Rule2021-16766
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 9, 2021
Effective
September 13, 2021
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA is adopting a new airworthiness directive (AD) for all General Electric Company (GE) GE90-110B1 and GE90-115B model turbofan engines. This AD was prompted by an in-service occurrence of loss of engine thrust control resulting in uncommanded high thrust. This AD requires initial and repetitive replacement of the full authority digital engine control (FADEC) integrated circuit (MN4) microprocessor. The FAA is issuing this AD to address the unsafe condition on these products.
Full Text
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<title>Federal Register, Volume 86 Issue 150 (Monday, August 9, 2021)</title>
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[Federal Register Volume 86, Number 150 (Monday, August 9, 2021)]
[Rules and Regulations]
[Pages 43409-43411]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2021-16766]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2021-0347; Project Identifier AD-2020-01610-E;
Amendment 39-21652; AD 2021-15-05]
RIN 2120-AA64
Airworthiness Directives; General Electric Company Turbofan
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 all
General Electric Company (GE) GE90-110B1 and GE90-115B model turbofan
engines. This AD was prompted by an in-service occurrence of loss of
engine thrust control resulting in uncommanded high thrust. This AD
requires initial and repetitive replacement of the full authority
digital engine control (FADEC) integrated circuit (MN4) microprocessor.
The FAA is issuing this AD to address the unsafe condition on these
products.
DATES: This AD is effective September 13, 2021.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of September
13, 2021.
ADDRESSES: For service information identified in this final rule,
contact General Electric Company, 1 Neumann Way, Cincinnati, OH 45215;
phone: (513) 552-3272; email: <a href="/cdn-cgi/l/email-protection#cdacbba4acb9a4a2a3e3aba1a8a8b9beb8bdbda2bfb98daca8e3aaa8e3aea2a0"><span class="__cf_email__" data-cfemail="cbaabda2aabfa2a4a5e5ada7aeaebfb8bebbbba4b9bf8baaaee5acaee5a8a4a6">[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. It is
also available at <a href="https://www.regulations.gov">https://www.regulations.gov</a> by searching for and
locating Docket No. FAA-2021-0347.
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-2021-0347; 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.
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#66351203160e0308482a48230a110f082600070748010910"><span class="__cf_email__" data-cfemail="6c3f18091c04090242204229001b05022c0a0d0d420b031a">[email protected]</span></a>.
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 all GE GE90-110B1 and
GE90-115B model turbofan engines. The NPRM published in the Federal
Register on May 7, 2021 (86 FR 24554). The NPRM was prompted by an in-
service occurrence of loss of engine thrust control resulting in
uncommanded high thrust. The FAA received a report from the
manufacturer of an in-service loss of engine thrust control that
occurred on October 27, 2019, resulting in uncommanded high thrust.
Analysis by the manufacturer found accumulated thermal cycles of the
MN4 integrated circuit in the FADEC, through normal operation, causes
the solder ball joints to wear out and eventually fail over time. The
FAA published AD 2020-20-17 (85 FR 63443, dated October 8, 2020) to
prohibit dispatch of an airplane if certain status messages are
displayed on the engine indicating and crew alerting system and if
certain conditions are present per the manufacturer's service
information. As a terminating action, AD 2020-20-17 also requires
revision of the existing FAA-approved minimum equipment list (MEL) by
incorporating into the MEL the dispatch restrictions listed in AD 2020-
20-17. Since the effective date of AD 2020-20-17, the manufacturer
published GE GE90-100 Service Bulletin (SB) 73-0118 R00, dated November
6, 2020, and Revision 01, dated April 27, 2021, to replace the FADEC
MN4 microprocessor and solder. In the NPRM, the FAA proposed to require
initial and repetitive replacement of the FADEC MN4 microprocessor
using an approved overhaul procedure. 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
Air Line Pilots Association, International (ALPA), Boeing Commercial
Airplanes (Boeing), Cathay Pacific Airways Limited (Cathay), FedEx
Express (FedEx), and United Airlines, Inc. The following presents the
comments received on the NPRM and the FAA's response to each comment.
Request To Revise Installation Prohibition
Cathay requested the FAA revise paragraph (h), Installation
Prohibition, of the NPRM that specifies no more than three replacements
of the FADEC MN4 microprocessor may be performed on the same main
channel board. Cathay suggested that the FAA revise proposed paragraph
(h) to prohibit installation onto any engine of any FADEC that is not
compliant with GE GE90-100 SB 73-0118. Cathay stated that the MN4
processor replacements are managed by the original equipment
manufacturer's (OEM) internal maintenance procedures and operators do
not have visibility into the number of replacements that have been
performed.
The FAA partially agrees. As stated by Cathay, the MN4 processor
replacements are managed by the OEM's internal maintenance procedures
and, therefore, are not necessary in this AD. The FAA has removed
paragraph (h), Installation Prohibition, from this AD. The subsequent
paragraphs of this AD have been redesignated accordingly.
Request To Add Terminating Action
FedEx requested the upcoming FADEC software revision (A085) be
included in this AD as a terminating action. FedEx commented that this
AD may no longer be necessary due to the development and pending
release of GE's new and improved FADEC software upgrade (A085).
