[Federal Register Volume 89, Number 15 (Tuesday, January 23, 2024)]
[Rules and Regulations]
[Pages 4184-4187]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-01166]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2023-1647; Project Identifier AD-2023-00487-E;
Amendment 39-22650; AD 2023-26-07]
RIN 2120-AA64
Airworthiness Directives; General Electric Company Engines
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for
certain General Electric Company (GE) Model GE90-90B, GE90-94B, GE90-
110B1, and GE90-115B engines. This AD was prompted by a manufacturer
investigation that revealed certain high-pressure turbine (HPT) stage 1
disks, HPT stage 2 disks, forward HPT rotor seals, interstage HPT
seals, and stages 7-9 compressor rotor spools were manufactured from
powder metal material suspected to contain iron inclusion. This AD
requires replacement of affected HPT stage 1 disks, HPT stage 2 disks,
forward HPT rotor seals, interstage HPT seals, and stages 7-9
compressor rotor spools. The FAA is issuing this AD to address the
unsafe condition on these products.
DATES: This AD is effective February 27, 2024.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of February 27,
2024.
ADDRESSES:
AD Docket: You may examine the AD docket at regulations.gov under
Docket No. FAA-2023-1647; 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 General Electric Company, 1 Neumann Way, Cincinnati, OH 45215;
phone: (513) 552-3272; email: ge.com">aviation.fleetsupport@ge.com; website:
ge.com.
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. It is
also available at regulations.gov under Docket No. FAA-2023-1647.
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:
Background
The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 by adding an AD that would apply to certain GE Model GE90-
90B, GE90-94B, GE90-110B1, and GE90-115B engines. The NPRM published in
the Federal Register on September 5, 2023 (88 FR 60603). The NPRM was
prompted by the manufacturer's detection of iron inclusion in a turbine
disk manufactured from the same powder metal material used to
manufacture certain HPT stage 1 disks, HPT stage 2 disks, forward HPT
rotor seals, interstage HPT seals, and stages 7-9 compressor rotor
spools for GE90-90B, GE90-94B, GE90-110B1, and GE90-115B engines.
Further investigation by the manufacturer determined 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 subsequent
uncontained failure. The FAA was also informed that GE communicated
with affected operators having affected HPT stage 1 and stage 2 disks
identified in Table 1 to Paragraph (c) of this AD regarding the
corrective action for this unsafe condition. As a result, affected
operators are already aware of the corrective action and have already
performed the actions required by this AD. Therefore, the FAA has
determined that the compliance time to replace these affected HPT stage
1 and stage 2 disks before further flight is appropriate. In the NPRM,
the FAA proposed to require replacement of certain HPT stage 1 disks,
HPT stage 2 disks, forward HPT rotor seals, interstage HPT seals, and
stages 7-9 compressor rotor spools with parts eligible for
installation. The FAA is issuing this AD to address the unsafe
condition on these products.
Discussion of Final Airworthiness Directive
Comments
The FAA received comments from five commenters. Commenters included
[[Page 4185]]
The Boeing Company (Boeing), Federal Express (FedEx), GE, United
Airlines, and an individual commenter. Boeing, United Airlines, and the
individual commenter supported the NPRM without change. FedEx and GE
requested changes to the proposed AD. The following presents the
comments received on the NPRM and the FAA's response to each comment.
Request To Reference Additional Service Information
FedEx and GE requested that the FAA add the following service
information to the NPRM in a section designated as Other Related
Service Information: GE GE90-100 Service Bulletin (SB) 72-0904 R00,
dated May 25, 2022; GE GE90-100 SB 72-0911 R01, dated September 21,
2022; and GE GE90 SB 72-1223, dated January 25, 2023. FedEx and GE both
noted that Table 1 to Paragraph (c) of the proposed AD listed affected
components that were partially copied from those GE SBs, and not
including mention of those GE SBs could cause confusion for operators,
even though additional GE SBs would not be incorporated by reference.
The FAA agrees and for the ease of the reader, instead of including
these additional GE SBs in a section identified as Other Related
Service Information in the preamble, has added Note 1 to paragraph (c)
of this AD to include the three additional GE SBs identified by the
commenters and to clarify that the affected parts can also be found in
these additional GE SBs. These additional GE SBs will not be
incorporated by reference in this AD.
Request To Update Affected Part Number
GE requested that the FAA update Table 1 to Paragraph (c) of the
proposed AD by changing the part number (P/N) for an affected HPT stage
1 disk having serial number (S/N) GWN10NNW from ``1865M13G08'' to
``2445M04G11.'' GE noted that the HPT stage 1 disk with S/N GWN10NNW
was repaired and re-marked to P/N 2445M04G11.
The FAA agrees and has updated Table 1 to Paragraph (c) of this AD
as requested by GE.
Request To Clarify Language in Background Section
GE requested that the FAA add language to the Background section of
the NPRM to clarify that GE communicated with affected operators having
affected HPT stage 1 and stage 2 disks identified in Table 1 to
Paragraph (c) of the proposed AD regarding the proposed corrective
action for the identified unsafe condition. GE noted that the current
language in the NPRM does not specify that the affected disks are
identified in Table 1 to Paragraph (c) of the proposed AD, and
additional HPT stage 2 disks are identified in General Electric GE90-
100 Service Bulletin 72-0914, dated January 25, 2023, which could cause
a misinterpretation of the required actions on HPT stage 2 disks.
The FAA agrees and has revised the language in the Background
section of this final rule accordingly.
