GEnx-1B76/P2, GEnx- 1B76A/P2, GEnx-2B67, GEnx-2B67B, and GEnx-2B67/P engines. This proposed AD was prompted by a manufacturer evaluation that determined a lower life limit is necessary for certain stages 6-10 compressor rotor spools (stages 6-10 spools) than allowed by the engine shop manual (ESM). This proposed AD would require a one-time inspection of the stages 6-10 spools for previously accomplished blend repairs, a one-time inspection of the blend repairs on the stages 6-10 spools for compliance with the updated allowable limits, and replacement if necessary. The FAA is proposing this AD to address the unsafe condition on these products.
Full Text
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<title>Federal Register, Volume 89 Issue 58 (Monday, March 25, 2024)</title>
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[Federal Register Volume 89, Number 58 (Monday, March 25, 2024)]
[Proposed Rules]
[Pages 20553-20555]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2024-05995]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2024-0755; Project Identifier AD-2023-00521-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 GEnx-1B64/P1, GEnx-
1B64/P2, GEnx-1B67, GEnx-1B67/P1, GEnx-1B67/P2, GEnx-1B70, GEnx-1B70/
75/P1, GEnx-1B70/75/P2, GEnx-1B70/P1, GEnx-1B70/P2, GEnx-1B70C/P1,
GEnx-1B70C/P2, GEnx-1B74/75/P1, GEnx-1B74/75/P2, GEnx-1B76/P2, GEnx-
1B76A/P2, GEnx-2B67, GEnx-2B67B, and GEnx-2B67/P engines. This proposed
AD was prompted by a manufacturer evaluation that determined a lower
life limit is necessary for certain stages 6-10 compressor rotor spools
(stages 6-10 spools) than allowed by the engine shop manual (ESM). This
proposed AD would require a one-time inspection of the stages 6-10
spools for previously accomplished blend repairs, a one-time inspection
of the blend repairs on the stages 6-10 spools for compliance with the
updated allowable limits, and replacement if necessary. 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 May 9,
2024.
ADDRESSES: You may send comments, using the procedures found in 14 CFR
11.43 and 11.45, by any of the following methods:
<bullet> Federal eRulemaking Portal: Go to <a href="http://regulations.gov">regulations.gov</a>. Follow
the instructions for submitting comments.
<bullet> Fax: (202) 493-2251.
<bullet> 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.
<bullet> 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 <a href="http://regulations.gov">regulations.gov</a> under
Docket No. FAA-2024-0755; 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:
<bullet> For service information identified in this NPRM, contact
GE, 1 Neumann Way, Cincinnati, OH 45215; phone: (513) 552-3272; email:
<a href="/cdn-cgi/l/email-protection#3455425d55405d5b5a1a5258515140474144445b4640740855145c46515209" http: ge.com">ge.com</a>">aviation.fleetsupport@<a href="http://ge.com">ge.com</a></a>; website: <a href="http://ge.com">ge.com</a>.
<bullet> You may view this service information at the FAA,
Airworthiness Products Section, Operational Safety Branch, 1200
District Avenue, Burlington, MA 01803. For information on the
availability of this material at the FAA, call (817) 222-5110.
FOR FURTHER INFORMATION CONTACT: Alexei Marqueen, Aviation Safety
Engineer, FAA, 2200 South 216th Street, Des Moines, WA 98198; phone:
(781) 238-7178; email: <a href="/cdn-cgi/l/email-protection#11707d746974783f653f7c7063606474747f517770703f767e67"><span class="__cf_email__" data-cfemail="741518110c111d5a005a191506050111111a341215155a131b02">[email protected]</span></a>.
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-2024-0755; Project Identifier
AD-2023-00521-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 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
<a href="http://regulations.gov">regulations.gov</a>, 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 of a manufacturer evaluation, which consisted
of a heat transfer analysis, that revealed significant changes in
thermal gradients in certain areas of the high-pressure compressor
rotor (HPCR) assembly on GE Model GEnx-1B64/P1, GEnx-1B64/P2, GEnx-
1B67, GEnx-1B67/P1, GEnx-1B67/P2, GEnx-1B70, GEnx-1B70/75/P1, GEnx-
1B70/75/P2, GEnx-1B70/P1, GEnx-1B70/P2, GEnx-1B70C/P1, GEnx-1B70C/P2,
GEnx-1B74/75/P1, GEnx-1B74/75/P2, GEnx-1B76/P2, GEnx-1B76A/P2, GEnx-
2B67, GEnx-2B67B, and GEnx-2B67/P engines. The results of the heat
transfer analysis were used to determine that a lower life limit is
required for certain areas of the HPCR. Consequently, the manufacturer
re-checked the serviceable and repairable limits of the stages 6-10
spools to determine if they still maintained the threshold limit for
serviceability, where it was discovered that two repair procedures
listed in the ESM exceeded the updated repair limits at certain
locations of the HPCR assembly.
