[Federal Register Volume 89, Number 212 (Friday, November 1, 2024)]
[Proposed Rules]
[Pages 87317-87319]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-25377]


-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2024-2417; Project Identifier AD-2024-00336-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 supersede Airworthiness Directive (AD) 
2020-20-17 and AD 2021-15-05, which apply to all General Electric 
Company (GE) Model GE90-110B1 and GE90-115B engines. AD 2020-20-17 
prohibits dispatch of an airplane if certain status messages are 
displayed on the engine indicating and crew alerting system (EICAS) and 
if certain conditions are present; and as terminating action, requires 
revision of the existing FAA-approved minimum equipment list (MEL) by 
incorporating the dispatch restrictions into the MEL. AD 2021-15-05 
requires initial and repetitive replacement of the full authority 
digital engine control (FADEC) integrated circuit (MN4) microprocessor. 
Since the FAA issued AD 2020-20-17 and AD 2021-15-05, the manufacturer 
has developed a software revision for the electronic engine control 
(EEC) FADEC that further mitigates the unsafe condition. This proposed 
AD would retain all the actions of AD 2020-20-17 and AD 2021-15-05, and 
it would also require upgrading the EEC FADEC software to an EEC FADEC 
software version eligible for installation as a terminating action. 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 December 
16, 2024.

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 regulations.gov. 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.
    AD Docket: You may examine the AD docket at regulations.gov under 
Docket No. FAA-2024-2417; 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:
    <bullet> For GE material identified in this proposed AD, contact 
GE, 1 Neumann Way, Cincinnati, OH 45215; phone: (513) 552-3272; email: 
<a href="/cdn-cgi/l/email-protection#b9d8cfd0d8cdd0d6d797dfd5dcdccdcaccc9c9d6cbcdf985d899d1cbdcdf84" http: ge.com">ge.com</a>">aviation.fleetsupport@ge.com</a>; website: ge.com.
    <bullet> You may view this material 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: Alexander Thickstun, Aviation Safety 
Engineer, FAA, 2200 South 216th Street, Des Moines, WA 98198; phone: 
(202) 267-8292; email: <a href="/cdn-cgi/l/email-protection#fd9c9198859c9399988fd390d38995949e968e898893bd9b9c9cd39a928b"><span class="__cf_email__" data-cfemail="11707d7469707f7574633f7c3f657978727a6265647f517770703f767e67">[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 the ADDRESSES section. Include ``Docket No. FAA-2024-2417; 
Project Identifier AD-2024-00336-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 revise 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 
Alexander Thickstun, 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 issued AD 2020-20-17, Amendment 39-21273 (85 FR 63443, 
October 8, 2020) (``AD 2020-20-17'') and AD 2021-15-05, Amendment 39-
21652 (86 FR 43409, August 9, 2021) (``AD 2021-15-05''), for all GE 
Model GE90-110B1 and GE90-115B engines.
    AD 2020-20-17 was prompted by an in-service occurrence of loss of 
engine thrust control resulting in uncommanded high thrust. AD 2020-20-
17 prohibits dispatch of an airplane if certain status messages are 
displayed on the EICAS and if certain conditions are present; and as 
terminating action, requires revision of the existing FAA-approved MEL 
by incorporating the dispatch restrictions listed in AD 2020-20-17 into 
the MEL. The agency issued AD 2020-20-17 to prevent dispatch of the 
airplane when certain faults caused by degradation of the MN4 
integrated circuit in the FADEC are displayed and certain FADEC 
conditions are present which, if not addressed, could result in loss of 
engine thrust control and reduced control of the airplane.
    AD 2021-15-05 was also prompted by the in-service occurrence of 
loss of engine thrust control resulting in uncommanded high thrust. AD 
2021-15-05 requires initial and repetitive replacement of the FADEC MN4 
microprocessor. The agency issued AD 2021-15-05 to prevent failure of 
the FADEC MN4 microprocessor solder ball which, if not addressed, could 
result in

[[Page 87318]]

loss of engine thrust control and reduced control of the airplane.