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 GE GE90-100 Service Bulletin (SB) 72-0914, dated
January 25, 2023 (GE GE90-100 SB 72-0914); which provides the affected
part and serial numbers of the HPT stage 2 disks, forward HPT rotor
seals, and stages 7-9 compressor rotor spools; and specifies
replacement instructions for the HPT stage 2 disks, forward HPT rotor
seals, and stages 7-9 compressor rotor spools. 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 the ADDRESSES section.
Interim Action
The FAA considers this AD to be an interim action. This unsafe
condition is still under investigation by the manufacturer and,
depending on the results of that investigation, the FAA may consider
further rulemaking action.
Costs of Compliance
The FAA estimates that this AD affects 9 engines installed on
airplanes of U.S. registry. The FAA estimates that 0 engines installed
on airplanes of U.S. registry require replacement of the interstage HPT
seal.
The FAA estimates the following costs to comply with this AD:
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 2 disk.............. 8 work-hours x $85 per $531,578 $532,258 $532,258
hour = $680.
Replace stages 7-9 compressor rotor 8 work-hours x $85.per 493,588 494,268 1,977,072
spool. hour = $680.
Replace forward HPT rotor seal........ 8 work-hours x $85 per 25,093 25,773 51,546
hour = $680.
Replace interstage HPT seal........... 8 work-hours x $85 per 108,256 108,936 0
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
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:
[[Page 4186]]
(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:
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:
2023-26-07 General Electric Company: Amendment 39-22650; Docket No.
FAA-2023-1647; Project Identifier AD-2023-00487-E.
(a) Effective Date
This airworthiness directive (AD) is effective February 27,
2024.
(b) Affected ADs
None.
(c) Applicability
This AD applies to General Electric Company (GE) Model GE90-90B
and GE90-94B engines with interstage HPT seals listed in Table 1 to
Paragraph (c) of this AD and GE90-110B1 and GE90-115B engines with
an installed high-pressure turbine (HPT) stage 1 disk, HPT stage 2
disk, forward HPT rotor seal, or stages 7-9 compressor rotor spool
part number (P/N) and serial number (S/N) identified in Table 1 to
Paragraph (c) of this AD, or identified in Paragraph 4. APPENDIX--A,
Tables 1, 2, or 3, of GE GE90-100 Service Bulletin (SB) 72-0914,
dated January 25, 2023 (GE90-100 SB 72-0914).
Table 1 to Paragraph (c)--Affected HPT Stage 1 and Stage 2 Disks, and
Interstage HPT Seals
[GRAPHIC] [TIFF OMITTED] TR23JA24.021
Note 1 to paragraph (c): Part numbers and serial numbers for
affected HPT stage 1 disks, HPT stage 2 disks, and interstage HPT
seals are also listed in GE GE90-100 Service Bulletin (SB) 72-0904
R00, dated May 25, 2022; GE GE90-100 SB 72-0911 R01, dated September
21, 2022; and GE GE90 SB 72-1223, dated January 25, 2023.
(d) Subject
Joint Aircraft System Component (JASC) Code 7230, Turbine Engine
Compressor Section; 7250, Turbine Section.
(e) Unsafe Condition
This AD was prompted by a manufacturer investigation that
revealed certain HPT stage 1 disks, HPT stage 2 disks, forward HPT
rotor seals, interstage HPT seals, and stages 7-9 compressor rotor
spools were manufactured from powder metal material suspected to
contain iron inclusion. The FAA is issuing this AD to prevent
premature fracture and subsequent uncontained failure. 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
At the applicable times specified in paragraphs (g)(1) through
(6) of this AD, remove each affected HPT stage 1 disk, HPT stage 2
disk, forward HPT rotor seal, interstage HPT seal, and stages 7-9
compressor rotor spool from service and replace with a part eligible
for installation.
(1) For HPT stage 1 disks, before further flight.
(2) For HPT stage 2 disks with a part number and serial number
identified in Paragraph 4. APPENDIX--A, Table 1 of GE90-100 SB 72-
0914, at the next piece part exposure or before exceeding 3,500
cycles since new (CSN), whichever occurs first.
(3) For HPT stage 2 disks with a part number and serial number
identified in Table 1 to paragraph (c) of this AD, before further
flight.
(4) For forward HPT rotor seals with a part number and serial
number identified in Paragraph 4. APPENDIX--A, Table 3 of GE90-100
SB 72-0914, at the next piece part exposure or before exceeding
14,200 CSN, whichever occurs first.
(5) For interstage HPT seals, at the next piece part exposure or
before exceeding 12,600 CSN, whichever occurs first.
[[Page 4187]]
(6) For stages 7-9 compressor rotor spools, at the next piece
part exposure or before exceeding the cyclic removal thresholds
identified in Paragraph 4. APPENDIX--A, Table 2 of GE90-100 SB 72-
0914, whichever occurs first.
(h) Definition
For the purpose of this AD, a ``part eligible for installation''
is any HPT stage 1 disk, HPT stage 2 disk, stages 7-9 compressor
rotor spool, forward HPT rotor seal, or interstage HPT seal with a
part number and serial number that is not identified in paragraph
(c) 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 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 (j) 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.
(j) 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].
(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) General Electric GE90-100 Service Bulletin 72-0914, dated
January 25, 2023.
(ii) [Reserved]
(3) For service information identified in this AD, contact
General Electric Company, 1 Neumann Way, Cincinnati, OH 45215;
phone: (513) 552-3272; email: ge.com">aviation.fleetsupport@ge.com; website:
ge.com.
(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 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, visit: www.archives.gov/federal-register/cfr/ibr-locations or
email: [email protected].
Issued on January 2, 2024.
Caitlin Locke,
Director, Compliance & Airworthiness Division, Aircraft Certification
Service.
[FR Doc. 2024-01166 Filed 1-22-24; 8:45 am]
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