Proposed Rule2022-11346
Airworthiness Directives; General Electric Company Turbofan Engines
Primary source
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Published
May 27, 2022
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA proposes to adopt a new airworthiness directive (AD) for all General Electric Company (GE) GE90-110B1 and GE90-115B model turbofan engines and certain GE90-76B, GE90-85B, GE90-90B, and GE90-94B model turbofan engines. This proposed AD was prompted by the detection of melt-related freckles in the forgings and billets, which may reduce the life of certain rotating compressor discharge pressure (CDP) high- pressure turbine (HPT) seals (rotating CDP seals), interstage HPT rotor seals, and HPT rotor stage 2 disks. This proposed AD would require revising the airworthiness limitations section (ALS) of the applicable GE90-100 Engine Manual (EM) and the operator's existing approved maintenance program or inspection program, as applicable, to incorporate reduced life limits for these parts. This proposed AD would also require the removal and replacement of certain interstage HPT rotor seals, identified by serial number (S/N), installed on GE90-76B, GE90-85B, GE90-90B, and GE90-94B model turbofan engines. The FAA is proposing this AD to address the unsafe condition on these products.
Full Text
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<title>Federal Register, Volume 87 Issue 103 (Friday, May 27, 2022)</title>
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[Federal Register Volume 87, Number 103 (Friday, May 27, 2022)]
[Proposed Rules]
[Pages 32098-32103]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2022-11346]
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Proposed Rules
Federal Register
________________________________________________________________________
This section of the FEDERAL REGISTER contains notices to the public of
the proposed issuance of rules and regulations. The purpose of these
notices is to give interested persons an opportunity to participate in
the rule making prior to the adoption of the final rules.
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Federal Register / Vol. 87, No. 103 / Friday, May 27, 2022 / Proposed
Rules
[[Page 32098]]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2022-0516; Project Identifier AD-2022-00262-E]
RIN 2120-AA64
Airworthiness Directives; General Electric Company Turbofan
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 all General Electric Company (GE) GE90-110B1 and GE90-115B model
turbofan engines and certain GE90-76B, GE90-85B, GE90-90B, and GE90-94B
model turbofan engines. This proposed AD was prompted by the detection
of melt-related freckles in the forgings and billets, which may reduce
the life of certain rotating compressor discharge pressure (CDP) high-
pressure turbine (HPT) seals (rotating CDP seals), interstage HPT rotor
seals, and HPT rotor stage 2 disks. This proposed AD would require
revising the airworthiness limitations section (ALS) of the applicable
GE90-100 Engine Manual (EM) and the operator's existing approved
maintenance program or inspection program, as applicable, to
incorporate reduced life limits for these parts. This proposed AD would
also require the removal and replacement of certain interstage HPT
rotor seals, identified by serial number (S/N), installed on GE90-76B,
GE90-85B, GE90-90B, and GE90-94B model turbofan engines. 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 July 11,
2022.
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="https://www.regulations.gov">https://www.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.
For service information identified in this NPRM, contact General
Electric Company, 1 Neumann Way, Cincinnati, OH 45215; phone: (513)
552-3272; email: <a href="/cdn-cgi/l/email-protection#ceafb8a7afbaa7a1a0e0a8a2ababbabdbbbebea1bcba8ea9abe0ada1a3"><span class="__cf_email__" data-cfemail="3f5e49565e4b5650511159535a5a4b4c4a4f4f504d4b7f585a115c5052">[email protected]</span></a>; website: <a href="https://www.ge.com">https://www.ge.com</a>. 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.
Examining the AD Docket
You may examine the AD docket at <a href="https://www.regulations.gov">https://www.regulations.gov</a> by
searching for and locating Docket No. FAA-2022-0516; 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, ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803;
phone: (781) 238-7178; email: <a href="/cdn-cgi/l/email-protection#c485a8a1bca1adea90ea89a5b6b5b1a1a1aa84a2a5a5eaa3abb2"><span class="__cf_email__" data-cfemail="6a2b060f120f03443e44270b181b1f0f0f042a0c0b0b440d051c">[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-2022-0516; Project Identifier
AD-2022-00262-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="https://www.regulations.gov">https://www.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, ECO Branch, FAA, 1200
District Avenue, Burlington, MA 01803. 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 engine manufacturer of the detection of
melt-related freckles in the forgings and billets, which may reduce the
life of certain rotating CDP seals, interstage HPT rotor seals, and HPT
rotor stage 2 disks on GE90-110B1 and GE90-115B model turbofan engines
and may reduce the life of certain interstage HPT rotor seals on GE90-
76B, GE90-85B, GE90-90B, and GE90-94B model turbofan engines. The
manufacturer's investigation determined that, as a result of such
freckles forming in the forgings and billets, certain rotating CDP
seals, interstage HPT rotor seals, and HPT rotor stage 2 disks (life-
limited parts (LLPs)) may have undetected subsurface anomalies that
developed during the manufacturing process,
[[Page 32099]]
resulting in reduced material properties and a lower fatigue life
capability. Reduced material properties may cause premature LLP
fracture, which could result in uncontained debris release. As a result
of its investigation, the manufacturer determined the need to reduce
the life limits of certain LLPs. To reflect these reduced life limits,
the manufacturer revised the ALS of the affected GE90-100 EMs.
Additionally, the manufacturer published service information that
specifies procedures for the removal and replacement of certain
interstage HPT rotor seals installed on GE90-76B, GE90-85B, GE90-90B,
and GE90-94B model turbofan engines. This condition, 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.