Actions Since AD 2020-20-17 and AD 2021-15-05 Were Issued

    Since the FAA issued AD 2020-20-17 and AD 2021-15-05, the 
manufacturer has developed a software revision for the FADEC. The FAA 
has determined that the software revision for the FADEC further 
mitigates the unsafe conditions specified AD 2020-20-17 and AD 2021-15-
05, and therefore, must be required for the affected engines.

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.

Material Incorporated by Reference Under 1 CFR Part 51

    The FAA reviewed GE GE90-100 Service Bulletin 73-0117 R01, dated 
August 5, 2020, which the Director of the Federal Register approved for 
incorporation by reference as of October 23, 2020 (85 FR 63443, October 
8, 2020). This material describes procedures for checking for an 
inbound FADEC EICAS ``ENG EEC C1'' status message and corresponding 
conditions.
    The FAA also reviewed GE GE90-100 Service Bulletin 73-0118, 
Revision 01, dated April 27, 2021, which the Director of the Federal 
Register approved for incorporation by reference as of September 13, 
2021 (86 FR 43409, August 9, 2021). This material specifies procedures 
for replacing the FADEC MN4 microprocessor.
    This material 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 in This NPRM

    This proposed AD would retain all of the requirements of AD 2020-
20-17 and AD 2021-15-05. Furthermore, this proposed AD would require 
upgrading the EEC FADEC software to an EEC FADEC software version that 
is eligible for installation as a terminating action for the retained 
requirements from AD 2020-20-17 and AD 2021-15-05.

Costs of Compliance

    The FAA estimates that this AD, if adopted as proposed, would 
affect 330 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
----------------------------------------------------------------------------------------------------------------
Revise the existing MEL (Retained       1 work-hour x $85 per                 $0             $85         $28,050
 action from AD 2020-20-17).             hour = $85.
Remove and replace FADEC (Retained      1 work-hour x $85 per             25,200          25,285       8,344,050
 action from AD 2021-15-05).             hour = $85.
Upgrade the EEC FADEC software (New     1 work-hour x $85 per                  0              85          28,050
 Action).                                hour = $85.
----------------------------------------------------------------------------------------------------------------

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 that the 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:
0
a. Removing Airworthiness Directives 2020-20-17, Amendment 39-21273 (85 
FR 63443, October 8, 2020); and 2021-15-05, Amendment 39-21652 (86 FR 
43409, August 9, 2021); and
0
b. Adding the following new airworthiness directive:

General Electric Company: Docket No. FAA-2024-2417; Project 
Identifier AD-2024-00336-E.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by December 16, 2024.

(b) Affected ADs

    This AD replaces AD 2020-20-17, Amendment 39-21273 (85 FR 63443, 
October 8, 2020) (AD 2020-20-17); and AD 2021-15-05, Amendment 39-
21652 (86 FR 43409, August 9, 2021) (AD 2021-15-05).

[[Page 87319]]

(c) Applicability

    This AD applies to General Electric Company (GE) Model GE90-
110B1 and GE90-115B engines.

(d) Subject

    Joint Aircraft System Component (JASC) Code 7320, Fuel 
Controlling System.

(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 dispatch of the airplane when certain 
faults caused by degradation of the MN4 integrated circuit in the 
full authority digital engine control (FADEC) are displayed and 
certain FADEC conditions are present, and to prevent failure of the 
electronic engine control (EEC) 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) Retained Actions From AD 2020-20-17

    (1) After October 23, 2020 (the effective date of AD 2020-20-
17), notwithstanding the provisions of the operator's minimum 
equipment list (MEL), dispatch of an airplane is prohibited if the 
engine indicating and crew alerting system (EICAS) displays the 
status message ``ENG EEC C1 L'' or ``ENG EEC C1 R'' and any 
condition is present that is listed in the Accomplishment 
Instructions, paragraphs 3.A.(2)(f), 3.A.3(a), or 3.A.(4) of GE 
GE90-100 Service Bulletin 73-0117 R01, dated August 5, 2020.
    (2) As terminating action for the requirements of paragraph 
(g)(1) of this AD, within 120 days of October 23, 2020 (the 
effective date of AD 2020-20-17), revise the existing FAA-approved 
MEL by incorporating into the MEL the dispatch restrictions listed 
in paragraph (g)(1) of this AD as a required operation or 
maintenance procedure. Specific alternative MEL wording to 
accomplish the actions specified in paragraph (g)(1) of this AD can 
be approved by the operator's principal operations or maintenance 
inspector.

