Document ID: FAA-2019-0766-0007
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: General Electric Company Turbofan Engines
Posted Date: 2022-10-07T04:00Z

[Federal Register Volume 87, Number 194 (Friday, October 7, 2022)]
[Proposed Rules]
[Pages 60944-60947]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-21860]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2019-0766; Project Identifier 2019-NE-23-AD]
RIN 2120-AA64

Airworthiness Directives; General Electric Company Turbofan 
Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Supplemental notice of proposed rulemaking (SNPRM).

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SUMMARY: The FAA is revising a notice of proposed rulemaking (NPRM) 
that applied to all General Electric Company (GE) CF34-8C1, CF34-8C5, 
CF34-8C5A1, CF34-8C5B1, CF34-8C5A2, CF34-8C5A3, CF34-8E2, CF34-8E2A1, 
CF34-8E5, CF34-8E5A1, CF34-8E5A2, CF34-8E6, and CF34-8E6A1 model 
turbofan engines. This action revises the NPRM by updating the service 
information references and removing the initial and repetitive 
fluorescent penetrant inspections (FPIs) of the combustion chamber 
assembly. The FAA is proposing this airworthiness directive (AD) to 
address the unsafe condition on these products. Since these actions 
change the required actions as proposed in the NPRM, the agency is 
requesting comments on this SNPRM.

DATES: The FAA must receive comments on this SNPRM by November 21, 
2022.

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-2019-0766; or in person at 
Docket Operations between 9 a.m. and 5 p.m., Monday through Friday, 
except Federal holidays. The AD docket contains the NPRM, this SNPRM, 
any comments received, and other information. The street address for 
Docket Operations is listed above.
    Material Incorporated by Reference:
     For GE service information identified in this SNPRM, 
contact General Electric Company, 1 Neumann Way, Cincinnati, OH 45215; 
phone: (513) 552-3272; email: ge.com">[email protected]ge.com; website: 
ge.com.
     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 (817) 222-5110.

FOR FURTHER INFORMATION CONTACT: Scott Stevenson, Aviation Safety 
Engineer, ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803; 
phone: (781) 238-7132; 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-2019-0766; Project Identifier 
2019-NE-23-AD'' 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 again 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 proposed AD.

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 SNPRM 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 SNPRM, 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 SNPRM. Submissions containing CBI should 
be sent to Scott Stevenson, 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 issued an NPRM to amend 14 CFR part 39 by adding an AD that 
would apply to all GE CF34-8C1, CF34-8C5, CF34-8C5A1, CF34-8C5B1, CF34-
8C5A2, CF34-8C5A3, CF34-8E2, CF34-8E2A1, CF34-8E5, CF34-8E5A1, CF34-
8E5A2, CF34-8E6, and CF34-8E6A1 (CF34-8C and GE CF34-8E) model turbofan 
engines, including engine models marked on engine data plate as CF34-
8C5/B, CF34-8C5/M, CF34-8C5A1/B, CF34-8C5A1/M, CF34-8C5B1/B, CF34-
8C5A2/B, and CF34-8C5A2/M. The NPRM published in the Federal Register 
on December 3, 2019 (84 FR 66082). The NPRM was prompted by a predicted 
reduction in the cyclic life of the combustion chamber assembly aft 
flange. As a result, the manufacturer added a scheduled maintenance 
check. In the NPRM, the FAA proposed to require revisions to the 
airworthiness limitations section (ALS) of the manufacturer's 
instructions for continued airworthiness and the air carrier's approved 
continued airworthiness maintenance program to

[[Page 60945]]

incorporate initial and repetitive FPIs of the combustion chamber 
assembly.

Actions Since the NPRM Was Issued

    Since the FAA issued the NPRM, the manufacturer incorporated the 
temporary revisions (TRs) into the GE CF34-8C and GE CF34-8E engine 
manuals (EMs). Based on the revised service information, the FAA has 
revised the proposal by removing paragraph (g)(2) from the NPRM, which 
proposed to require initial and repetitive FPIs of the combustion 
chamber assembly installed on GE CF34-8C and GE CF34-8E model turbofan 
engines.

Comments

    The following discussion presents the comments received on the NPRM 
and the FAA's response.

