Airworthiness Directives; General Electric Company Engines
| Court | Federal Aviation Administration |
| Citation | 88 FR 60603 |
| Published date | 05 September 2023 |
| Record Number | 2023-18858 |
Federal Register, Volume 88 Issue 170 (Tuesday, September 5, 2023)
[Federal Register Volume 88, Number 170 (Tuesday, September 5, 2023)]
[Proposed Rules]
[Pages 60603-60605]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-18858]
=======================================================================
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2023-1647; Project Identifier AD-2023-00487-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 GE90-90B, GE90-94B,
GE90-110B1, and GE90-115B engines. This proposed 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 proposed AD would require 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 proposing
this AD to address the unsafe condition on these products.
DATES: The FAA must receive comments on this proposed AD by October 20,
2023.
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 by
searching for and locating 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 NPRM, any comments
received, and other information. The street address for Docket
Operations is listed above.
Material Incorporated by Reference:
For service information incorporated by reference in this
NPRM, 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.
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 ADDRESSES. Include ``Docket No. FAA-2023-1647; Project Identifier
AD-2023-00487-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
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 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 has been informed that GE has communicated
with affected operators with affected HPT stage 1 and stage 2 disks
regarding the proposed corrective action for this unsafe condition. As
a result, affected operators are already aware of the proposed
corrective action and have already performed the actions proposed in
this AD. Therefore, the FAA has determined that the compliance time to
replace the affected HPT stage 1 and stage 2 disks before further
flight is
[[Page 60604]]
appropriate. This condition, if not addressed, could result in
uncontained debris release, damage to the engine, and damage to the
airplane. The FAA is proposing this AD to address the unsafe condition
on these products.
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 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 ADDRESSES.
Proposed AD Requirements in This NPRM
This proposed AD would 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.
Differences Between This Proposed AD and the Service Information
GE GE90-100 SB 72-0914, uses the term ``HPT rotor stage 2 disk,''
while this proposed AD uses the term ``HPT stage 2 disk.''
GE GE90-100 SB 72-0914, Effectivity, identifies GE Model GE-90-
110B1 and GE-90-115B engines. The GE Model GE90-90B and GE90-94B
engines are also affected by the unsafe condition, however, the FAA is
not incorporating service information that is specific to GE Model
GE90-90B and GE90-94B engines.
Interim Action
The FAA considers that this proposed AD would 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, if adopted as proposed, would
affect 9 engines installed on airplanes of U.S. registry. The FAA
estimates that 0 engines installed on airplanes of U.S. registry would
require replacement of the interstage HPT seal. The FAA estimates the
following costs to comply with this proposed AD:
Estimated Costs
----------------------------------------------------------------------------------------------------------------
Cost per Cost on U.S.
Action Labor cost Parts cost product operators
----------------------------------------------------------------------------------------------------------------
Replace HPT stage 1 disk.............. 8 work-hours x $85 per $1,116,300 $1,116,980 $2,233,960
hour = $680.
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.
----------------------------------------------------------------------------------------------------------------
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-2023-1647; Project
Identifier AD-2023-00487-E.
(a) Comments Due Date
The FAA must receive comments on this airworthiness directive
(AD) by October 20, 2023.
(b) Affected ADs
None.
(c) Applicability
This AD applies to General Electric Company (GE) Model GE90-90B
and GE90-94B with interstage HPT seals listed in Table 1 to
Paragraph (c) 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
[[Page 60605]]
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
----------------------------------------------------------------------------------------------------------------
Part name P/N S/N
----------------------------------------------------------------------------------------------------------------
HPT stage 1 disk........................ 1865M13G08...................... GWN11657
GWN117GN
GWN10NNW
GWN10PGW
GWN10T0A
GWN10T0C
GWN10THW
GWN10TJ0
----------------------------------------------------------------------------------------------------------------
HPT stage 2 disk........................ 1865M14P04...................... TMT4RN06
TMT4RN26
----------------------------------------------------------------------------------------------------------------
Interstage HPT seal..................... 2453M60P01...................... NCU61528
NCU61686
NCU56200
NCU61527
NCU61687
----------------------------------------------------------------------------------------------------------------
(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 P/N and S/N 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 P/N and S/N identified in Table
1 to paragraph (c) of this AD, before further flight.
(4) For forward HPT rotor seals with a P/N and S/N 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.
(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
P/N and S/N 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) 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: [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 incorporated by reference 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, email: [email protected], or go to: www.archives.gov/federal-register/cfr/ibr-locations.html.
Issued on August 11, 2023.
Ross Landes,
Deputy Director for Regulatory Operations, Compliance & Airworthiness
Division, Aircraft Certification Service.
[FR Doc. 2023-18858 Filed 9-1-23; 8:45 am]
BILLING CODE 4910-13-P
