[Federal Register Volume 88, Number 111 (Friday, June 9, 2023)]
[Proposed Rules]
[Pages 37812-37815]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-12286]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2023-1208; Project Identifier AD-2023-00325-E]
RIN 2120-AA64


Airworthiness Directives; General Electric Company 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) Model CF6-80E1A2, CF6-80E1A3, 
CF6-80E1A4, and CF6-80E1A4/B engines. This proposed AD was prompted by 
a manufacturer investigation that revealed that a certain forward outer 
seal and certain high-pressure turbine rotor (HPTR) stage 1

[[Page 37813]]

disks and rotating seals were manufactured from material suspected to 
contain iron inclusion, which may cause reduced material properties and 
a lower fatigue life capability. This proposed AD would require the 
replacement of the affected forward outer seal, HPTR stage 1 disks, and 
rotating 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 July 24, 
2023.

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 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.
    AD Docket: You may examine the AD docket at regulations.gov by 
searching for and locating Docket No. FAA-2023-1208; 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, FAA, 2200 South 216th Street, Des Moines, WA 98198; phone: 
(781) 238-7178; 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 ADDRESSES. Include ``Docket No. FAA-2023-1208; Project Identifier 
AD-2023-00325-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 
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 
Alexei Marqueen, 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 was notified by the manufacturer that a certain forward 
outer seal and certain HPTR stage 1 disks and rotating seals on Model 
CF6-80E1A2, CF6-80E1A3, CF6-80E1A4, and CF6-80E1A4/B engines were made 
from billets manufactured from material that are suspected to contain 
iron inclusion. Such iron inclusion may cause premature fracture and 
subsequent uncontained failure. The FAA has determined that the 
operators with affected HPTR stage 1 disks have proactively removed 
these parts from service. As a result, the proposed compliance time for 
removal and replacement of the affected HPTR stage 1 disks is before 
further flight. This condition, if not addressed, could result in 
uncontained debris release, damage to the engine, 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.

Proposed AD Requirements in This NPRM

    This proposed AD would require the removal of a certain forward 
outer seal and certain HPTR stage 1 disks and rotating seals from 
service and replacement with parts eligible for installation.

Interim Action

    The FAA considers that this proposed AD would be an interim action. 
This unsafe condition 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, if adopted as proposed, would 
affect 1 engine installed on airplanes of U.S. registry. This engine 
would require replacement of the rotating seal. The FAA estimates that 
there are no engines installed on airplanes of U.S. registry that would 
require replacement of the forward outer seal or HPTR stage 1 disk.
    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
----------------------------------------------------------------------------------------------------------------
Replace HPTR stage 1 disk.........  8 work-hours x $85     $1,479,623 (prorated)      $1,480,303              $0
                                     per hour = $680.
Replace rotating seal.............  8 work-hours x $85     $732,517 (prorated)..         733,197         733,197
                                     per hour = $680.
Replace forward outer seal........  8 work-hours x $85     $1,290,000 (prorated)       1,290,680               0
                                     per hour = $680.
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[[Page 37814]]

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-2023-1208; Project 
Identifier AD-2023-00325-E.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by July 24, 2023.

(b) Affected ADs

    None.

 (c) Applicability

    This AD applies to General Electric Company Model CF6-80E1A2, 
CF6-80E1A3, CF6-80E1A4, and CF6-80E1A4/B engines with an installed 
forward outer seal, high-pressure turbine rotor (HPTR) stage 1 disk, 
or rotating seal having a part number (P/N) and serial number (S/N) 
identified in Table 1 to paragraph (c) of this AD.

   Table 1 to Paragraph (c)--Affected Forward Outer Seal, HPTR Stage 1
                        Disks, and Rotating Seals
------------------------------------------------------------------------
           Part name                     P/N               Part S/N
------------------------------------------------------------------------
Forward outer seal.............  1778M70P03........  NCU65340.
HPTR stage 1 disk..............  1863M36G06........  TMT5TD23.
                                                     TMT5TD26.
                                                     TMT5TD27.
Rotating seal..................  1778M69P06........  BTB20610.
                                                     BTB20611.
                                                     BTB20612.
                                                     BTB26650.
------------------------------------------------------------------------

 (d) Subject

    Joint Aircraft System Component (JASC) Code 7250, Turbine 
Section.

 (e) Unsafe Condition

    This AD was prompted by a manufacturer investigation that 
revealed that a certain forward outer seal and certain HPTR stage 1 
disks and rotating seals were manufactured from material suspected 
to contain iron inclusion, which may cause reduced material 
properties and a lower fatigue life capability. The FAA is issuing 
this AD to prevent fracture and subsequent uncontained failure of a 
certain forward outer seal and certain HPTR stage 1 disks and 
rotating seals. The unsafe condition, if not addressed, could result 
in uncontained debris release, 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) At the next piece-part exposure of the affected forward 
outer seal or before the affected forward outer seal exceeds 5,400 
cycles since new (CSN), whichever occurs first after the effective 
date of this AD, remove the affected forward outer seal from service 
and replace with a part eligible for installation.
    (2) At the next piece-part exposure of the affected rotating 
seal or before the affected rotating seal exceeds 5,200 CSN, 
whichever occurs first after the effective date of this AD, remove 
the affected rotating seal from service and replace with a part 
eligible for installation.
    (3) Before further flight after the effective date of this AD, 
remove the affected HPTR stage 1 disk from service and replace with 
a part eligible for installation.

 (h) Definitions

    (1) For the purpose of this AD, a ``part eligible for 
installation'' is any forward outer seal, HPTR stage 1 disk, or 
rotating seal that does not have a P/N and S/N identified in Table 1 
to paragraph (c) of this AD.
    (2) For the purpose of this AD, ``piece-part exposure'' is when 
the affected part is removed from the engine and completely 
disassembled.

 (i) 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 branch, send it to the 
attention of the person identified in paragraph (j) of this AD and 
email 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

    For more information about this AD, contact Alexei Marqueen, 
Aviation Safety Engineer, FAA, 2200 South 216th Street, Des Moines, 
WA 98198; phone: (781) 238-7178; email: [email protected].

[[Page 37815]]

 (k) Material Incorporated by Reference

    None.

    Issued on June 2, 2023.
Michael Linegang,
Acting Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2023-12286 Filed 6-8-23; 8:45 am]
BILLING CODE 4910-13-P