Request To Change References From TRs to EMs

    Horizon Air and Japan Airlines (JAL) requested that the FAA revise 
the references GE CF34-8E EM TR 05-0085, dated February 21, 2019, and 
GE CF34-8E TR 05-0086, dated February 13, 2019, because the TRs have 
since been incorporated into the GE CF34-8C and GE CF34-8E EMs, as 
applicable.
    In response to these comments, the FAA has revised this proposed AD 
by replacing GE CF34-8E EM TR 05-0085, dated February 21, 2019; GE 
CF34-8C TR 05-0141, dated February 21, 2019; GE CF34-8C TR 05-0143, 
dated February 13, 2019; GE CF34-8E TR 05-0086, dated February 13, 
2019; and GE CF34-8C TR 05-0142, dated February 13, 2019, with the 
applicable tasks in the GE CF34-8C or GE CF34-8E EM.

Request To Add FPI Procedure for the Disassembled (Off-Wing) Engine

    JAL requested that the FAA add the FPI procedure to paragraph 
(g)(2)(i) of this proposed AD, as specified in TASK 72-41-01-200-801, 
of GE CF34-8E EM GEK112031 for the disassembled (off-wing) engine. JAL 
reasoned that TASK 05-21-03-200-801 from ESM 05-21-03 Airworthiness 
Limitations--Mandatory Inspection 001, of GE CF34-8E EM GEK112031, 
which incorporated GE CF34-8E TR 05-0086, dated February 13, 2019, 
refers to TASK 72-41-01-200-801, on-wing inspections.
    The FAA disagrees with the request to add disassembled or off-wing 
FPI procedures to this proposed AD. Since TASK 72-41-01-200-801 and 
TASK 72-41-01-200-801 are not referenced in GE CF34-8E EM GEK112031, 
the FAA interprets JAL's comment as a request to add TASK 72-00-41-200-
806, as referenced in GE CF34-8E EM GEK112031. Additionally, the FAA 
has determined that the FPIs proposed in the NPRM are not required to 
address the unsafe condition. Therefore, the FAA has removed the 
proposed FPI of the combustion chamber assembly, paragraph (g)(2), as 
proposed in the NPRM, from this proposed SNPRM.

Support for the AD

    The Air Line Pilots Association, International expressed support 
for the AD as written.

FAA's Determination

    The FAA is proposing this AD after determining the unsafe condition 
described previously is likely to exist or develop in other products of 
the same type design. Certain changes described above revise the scope 
of the NPRM. As a result, it is necessary to reopen the comment period 
to provide additional opportunity for the public to comment on this 
SNPRM.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed the following tasks:
     TASK 05-11-05-200-801, dated March 4, 2021, from ESM 05-
11-05 Static Structures--Life Limits, of GE CF34-8C EM GEK105091, Rev 
51, dated April 1, 2022;
     TASK 05-11-05-200-801, dated March 4, 2021, from ESM 05-
11-05 Static Structures--Life Limits, of GE CF34-8E EM GEK112031, Rev 
43, dated April 1, 2022; and
     TASK 05-11-25-200-801, dated November 3, 2020, from ESM 
05-11-25 Static Structures--BJ Life Limits, of GE CF34-8C EM GEK105091, 
Rev 51, dated April 1, 2022.
    These tasks, differentiated by GE CF34-8 turbofan engine model, 
identify the combustion chamber assembly part number, life limit 
cycles, and revised inspections.
    The FAA also reviewed the following tasks:
     TASK 05-21-03-200-801, dated April 1, 2019, from ESM 05-
21-03 Airworthiness Limitations--Mandatory Inspection 001, of GE CF34-
8C EM GEK105091, Rev 51, dated April 1, 2022; and
     TASK 05-21-03-200-801, dated April 1, 2019, from ESM 05-
21-03 Airworthiness Limitations--Mandatory Inspection 001, of GE CF34-
8E EM GEK112031, Rev 43, dated April 1, 2022.
    These tasks, differentiated by GE CF34-8 turbofan engine model, 
describe revised inspection threshold limits and re-inspection interval 
limits for the combustion chamber assembly.
    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 SNPRM

    This proposed AD would require revisions to the ALS of the existing 
EM and the operator's existing approved maintenance or inspection 
program, as applicable, to incorporate initial and repetitive FPIs of 
the combustion chamber assembly, except as discussed under 
``Differences Between this proposed SNPRM and the Service 
Information.''

