Airworthiness Directives; General Electric Company Turbofan Engines
| Published date | 13 August 2020 |
| Citation | 85 FR 49322 |
| Record Number | 2020-17594 |
| Section | Proposed rules |
| Court | Federal Aviation Administration |
Federal Register, Volume 85 Issue 157 (Thursday, August 13, 2020)
[Federal Register Volume 85, Number 157 (Thursday, August 13, 2020)]
[Proposed Rules]
[Pages 49322-49324]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-17594]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2020-0733; Project Identifier AD-2020-00990-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 certain General Electric Company (GE) GE90-110B1 and GE90-115B
model turbofan engines. This proposed AD was prompted by the detection
of melt-related freckles in the billet, which may reduce the life
limits of certain high-pressure turbine (HPT) rotor stage 2 disks and
certain rotating compressor discharge pressure (CDP) HPT seals. This
proposed AD would require replacement of the affected HPT rotor stage 2
disks and rotating CDP HPT seals. 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 September
14, 2020.
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 https://www.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.
For service information identified in this NPRM, contact General
Electric Company, 1 Neumann Way, Cincinnati, OH 45215; phone: (513)
552-3272; email: [email protected]; website: www.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 781-238-7759.
Examining the AD Docket
You may examine the AD docket on the internet at https://www.regulations.gov by searching for and locating Docket No. FAA-2020-
0733; 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: Mehdi Lamnyi, Aerospace Engineer, ECO
Branch, FAA, 1200 District Avenue, Burlington, MA 01803; phone: (781)
238-7743; fax: (781) 238-7999; 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-2020-0733;
Project Identifier AD-2020-00990-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 NPRM because of those comments.
The FAA has been informed that GE has communicated with affected
operators regarding the proposed corrective action for this unsafe
condition. As a result, affected operators are already aware of the
proposed corrective action and, in some cases, have already performed
the actions proposed in this AD. Therefore, the FAA has determined that
a 30-day comment period is appropriate given the proposed short cyclic
compliance period to correct the unsafe condition on the affected GE90
model turbofan engines.
Except for Confidential Business Information 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
https://www.regulations.gov, including any
[[Page 49323]]
personal information you provide. The FAA will also post a report
summarizing each substantive verbal contact received about this
proposal.
Confidential Business Information
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 Mehdi Lamnyi, Aerospace 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 of the detection of melt-related freckles in
the billet during the forging inspection of HPT disks, which may reduce
the life limits of certain HPT rotor stage 2 disks and certain rotating
CDP HPT seals. The inspection process in place at the time of
production did not identify these freckles. The manufacturer determined
the need to reduce the life limits of the affected HPT rotor stage 2
disks and rotating CDP HPT seals. This AD requires removal of these
affected parts before reaching their new life limits. This condition,
if not addressed, could result in uncontained release of both the HPT
rotor stage 2 disk and the rotating CDP HPT seal, damage to the engine,
and damage to the aircraft.
FAA's Determination
The FAA is proposing this AD because the agency has determined the
unsafe condition described previously is likely to exist or develop in
other products of the same type design.
Related Service Information
The FAA reviewed GE Service Bulletin (SB) GE90-100 S/B 72-0845,
Revision 01, dated July 17, 2020. The SB describes procedures for
removal of the HPT rotor stage 2 disk and the rotating CDP HPT seal
from service. 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.
Proposed AD Requirements
This proposed AD would require replacement of certain HPT rotor
stage 2 disks and certain rotating CDP HPT seals.
Interim Action
The FAA considers this proposed AD an interim action. This issue 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, as proposed, would affect 1 engine
installed on an airplane 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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Remove and replace the HPT rotor stage 1,500 work-hours x $85 $565,600 $693,100 $693,100
2 disk. per hour = $127,500.
Remove and replace the rotating CDP 600 work-hours x $85 per 209,900 260,900 0
HPT seal. hour = $51,000.
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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) 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 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.
[[Page 49324]]
Sec. 39.13 [Amended]
0
2. The FAA amends Sec. 39.13 by adding the following new airworthiness
directive (AD):
General Electric Company: Docket No. FAA-2020-0733; Project
Identifier AD-2020-00990-E.
(a) Comments Due Date
The FAA must receive comments by September 14, 2020.
(b) Affected ADs
None.
(c) Applicability
This AD applies to General Electric Company GE90-110B1 and GE90-
115B model turbofan engines with:
(1) A high-pressure turbine (HPT) rotor stage 2 disk, part
number (P/N) 2505M73P03, and serial number (S/N) TMT1BA38 or
TMT1BA41, installed; or
(2) a rotating compressor discharge pressure (CDP) HPT seal, P/N
2479M03P01, and S/N GEE1H7GH or GEE1H7JJ, installed.
(d) Subject
Joint Aircraft System Component (JASC) Code 7250, Turbine
Section.
(e) Unsafe Condition
This AD was prompted by the detection of melt-related freckles
in the billet, which may reduce the life limits of certain HPT rotor
stage 2 disks and certain rotating CDP HPT seals. The FAA is issuing
this AD to prevent uncontained release of both the HPT rotor stage 2
disk and the rotating CDP HPT seal. The unsafe condition, if not
addressed, could result in 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
(1) Before the affected HPT rotor stage 2 disk or the rotating
CDP HPT seal listed in Table 1 to paragraph (g) of this AD (``Table
1'') accumulates the cycles since new (CSN) threshold in Table 1, or
at the next engine shop visit, whichever occurs first after the
effective date of this AD, remove the affected part from service and
replace it with a part eligible for installation.
(2) If the affected HPT rotor stage 2 disk or rotating CDP HPT
seal has already exceeded the CSN threshold in Table 1, remove the
affected part before further flight and replace with a part eligible
for installation.
[GRAPHIC] [TIFF OMITTED] TP13AU20.000
(h) Definition
(1) For the purpose of this AD, a part eligible for installation
is any HPT stage 2 disk or rotating CDP HPT seal with an S/N that is
not listed in Table 1 to paragraph (g).
(2) For the purpose of this AD, an engine shop visit is the
induction of an engine into the shop for maintenance involving the
separation of pairs of major mating engine flanges, except that the
separation of engine flanges solely for the purposes of
transportation of the engine without subsequent engine maintenance
does not constitute an engine shop visit.
(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. You may email your
request 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
(1) For more information about this AD, contact Mehdi Lamnyi,
Aerospace Engineer, ECO Branch, FAA, 1200 District Avenue,
Burlington, MA 01803; phone: (781) 238-7743; fax: (781) 238-7999;
email: [email protected].
(2) For service information identified in this AD, contact
General Electric Company, 1 Neumann Way, Cincinnati, OH 45215;
phone: (513) 552-3272; email: [email protected];
website: www.ge.com. 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
781-238-7759.
Issued on August 6, 2020.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification
Service.
[FR Doc. 2020-17594 Filed 8-12-20; 8:45 am]
BILLING CODE 4910-13-P