(h) Retained Actions From AD 2021-15-05

    (1) Within the following compliance times after September 13, 
2021 (the effective date of AD 2021-15-05), 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 cycles since the last replacement but before 
accumulating 11,000 cycles since the last replacement.

(i) Retained Definitions From AD 2021-15-05

    For the purpose of this AD:
    (1) 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) A ``FADEC component shop visit'' is the induction of the 
FADEC into a repair facility to perform internal maintenance on the 
FADEC.

(j) New Required Actions

    Within 180 days after the effective date of this AD, replace any 
EEC FADEC software version that is earlier than A.0.8.6 with an EEC 
FADEC software version that is eligible for installation.

(k) Terminating Action

    The actions specified in paragraph (j) of this AD constitute 
terminating action for all the requirements of paragraphs (g) and 
(h) of this AD.

(l) Installation Prohibition

    As of the effective date of this AD, no person may install on 
any engine, an EEC FADEC software version that is earlier than 
A.0.8.6.

(m) Definition

    For the purpose of this AD, an ``EEC FADEC software version that 
is eligible for installation'' is any software version that is 
A.0.8.6 or later.

(n) 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 the AIR-520 Continued 
Operational Safety Branch, send it to the attention of the person 
identified in paragraph (o) of this AD and email to: <a href="/cdn-cgi/l/email-protection#8ccdc1c3cfcceaededa2ebe3fa"><span class="__cf_email__" data-cfemail="99d8d4d6dad9fff8f8b7fef6ef">[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.

(o) Additional Information

    For more information about this AD, contact Alexander Thickstun, 
Aviation Safety Engineer, FAA, 2200 South 216th Street, Des Moines, 
WA 98198; phone: (202) 267-8292; email: 
<a href="/cdn-cgi/l/email-protection#fd9c9198859c9399988fd390d38995949e968e898893bd9b9c9cd39a928b"><span class="__cf_email__" data-cfemail="73121f160b121d1716015d1e5d071b1a10180007061d331512125d141c05">[email protected]</span></a>.

(p) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference (IBR) of the material listed in this 
paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this material as applicable to do the actions 
required by this AD, unless the AD specifies otherwise.
    (3) The following material was approved for IBR on October 23, 
2020 (85 FR 63443, October 8, 2020).
    (i) General Electric Company (GE) GE90-100 Service Bulletin 73-
0117 R01, dated August 5, 2020.
    (ii) [Reserved]
    (4) The following material was approved for IBR on September 13, 
2021 (86 FR 43409, August 9, 2021).
    (i) GE GE90-100 Service Bulletin 73-0118, Revision 01, dated 
April 27, 2021.
    (ii) [Reserved]
    (5) For GE material identified in this AD, contact GE, 1 Neumann 
Way, Cincinnati, OH 45215; phone: (513) 552-3272; email: 
<a href="/cdn-cgi/l/email-protection#1f7e69767e6b7670713179737a7a6b6c6a6f6f706d6b5f237e3f776d7a7922" http: ge.com">ge.com</a>">aviation.fleetsupport@ge.com</a>; website: ge.com.
    (6) You may view this material 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.
    (7) You may view this material at the National Archives and 
Records Administration (NARA). For information on the availability 
of this material at NARA, visit www.archives.gov/federal-register/cfr/ibr-locations or email <a href="/cdn-cgi/l/email-protection#1573673b7c7b66657076617c7a7b557b7467743b727a63"><span class="__cf_email__" data-cfemail="8ceafea2e5e2fffce9eff8e5e3e2cce2edfeeda2ebe3fa">[email protected]</span></a>.

    Issued on October 25, 2024.
Suzanne Masterson,
Deputy Director, Integrated Certificate Management Division, Aircraft 
Certification Service.
[FR Doc. 2024-25377 Filed 10-31-24; 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>