Related Service Information
The FAA reviewed GE GE90-100 Service Bulletin (SB) 72-0851 R00,
dated August 17, 2021. This SB provides the reduced life limits for
certain LLPs. The FAA also reviewed GE GE90 SB 72-1211 R00, dated March
9, 2022. This SB describes procedures for removing and replacing
certain interstage HPT rotor seals.
Proposed AD Requirements in This NPRM
This proposed AD would require revising the ALS of the applicable
GE90-100 EM and the operator's existing approved maintenance program or
inspection program, as applicable, to incorporate reduced life limits
for certain LLPs. This proposed AD would also require the removal and
replacement of certain interstage HPT rotor seals.
Differences Between This Proposed AD and the Service Information
GE90-100 SB 72-0851 R00, dated August 17, 2021, uses the term ``HPT
rotor interstage seals,'' while this proposed AD uses the term
``interstage HPT rotor seals.''
Costs of Compliance
The FAA estimates that this AD, if adopted as proposed, would
affect 248 engines installed on airplanes of U.S. registry. The FAA
estimates that zero engines installed on airplanes of U.S. registry
would require replacement of the interstage HPT rotor 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
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Revise ALS of EM and the operator's 1 work-hour x $85 per $0 $85 $21,080
existing approved maintenance program hour = $85.
or inspection program.
Replace interstage HPT rotor seal..... 1,500 work-hours x $85 286,331 413,831 0
per hour = $127,500.
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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-2022-0516; Project
Identifier AD-2022-00262-E.
(a) Comments Due Date
The FAA must receive comments on this airworthiness directive
(AD) by July 11, 2022.
(b) Affected ADs
None.
(c) Applicability
This AD applies to:
(1) General Electric Company (GE) GE90-110B1 and GE90-115B model
turbofan engines; and
(2) GE GE90-76B, GE90-85B, GE90-90B, and GE90-94B model turbofan
engines with an installed interstage high-pressure turbine (HPT)
rotor seal with part number (P/N) 2629M47P01 and serial number (S/N)
NCU5430D.
(d) Subject
Joint Aircraft System Component (JASC) Code 7230, Turbine Engine
Compressor Section, and JASC Code 7250, Turbine Section.
(e) Unsafe Condition
This AD was prompted by the detection of melt-related freckles
in the forgings and
[[Page 32100]]
billets, which may reduce the life of certain rotating compressor
discharge pressure (CDP) HPT seals (rotating CDP seal), interstage
HPT rotor seals, and HPT rotor stage 2 disks. The FAA is issuing
this AD to prevent failure of the rotating CDP seal, interstage HPT
rotor seal, and HPT rotor stage 2 disk. 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) For affected GE90-110B1 and GE90-115B model turbofan
engines, within 90 days after the effective date of this AD, revise
the airworthiness limitations section (ALS) of the existing GE90-100
Engine Manual (EM) and the operator's existing approved maintenance
program or inspection program, as applicable, by inserting the
following information:
(i) For rotating CDP seal P/N 2479M03P01, insert the information
in Table 1 to paragraph (g)(1)(i) of this AD.
BILLING CODE 4910-13-P
[GRAPHIC] [TIFF OMITTED] TP27MY22.000
(ii) For interstage HPT rotor seal P/N 2505M72P01, insert the
information in Table 2 to paragraph (g)(1)(ii) of this AD.
[[Page 32101]]
[GRAPHIC] [TIFF OMITTED] TP27MY22.001
(iii) For HPT rotor stage 2 disk P/N 2505M73P03, insert the
information in Table 3 to paragraph (g)(1)(iii) of this AD.
[[Page 32102]]
[GRAPHIC] [TIFF OMITTED] TP27MY22.002
(2) For affected GE90-76B, GE90-85B, GE90-90B, and GE90-94B
model turbofan engines, before the interstage HPT rotor seal, P/N
2629M47P01 and S/N NCU5430D, accumulates 7,400 cycles since new,
remove the affected interstage HPT rotor seal from service and
replace with a part eligible for installation.
(h) Definitions
For the purpose of this AD, a ``part eligible for installation''
is any interstage HPT rotor seal that does not have P/N 2629M47P01
and S/N NCU5430D.
(i) Alternative Methods of Compliance (AMOCs)
(1) The Manager, ECO 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
certification office, send it to the attention of the person
identified in paragraph (j)(1) of this AD and email to: <a href="/cdn-cgi/l/email-protection#13525d563e52573e525e5c50537572723d747c65"><span class="__cf_email__" data-cfemail="d0919e95fd9194fd919d9f9390b6b1b1feb7bfa6">[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
(1) For more information about this AD, contact Alexei Marqueen,
Aviation Safety Engineer, ECO Branch, FAA, 1200 District Avenue,
Burlington, MA 01803; phone: (781) 238-7178; email:
<a href="/cdn-cgi/l/email-protection#beffd2dbc6dbd790ea90f3dfcccfcbdbdbd0fed8dfdf90d9d1c8"><span class="__cf_email__" data-cfemail="da9bb6bfa2bfb3f48ef497bba8abafbfbfb49abcbbbbf4bdb5ac">[email protected]</span></a>.
[[Page 32103]]
(2) For service information identified in this AD, contact
General Electric Company, 1 Neumann Way, Cincinnati, OH 45215;
phone: (513) 552-3272; email: <a href="/cdn-cgi/l/email-protection#600116090114090f0e4e060c050514131510100f12142007054e030f0d"><span class="__cf_email__" data-cfemail="600116090114090f0e4e060c050514131510100f12142007054e030f0d">[email protected]</span></a>; website:
<a href="https://www.ge.com">https://www.ge.com</a>. You may view this referenced 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.
Issued on May 5, 2022.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification
Service.
[FR Doc. 2022-11346 Filed 5-26-22; 8:45 am]
BILLING CODE 4910-13-C
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