Proposed Rule2021-16758
Airworthiness Directives; General Electric Company Turbofan Engines
Primary source
Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.
Published
August 12, 2021
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA proposes to adopt a new airworthiness directive (AD) for certain General Electric Company (GE) GE90 model turbofan engines. This proposed AD was prompted by two separate in-flight shutdowns (IFSDs) resulting from failure of the transfer gearbox (TGB) radial bevel gear (TGB radial gearshaft). This proposed AD would require visual inspection of the TGB radial gearshaft and, depending on the results of the inspection, replacement of the TGB radial gearshaft. The FAA is proposing this AD to address the unsafe condition on these products.
Full Text
<html>
<head>
<title>Federal Register, Volume 86 Issue 153 (Thursday, August 12, 2021)</title>
</head>
<body><pre>
[Federal Register Volume 86, Number 153 (Thursday, August 12, 2021)]
[Proposed Rules]
[Pages 44321-44324]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2021-16758]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2021-0567; Project Identifier AD-2021-00663-E]
RIN 2120-AA64
Airworthiness Directives; General Electric Company Turbofan
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) GE90 model turbofan engines.
This proposed AD was prompted by two separate in-flight shutdowns
(IFSDs) resulting from failure of the transfer gearbox (TGB) radial
bevel gear (TGB radial gearshaft). This proposed AD would require
visual inspection of the TGB radial gearshaft and, depending on the
results of the inspection, replacement of the TGB radial gearshaft. 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
27, 2021.
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.
[[Page 44322]]
For service information identified in this NPRM, contact General
Electric Company, GE Aviation, Room 285, 1 Neumann Way, Cincinnati, OH
45215; phone: (513) 552-3272; email: <a href="/cdn-cgi/l/email-protection#3e5f48575f4a5751501058525b5b4a4d4b4e4e514c4a7e5f5b10595b105d5153"><span class="__cf_email__" data-cfemail="85e4f3ece4f1eceaebabe3e9e0e0f1f6f0f5f5eaf7f1c5e4e0abe2e0abe6eae8">[email protected]</span></a>;
website: <a href="http://www.ge.com">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 (781) 238-7759.
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-2021-0567; 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: Stephen Elwin, Aviation Safety
Engineer, ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803;
phone: (781) 238-7236; fax: (781) 238-7199; email:
<a href="/cdn-cgi/l/email-protection#c695b2a3b6aea3a8e88ae883aab1afa886a0a7a7e8a1a9b0"><span class="__cf_email__" data-cfemail="d784a3b2a7bfb2b9f99bf992bba0beb997b1b6b6f9b0b8a1">[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-2021-0567; Project Identifier
AD-2021-00663-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
Stephen Elwin, 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 of two separate IFSDs resulting from the
failure of the TGB radial gearshaft. After further investigation, the
manufacturer determined that rework on the TGB radial gearshaft teeth
chamfers during manufacturing may have caused local burrs and micro-
cracks which led to high-cycle fatigue failure. GE subsequently issued
service information to provide instructions for a one-time visual
inspection of the affected radial gearshafts for the presence of burrs
or rework on TGB gearshaft teeth chamfers. This condition, if not
addressed, could result in failure of one or more engines, loss of
thrust control, 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 GE90 Service Bulletin (SB) 72-1201 R01, dated
April 28, 2021 (GE90 SB 72-1201 R01), and GE GE90-100 SB 72-0857 R01,
dated April 28, 2021 (GE90-100 SB 72-0857 R01). GE90 SB 72-1201 R01
specifies procedures for performing a one-time inspection of the TGB
radial gearshaft for presence of burrs or rework on teeth chamfers on
GE90-76B, GE90-85B, GE90-90B, and GE90-94B model turbofan engines.
GE90-100 SB 72-0857 R01 specifies procedures for performing a one-time
inspection of the TGB radial gearshaft for presence of burrs or rework
on teeth chamfers on GE90-110B1 and GE90-115B model turbofan engines.
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 visual inspection of the TGB radial
gearshaft and, depending on the results of the inspection, replacement
of the TGB gearshaft.
Differences Between this Proposed AD and the Service Information
GE90 SB 72-1201 R01 and GE90-100 SB 72-0857 R01 identify affected
TGB radial gearshafts with serial numbers (S/Ns) listed in paragraph
4., APPENDIX--A, Table 1, and with serial numbers starting with prefix
FIAAXXXX, FIA05XXX to FIA09XXX, or FIA0AXXX to FIA0NXXX. This AD
applies only to TGB radial gearshafts with S/Ns listed in paragraph 4.,
APPENDIX--A, Table 1 of GE90 SB 72-1201 R01 and GE90-100 SB 72-0857
R01. The FAA determined that TGB radial gearshafts with S/Ns starting
with prefix FIAAXXXX, FIA05XXX to FIA09XXX, or FIA0AXXX to FIA0NXXX are
not required to be inspected and removed as part of this AD. However,
operators may still elect to inspect the TGB radial gearshaft with
these S/Ns at the next scheduled engine shop visit.
Costs of Compliance
The FAA estimates that this AD, if adopted as proposed, would
affect 126 engines installed on airplanes of U.S. registry.
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
----------------------------------------------------------------------------------------------------------------
Inspect TGB radial gearshaft.......... 1 work-hour x $85 per $0 $85 $10,710
hour = $85.