Differences Between This SNPRM and the Service Information

    TASK 05-21-03-200-801 of the GE CF34-8E EM GEK112031 and GE CF34-8C 
EM GEK105091, both dated April 1, 2022, specify to perform the 
inspection from the issuance date of the TR. This SNPRM would require 
performing the inspection after the effective date of this AD.

Costs of Compliance

    The FAA estimates that this proposed AD affects 1,633 GE CF34-8C 
turbofan engine models and 857 GE CF34-8E turbofan engine models 
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 ALS of the EM and            1 work-hour x $85 per                 $0             $85        $211,650
 operator's existing approved            hour = $85.
 maintenance or inspection program (GE
 CF34-8C and CF34-8E).
----------------------------------------------------------------------------------------------------------------

[[Page 60946]]

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) 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 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-2019-0766; Project 
Identifier 2019-NE-23-AD.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by November 21, 2022.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to General Electric Company (GE) CF34-8C1, CF34-
8C5, CF34-8C5A1, CF34-8C5B1, CF34-8C5A2, CF34-8C5A3, CF34-8E2, CF34-
8E2A1, CF34-8E5, CF34-8E5A1, CF34-8E5A2, CF34-8E6, and CF34-8E6A1 
model turbofan engines, including engine models marked on engine 
data plate as CF34-8C5/B, CF34-8C5/M, CF34-8C5A1/B, CF34-8C5A1/M, 
CF34-8C5B1/B, CF34-8C5A2/B, and CF34-8C5A2/M.

(d) Subject

    Joint Aircraft System Component (JASC) Code 7240, Turbine Engine 
Combustion Section.

(e) Unsafe Condition

    This AD was prompted by a predicted reduction in the cyclic life 
of the combustion chamber assembly aft flange. The FAA is issuing 
this AD to prevent failure of the combustion chamber assembly. The 
unsafe condition, if not addressed, could result in combustion 
chamber assemblies failing before reaching their published life 
limit, uncontained release of the combustion chamber assembly, 
damage to the engine, and damage to the airplane.

(f) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

(g) Required Actions

    Within 90 days after the effective date of this AD, revise the 
airworthiness limitations section (ALS) of the existing engine 
manual (EM) and the operator's existing approved maintenance or 
inspection program, as applicable, to incorporate the following 
requirements for fluorescent penetrant inspections of the combustion 
chamber assembly aft flange.
    (1) For combustion chamber assemblies with part numbers (P/Ns) 
4145T11G08, 4145T11G09, 4180T27G01, or 4180T27G03 installed on GE 
CF34-8E model turbofan engines:
    (i) Replace Table 801, Static Structures--Life Limits (Table 
801), with the revised Table 801 in TASK 05-11-05-200-801, dated 
March 4, 2021, from ESM 05-11-05 Static Structures--Life Limits 
(TASK 05-11-05-200-801), of GE CF34-8E EM GEK112031, Rev 43, dated 
April 1, 2022 (GE CF34-8E EM GEK112031), and
    (ii) Add TASK 05-21-03-200-801, dated April 1, 2019, including 
the note, from ESM 05-21-03 Airworthiness Limitations--Mandatory 
Inspection 001 (TASK 05-21-03-200-801), of GE CF34-8E EM GEK112031. 
Where TASK 05-21-03-200-801 of GE CF34-8E EM GEK112031 specifies to 
perform the inspection within 2,200 cycles from the issuance date of 
the temporary revision (TR), this AD requires performing the 
inspection within 2,200 cycles from the effective date of this AD.
    (2) For combustion chamber assemblies with P/Ns 4126T87G04, 
4126T87G05, 4126T87G07, 4126T87G08, 4180T27G04, 4923T82G01, or 
4923T82G02 installed on GE CF34-8C1 model turbofan engines, or with 
P/Ns 4145T11G08, 4145T11G10, 4180T27G02, 4180T27G04, or 4923T82G02 
installed on GE CF34-8C5, CF34-8C5/M, CF34-8C5A1, CF34-8C5A1/M, 
CF34-8C5A2, CF34-8C5A2/M, CF34-8C5A3, or CF34-8C5B1 model turbofan 
engines:
    (i) Replace Table 801 (For -8C1) and Table 802 (For -8C5) Static 
Structures--Life Limits (Table 801 and Table 802), with the revised 
Table 801 in TASK 05-11-05-200-801 and Table 802 in TASK 05-11-25-
200-801, dated November 3, 2020, from ESM 05-11-25 Static 
Structures--BJ Life Limits (TASK 05-11-25-200-801), of GE CF34-8C EM 
GEK105091, Rev 51, dated April 1, 2022 (GE CF34-8C EM GEK105091); 
and
    (ii) Add TASK 05-21-03-200-801, dated April 1, 2019, including 
the note, from ESM 05-21-03 Airworthiness Limitations--Mandatory 
Inspection 001 (TASK 05-21-03-200-801), of GE CF34-8C EM GEK105091. 
Where TASK 05-21-03-200-801 of GE CF34-8C EM GEK105091 specifies to 
perform the inspection within 2,200 cycles from the issuance date of 
the TR, this AD requires performing the inspection within 2,200 
cycles from the effective date of this AD.
    (3) For combustion chamber assemblies with P/Ns 4145T11G08, 
4145T11G10, 4180T27G02, 4180T27G04, or 4923T82G02 installed on GE 
CF34-8C5B1/B, CF34-8C5/B, CF34-8C5A1/B, or CF34-8C5A2/B model 
turbofan engines:
    (i) Replace Table 801 (For/B -8C5) Static Structures--Life 
Limits with the revised Table 801 in TASK 05-11-25-200-801, of GE 
CF34-8C EM GEK105091; and
    (ii) Add TASK 05-21-03-200-801, including the note, of GE CF34-
8C EM GEK105091. Where TASK 05-21-03-200-801 of GE CF34-8C EM 
GEK105091 specifies to perform the inspection within 2,200 cycles 
from the issuance date of the TR, this AD requires performing the 
inspection within 2,200 cycles from the effective date of this AD.
    (4) After performing the actions required by paragraphs (g)(1) 
through (3) of this AD, except as provided in paragraph (i) of this 
AD, no alternative life limits may be approved.