Due to the findings of the previous evaluations, the manufacturer
performed an updated analysis and determined that a new threshold for
the repairable limits for blend-repaired stages 6-10 spools is
necessary. The manufacturer also determined that certain areas of
previous blend-repaired stages 6-10 spools may have a lower life limit
than the ultimate life limit of the HPCR disks.
This condition, if not addressed, could result in fracture and
potential uncontained failure of the stages 6-10 spools, with
consequent uncontained
[[Page 20554]]
debris release, damage to the engine, and damage to the aircraft.
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 GE GEnx-1B Service Bulletin 72-0525, R00, dated
October 4, 2023 (GEnx-1B SB 72-0525, R00), and GEnx-2B Service Bulletin
72-0460, R00, dated October 4, 2023 (GEnx-2B SB 72-0460, R00). This
service information identifies the part numbers and serial numbers of
affected stages 6-10 spools; and specifies instructions for a one-time
inspection of the stages 6-10 spools for previously accomplished blend
repairs, a one-time inspection of the blend repairs on the stages 6-10
spools for compliance with the updated allowable limits, and
replacement if necessary. These documents are distinct since they apply
to different engine models.
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 section.
Proposed AD Requirements in This NPRM
This NPRM would require accomplishing a one-time inspection of the
stages 6-10 spools for previously accomplished blend repairs, a one-
time inspection of the blend repairs on the stages 6-10 spools for
compliance with the updated allowable limits, and replacement, if
necessary, within compliance times specified in GE GEnx-1B SB 72-0525,
R00 or GEnx-2B SB 72-0460, R00. Depending on the part numbers and
serial numbers of the affected stages 6-10 spools, this NPRM proposes
to require these actions to be accomplished at the next piece-part
exposure after the effective date of this proposed AD, or before the
affected stages 6-10 spool reaches the cyclic removal threshold of up
to 11,894 cycles since new.
Costs of Compliance
The FAA estimates that this AD, if adopted as proposed, would
affect 6 engines installed on airplanes of U.S. registry.
The FAA estimates the following costs to comply with this proposed
AD:
Estimated Costs
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Cost per Cost on U.S.
Action Labor cost Parts cost product operators
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Inspect stages 6-10 spools............ 8 work-hours x $85 per $0 $680 $4,080
hour = $680.
Inspect previous blend repairs........ 1 work-hours x $85 per 0 85 510
hour = $85.
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The FAA estimates the following costs to do any necessary
replacements that would be required based on the results of the
proposed inspections. The agency has no way of determining the number
of engines that might need this replacement:
On-Condition Costs
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Cost per
Action Labor cost Parts cost product
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Replace stages 6-10 spool..................... 8 work-hours x $85 per hour = $1,307,600 $1,308,280
$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-2024-0755; Project
Identifier AD-2023-00521-E.
[[Page 20555]]
(a) Comments Due Date
The FAA must receive comments on this airworthiness directive
(AD) by May 9, 2024.
(b) Affected ADs
None.
(c) Applicability
This AD applies to General Electric Company (GE) Model GEnx-
1B64/P1, GEnx-1B64/P2, GEnx-1B67, GEnx-1B67/P1, GEnx-1B67/P2, GEnx-
1B70, GEnx-1B70/75/P1, GEnx-1B70/75/P2, GEnx-1B70/P1, GEnx-1B70/P2,
GEnx-1B70C/P1, GEnx-1B70C/P2, GEnx-1B74/75/P1, GEnx-1B74/75/P2,
GEnx-1B76/P2, GEnx-1B76A/P2, GEnx-2B67, GEnx-2B67B, and GEnx-2B67/P
engines with an installed:
(1) Stages 6-10 compressor rotor spool (stages 6-10 spool)
having a part number (P/N) and serial number (S/N) listed in
paragraph 4, Appendix--A, Table 1 of GE GEnx-1B Service Bulletin 72-
0525, R00, dated October 4, 2023 (GEnx-1B SB 72-0525, R00); or
(2) Stages 6-10 spool having a P/N and S/N listed in paragraph
4, Appendix--A, Table 1 of GE GEnx-2B Service Bulletin 72-0460, R00,
dated October 4, 2023 (GEnx-2B SB 72-0460, R00).