The FAA disagrees. The new FADEC software revision (A085) has not
been approved by the FAA. Therefore, this software is not eligible for
installation and cannot be referenced in this AD. The FAA considers
this AD to be an interim action. If terminating action is identified
later, the FAA might consider additional rulemaking. The FAA did not
change this AD.
[[Page 43410]]
Support for the AD
ALPA and Boeing expressed support for the NPRM as written. United
Airlines, Inc. stated they had no objections to the NPRM as proposed.
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 General Electric GE90-100 Service Bulletin (SB)
73-0118, Revision 01, dated April 27, 2021. This SB specifies
procedures for replacing the FADEC MN4 microprocessor. 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.
Interim Action
The FAA considers this AD to be an interim action. If final action
is later identified, the FAA may consider additional rulemaking.
Costs of Compliance
The FAA estimates that this AD affects 311 engines installed on
airplanes of U.S. registry.
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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Remove and replace FADEC.............. 1 work-hour x $85 per $25,200 $25,285 $7,863,635
hour = $85.
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The FAA has included all known costs in its cost estimate.
According to the manufacturer, however, some of the costs of this AD
may be covered under warranty, thereby reducing the cost impact on
affected individuals.
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:
(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:
2021-15-05 General Electric Company: Amendment 39-21652; Docket No.
FAA-2021-0347; Project Identifier AD-2020-01610-E.
(a) Effective Date
This airworthiness directive (AD) is effective September 13,
2021.
(b) Affected ADs
None.
(c) Applicability
This AD applies to General Electric Company (GE) GE90-110B1 and
GE90-115B model turbofan engines.
(d) Subject
Joint Aircraft System Component (JASC) Code 7600, Engine
Controls.
(e) Unsafe Condition
This AD was prompted by an in-service occurrence of loss of
engine thrust control resulting in uncommanded high thrust. The FAA
is issuing this AD to prevent failure of the full authority digital
engine control (FADEC) integrated circuit (MN4) microprocessor
solder ball. The unsafe condition, if not addressed, could result in
loss of engine thrust control and reduced control of the airplane.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Required Actions
(1) Within the following compliance times after the effective
date of this AD, replace the FADEC MN4 microprocessor using an
approved overhaul procedure:
(i) For a FADEC MN4 microprocessor with 10,500 or more cycles
since new (CSN), replace the FADEC MN4 microprocessor before
accumulating 500 additional cycles on the FADEC MN4 microprocessor.
(ii) For a FADEC MN4 microprocessor with 5,000 CSN or more, but
fewer than 10,500 CSN, replace the FADEC MN4 microprocessor at the
next FADEC component shop visit or before accumulating 11,000 CSN on
the FADEC MN4 microprocessor, whichever occurs first.
(2) Thereafter, repeat the replacement of the FADEC MN4
microprocessor at the first FADEC component shop visit after
accumulating 5,000 CSN since the last replacement but before
accumulating 11,000 CSN since the last replacement.
[[Page 43411]]
(h) Definition
(1) For the purpose of this AD, an ``approved overhaul
procedure'' is one of the following:
(i) Replacement of the FADEC MN4 microprocessor using FADEC
International-approved maintenance procedures; or
(ii) Replacement of the FADEC MN4 microprocessor using the
Accomplishment Instructions, paragraph 3.A., of GE GE90-100 Service
Bulletin 73-0118, Revision 01, dated April 27, 2021.
(2) For the purpose of this AD, a ``FADEC component shop visit''
is the induction of the FADEC into a repair facility to perform
internal maintenance on the FADEC.
(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 Related Information. You may email your request to:
<a href="/cdn-cgi/l/email-protection#cd8c8388e08c89e08c80828e8dabacace3aaa2bb"><span class="__cf_email__" data-cfemail="72333c375f33365f333f3d31321413135c151d04">[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
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#dc8fa8b9acb4b9b2f290f299b0abb5b29cbabdbdf2bbb3aa"><span class="__cf_email__" data-cfemail="faa98e9f8a929f94d4b6d4bf968d9394ba9c9b9bd49d958c">[email protected]</span></a>.
(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 Company (GE) GE90-100 Service Bulletin 73-
0118, Revision 01, dated April 27, 2021.
(ii) [Reserved]
(3) For GE 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#e08196898194898f8ece868c858594939590908f9294a08185ce8785ce838f8d"><span class="__cf_email__" data-cfemail="93f2e5faf2e7fafcfdbdf5fff6f6e7e0e6e3e3fce1e7d3f2f6bdf4f6bdf0fcfe">[email protected]</span></a>;
website: <a href="http://www.ge.com">www.ge.com</a>.
(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 (781) 238-7759.
(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: <a href="/cdn-cgi/l/email-protection#b7d1d2d3c5d2d099dbd2d0d6dbf7d9d6c5d699d0d8c1"><span class="__cf_email__" data-cfemail="57313233253230793b3230363b173936253679303821">[email protected]</span></a>, or go to: <a href="https://www.archives.gov/federal-register/cfr/ibr-locations.html">https://www.archives.gov/federal-register/cfr/ibr-locations.html</a>.
Issued on July 9, 2021.
Gaetano A. Sciortino,
Deputy Director for Strategic Initiatives, Compliance & Airworthiness
Division, Aircraft Certification Service.
[FR Doc. 2021-16766 Filed 8-6-21; 8:45 am]
BILLING CODE 4910-13-P
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