Airworthiness Directives; General Electric Company Engines

[Federal Register Volume 88, Number 177 (Thursday, September 14, 2023)]
[Rules and Regulations]
[Pages 63014-63016]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-19793]


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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; 
Amendment 39-22545; AD 2023-18-04]
RIN 2120-AA64


Airworthiness Directives; General Electric Company 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 
certain General Electric Company (GE) Model CF6-80E1A2, CF6-80E1A3, 
CF6-80E1A4, and CF6-80E1A4/B engines. This AD was prompted by a 
manufacturer investigation that revealed that a certain forward outer 
seal and certain high-pressure turbine rotor (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. This AD requires the replacement of the 
affected forward outer seal, HPTR stage 1 disks, and rotating seals. 
The FAA is issuing this AD to address the unsafe condition on these 
products.

DATES: This AD is effective October 19, 2023.

ADDRESSES: 
    AD Docket: You may examine the AD docket at regulations.gov under 
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 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: Alexei Marqueen, Aviation Safety 
Engineer, FAA, 2200 South 216th Street, Des Moines, WA 98198; phone: 
(781) 238-7178; email: [email protected].

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 certain GE Model CF6-
80E1A2, CF6-80E1A3, CF6-80E1A4, and CF6-80E1A4/B engines. The NPRM 
published in the Federal Register on June 9, 2023 (88 FR 37812). The 
NPRM was prompted by a report from the manufacturer that a certain 
forward outer seal and certain HPTR stage 1 disks and rotating seals 
were made from billets manufactured from material that is 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 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. In the NPRM, the FAA proposed to 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. 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 two commenters. The commenters were 
Delta Air Lines, Inc. (DAL) and EVA Air. The following presents the 
comments received on the NPRM and the FAA's response to each comment.

No Affected Parts

    EVA Air commented that its fleet does not have any affected parts. 
The FAA acknowledges this comment.

Request To Expand Applicability and Add Parts Prohibition Requirement

    DAL commented that according to the engine illustrated parts 
catalog, the R88DT rotor on the CF6-80E1 fleet of engines could be 
installed on the CF6-80C2 fleet of engines, specifically on the -B2F, -
B4F, -B6F, -B7F, and -B8F variants. The commenter reasoned that without 
a part installation prohibition in the proposed AD, the affected parts 
would be eligible for installation on the non-CF6-80E1 engines after 
the required removal action in the AD. DAL requested that the FAA 
revise the proposed AD to add certain engine variants to paragraph (c), 
Applicability, and to add a parts installation prohibition to paragraph 
(g), Required Actions, to prevent installation of the removed parts on 
non-CF6-80E1 engines.
    The FAA disagrees. This AD applies to engine models known to have 
affected parts installed. Paragraph (g) of this AD requires the removal 
of the affected parts from service. Since the FAA and the manufacturer 
know where these parts are, and parts removed from service by AD action 
are not serviceable and not eligible for re-installation on any engine, 
it is not necessary to revise paragraph (c) of this AD to add engine 
variants and revise paragraph (g) of this AD to prohibit installation 
of the removed parts. Additionally, adding new engine variants to this 
AD would delay final issuance of this AD, as such a change would 
increase the scope of this AD, requiring new notice and comment. We may 
consider separate rulemaking, however. The FAA did not change this AD 
as a result of these comments.

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.

Interim Action

    The FAA considers this AD to 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 affects 1 engine installed on 
airplanes of U.S. registry. This engine requires replacement of the 
rotating seal. The FAA estimates that there are no engines installed on 
airplanes of U.S. registry that requires replacement of the forward 
outer seal or HPTR stage 1 disk.
    The FAA estimates the following costs to comply with this AD:

[[Page 63015]]



                                                 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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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:

2023-18-04 General Electric Company: Amendment 39-22545; Docket No. 
FAA-2023-1208; Project Identifier AD-2023-00325-E.

(a) Effective Date

    This airworthiness directive (AD) is effective October 19, 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.

[[Page 63016]]

(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].

(k) Material Incorporated by Reference

    None.

    Issued on September 7, 2023.
Ross Landes,
Deputy Director for Regulatory Operations, Compliance & Airworthiness 
Division, Aircraft Certification Service.
[FR Doc. 2023-19793 Filed 9-13-23; 8:45 am]
BILLING CODE 4910-13-P

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