(h) Credit for Previous Actions

    You may take credit for revising the ALS of the existing EM and 
the operator's existing approved maintenance or inspection program, 
as applicable, required by paragraphs (g)(1) through (3) of this AD 
if the actions were completed before the effective date of this AD 
using GE CF34-8E EM TR

[[Page 60947]]

05-0085, dated February 21, 2019; GE CF34-8C TR 05-0141, dated 
February 21, 2019; GE CF34-8C TR 05-0143, dated February 13, 2019; 
GE CF34-8E TR 05-0086, dated February 13, 2019; or GE CF34-8C TR 05-
0142, dated February 13, 2019.

(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 paragraph (j) of this AD and email it 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 Scott Stevenson, 
Aviation Safety Engineer, ECO Branch, FAA, 1200 District Avenue, 
Burlington, MA 01803; phone: (781) 238-7132; email: 
[email protected].

(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) TASK 05-11-05-200-801, dated March 4, 2021, from ESM 05-11-
05 Static Structures--Life Limits, of GE CF34-8C EM GEK105091, Rev 
51, dated April 1, 2022.
    (ii) TASK 05-11-05-200-801, dated March 4, 2021, from ESM 05-11-
05 Static Structures--Life Limits, of GE CF34-8E EM GEK112031, Rev 
43, dated April 1, 2022.
    (iii) TASK 05-11-25-200-801, dated November 3, 2020, from ESM 
05-11-25 Static Structures--BJ Life Limits, of GE CF34-8C EM 
GEK105091, Rev 51, dated April 1, 2022.
    (iv) TASK 05-21-03-200-801, dated April 1, 2019, from ESM 05-21-
03 Airworthiness Limitations--Mandatory Inspection 001, of GE CF34-
8C EM GEK105091, Rev 51, dated April 1, 2022.
    (v) TASK 05-21-03-200-801, dated April 1, 2019, from ESM 05-21-
03 Airworthiness Limitations--Mandatory Inspection 001, of GE CF34-
8E EM GEK112031, Rev 43, dated April 1, 2022.
    (3) For GE service information identified in this AD, contact 
General Electric Company, 1 Neumann Way, Cincinnati, OH 45215; 
phone: (513) 552-3272; email: ge.com">[email protected]ge.com; website: 
ge.com.
    (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 (817) 222-5110.
    (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: [email protected], or go to: www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued on October 3, 2022.
Christina Underwood,
Acting Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2022-21860 Filed 10-6-22; 8:45 am]
BILLING CODE 4910-13-P