(d) Subject
Joint Aircraft System Component (JASC) Code 7230, Turbine Engine
Compressor Section.
(e) Unsafe Condition
This AD was prompted by a manufacturer evaluation which
determined that a lower life limit is necessary for certain stages
6-10 spools than that allowed in the engine shop manual. The FAA is
issuing this AD to prevent fracture and potential uncontained
failure of the stages 6-10 spools. The unsafe condition, if not
addressed, could result in uncontained debris release, damage to the
engine, and damage to the aircraft.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Required Actions
At the next piece-part exposure after the effective date of this
AD or before the affected stages 6-10 spool reaches the cyclic
removal threshold specified in paragraph 4., Appendix--A, Table 1 of
GEnx-1B 72-0525, R00 or GEnx-2B SB 72-0460, R00, as applicable, do
the following actions:
(1) Inspect the stages 6-10 spool for previously accomplished
blend repairs in accordance with the Accomplishment Instructions,
paragraph 3.B.(1) of GEnx-1B SB 72-0525, R00 or GEnx-2B SB 72-0460,
R00, as applicable.
(2) If during any inspection required by paragraph (g)(1) of
this AD, any stages 6-10 spool is found to have a previously
accomplished blend repair, before further flight, inspect the blend
repair for compliance with the allowable limits in accordance with
the Accomplishment Instructions, paragraph 3.B.(2) of GEnx-1B SB 72-
0525, R00 or GEnx-2B SB 72-0460, R00, as applicable.
(3) If during any inspection required by paragraph (g)(2) of
this AD, any stages 6-10 spool is found to have a previously
accomplished blend repair that is not within the allowable limits,
before further flight, remove the stages 6-10 spool from service and
replace with a part eligible for installation in accordance with the
Accomplishment Instructions, paragraph 3.B.(2)(a)1 or 3.B.(2)(b)1 of
GEnx-1B SB 72-0525, R00 or GEnx-2B SB 72-0460, R00, as applicable.
(h) Definition
(1) For the purpose of this AD, a ``piece-part exposure'' is
when the stages 6-10 spool is disassembled from the high-pressure
compressor rotor assembly.
(2) For the purpose of this AD, a ``part eligible for
installation'' is a stages 6-10 spool that does not have a P/N and
S/N identified in paragraph 4, Appendix--A, Table 1 of GEnx-1B 72-
0525, R00 or GEnx-2B 72-0460, R00.
(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 local
Flight Standards District Office, as appropriate. If sending
information directly to the manager of the AIR-520 Continued
Operational Safety Branch, send it to the attention of the person
identified in paragraph (j) of this AD and email to: <a href="/cdn-cgi/l/email-protection#175659523a56533a565a58545771767639707861"><span class="__cf_email__" data-cfemail="1b5a555e365a5f365a5654585b7d7a7a357c746d">[email protected]</span></a>.
(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.
(j) Related 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: <a href="/cdn-cgi/l/email-protection#c8a9a4adb0ada1e6bce6a5a9bab9bdadada688aea9a9e6afa7be"><span class="__cf_email__" data-cfemail="f59499908d909cdb81db989487848090909bb5939494db929a83">[email protected]</span></a>.
(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) General Electric Company (GE) GEnx-1B Service Bulletin 72-
0525, R00, dated October 4, 2023.
(ii) GE GEnx-2B Service Bulletin 72-0460, R00, dated October 4,
2023.
(4) You may view this service information at FAA, Airworthiness
Products Section, Operational Safety Branch, 1200 District Avenue,
Burlington, MA 01803. For information on the availability of this
material at the FAA, call (817) 222-5110.
(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 <a href="http://www.archives.gov/federal-register/cfr/ibr-locations">www.archives.gov/federal-register/cfr/ibr-locations</a> or email <a href="/cdn-cgi/l/email-protection#b7d1c599ded9c4c7d2d4c3ded8d9f7d9d6c5d699d0d8c1"><span class="__cf_email__" data-cfemail="7016025e191e0300151304191f1e301e1102115e171f06">[email protected]</span></a>.
Issued on March 15, 2024.
Victor Wicklund,
Deputy Director, Compliance & Airworthiness Division, Aircraft
Certification Service.
[FR Doc. 2024-05995 Filed 3-22-24; 8:45 am]
BILLING CODE 4910-13-P
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