----------------------------------------------------------------------------------------------------------------
[[Page 44323]]
The FAA estimates the following costs to do any necessary
replacement that would be required based on the results of the proposed
inspection. The agency has no way of determining the number of aircraft
that might need this replacement:
On-Condition Costs
----------------------------------------------------------------------------------------------------------------
Cost per
Action Labor cost Parts cost product
----------------------------------------------------------------------------------------------------------------
Replace TGB radial gearshaft.................. 60 work-hours x $85 per hour = $24,520 $29,620
$5,100.
----------------------------------------------------------------------------------------------------------------
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-2021-0567; Project
Identifier AD-2021-00663-E.
(a) Comments Due Date
The FAA must receive comments on this airworthiness directive
(AD) by September 27, 2021.
(b) Affected ADs
None.
(c) Applicability
This AD applies to General Electric Company (GE) GE90-76B, GE90-
85B, GE90-90B, GE90-94B, GE90-110B1, and GE90-115B model turbofan
engines with a transfer gearbox (TGB) radial bevel gear (TGB radial
gearshaft) serial number listed in paragraph 4., APPENDIX--A, Table
1 of GE GE90 Service Bulletin (SB) 72-1201 R01, dated April 28, 2021
(GE90 SB 72-1201 R01) or paragraph 4., APPENDIX--A, Table 1 of GE
GE90-100 SB 72-0857 R01, dated April 28, 2021 (GE90-100 SB 72-0857
R01).
(d) Subject
Joint Aircraft System Component (JASC) Code 7260, Turbine Engine
Accessory Drive.
(e) Unsafe Condition
This AD was prompted by two separate in-flight shutdowns
resulting from the failure of the TGB radial gearshaft. The FAA is
issuing this AD to prevent failure of the TGB radial gearshaft. The
unsafe condition, if not addressed, could result in failure of one
or more engines, loss of thrust control, and damage to the aircraft.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Required Actions
(1) At the next engine shop visit after the effective date of
this AD, perform a visual inspection of the affected TGB radial
gearshaft using the Accomplishment Instructions, paragraph
3.A.(3)(a)1 through 3, of GE90 SB 72-1201 R01 or GE90-100 SB 72-0857
R01, as applicable.
(2) If, during the visual inspection required by paragraph
(g)(1) of this AD, discrepancies are found that meet the criteria in
the Accomplishment Instructions, paragraph 3.A.(4)(a) or 3.A.(4)(b),
of GE90 SB 72-1201 R01 or GE90-100 SB 72-0857 R01, before further
flight, replace the TGB radial gearshaft with a part eligible for
installation.
(h) Definitions
(1) For the purpose of this AD, an ``engine shop visit'' is when
the compressor discharge pressure seal joint is disassembled.
(2) For the purpose of this AD, a ``part eligible for
installation'' is a TGB radial gearshaft that does not have raised
material or rework on the teeth chamfers as described in the
Accomplishment Instructions, paragraph 3.A.(4)(a) or 3.A.(4)(b), of
GE90 SB 72-1201 R01 or GE90-100 SB 72-0857 R01.
(i) Credit for Previous Actions
You may take credit for the inspection of the affected TGB
radial gearshaft required by paragraph (g)(1) of this AD if you
performed the inspection before the effective date of this AD using
GE GE90 SB 72-1201 R00, dated January 5, 2021, or GE GE90-100 SB 72-
0857 R00, dated January 5, 2021.
(j) 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 Related Information. You may email your request to
<a href="/cdn-cgi/l/email-protection#edaca3a8c0aca9c0aca0a2aead8b8c8cc38a829b"><span class="__cf_email__" data-cfemail="43020d066e02076e020e0c00032522226d242c35">[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.
(k) Related Information
(1) For more information about this AD, contact Stephen Elwin,
Aviation Safety Engineer, ECO Branch, FAA, 1200 District Avenue,
Burlington, MA 01803; phone: (781) 238-7236; fax: (781) 238-7199;
email: <a href="/cdn-cgi/l/email-protection#03507766736b666d2d4f2d466f746a6d436562622d646c75"><span class="__cf_email__" data-cfemail="c99abdacb9a1aca7e785e78ca5bea0a789afa8a8e7aea6bf">[email protected]</span></a>.
(2) For service information identified in this AD, contact
General Electric Company, GE Aviation, Room 285, 1 Neumann Way,
[[Page 44324]]
Cincinnati, OH 45215; phone: (513) 552-3272; email:
<a href="/cdn-cgi/l/email-protection#3455425d55405d5b5a1a5258515140474144445b46407455511a53511a575b59"><span class="__cf_email__" data-cfemail="f796819e96839e9899d9919b92928384828787988583b79692d99092d994989a">[email protected]</span></a>; website: <a href="http://www.ge.com">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 (781) 238-7759.
Issued on July 9, 2021.
Gaetano A. Sciortino,
Deputy Director for Strategic Initiatives, Compliance & Airworthiness
Division, Aircraft Certification Service.
[FR Doc. 2021-16758 Filed 8-11-21; 8:45 am]
BILLING CODE 4910-13-P
</pre><script data-cfasync="false" src="/cdn-cgi/scripts/5c5dd728/cloudflare-static/email-decode.min.js"></script></body>
</html>Indexed from Federal Register on August 12, 2021.
This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.