[Federal Register Volume 85, Number 7 (Friday, January 10, 2020)]
[Proposed Rules]
[Pages 1292-1294]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-00020]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2019-0919; Product Identifier 2019-NE-24-AD]
RIN 2120-AA64


Airworthiness Directives; General Electric Company Turbofan 
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 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 turbofan engine models 
with a certain outer shell combustion liner (combustion outer liner 
shell) installed. This proposed AD was prompted by two in-flight engine 
shutdowns (IFSDs) that occurred as a result of failures of the 
combustion outer liner shell. This proposed AD would require a 
borescope inspection (BSI) or visual inspection of the combustion outer 
liner shell and, depending on the results of the inspection, possible 
replacement of the combustion outer liner shell. 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 February 
24, 2020.

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 https://www.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.

[[Page 1293]]

    For service information identified in this NPRM, contact General 
Electric Company, GE Aviation, Room 285, 1 Neumann Way, Cincinnati, OH 
45215; phone: 513-552-3272; email: [email protected]. You 
may view this service information at the FAA, Engine and Propeller 
Standards Branch, 1200 District Avenue, Burlington, MA 01803. For 
information on the availability of this material at the FAA, call 781-
238-7759.

Examining the AD Docket

    You may examine the AD docket on the internet at https://www.regulations.gov by searching for and locating Docket No. FAA-2019-
0919; 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, the regulatory evaluation, any comments received, and other 
information. The street address for Docket Operations is listed above. 
Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Michael Richardson-Bach, Aerospace 
Engineer, ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803; 
phone: 781-238-7747; fax: 781-238-7199; 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 the ADDRESSES section. Include ``Docket No. FAA-2019-0919; 
Product Identifier 2019-NE-24-AD'' at the beginning of your comments. 
The FAA specifically invites comments on the overall regulatory, 
economic, environmental, and energy aspects of this NPRM. The FAA will 
consider all comments received by the closing date and may amend this 
NPRM because of those comments.
    The FAA will post all comments received, without change, to https://www.regulations.gov, including any personal information you provide. 
The FAA will also post a report summarizing each substantive verbal 
contact received about this NPRM.

Discussion

    The FAA received reports of two IFSDs on GE CF34-8C and -8E 
turbofan engine models. These IFSDs were due to the cracking and 
collapsing of the combustion outer liner shell, which resulted in 
thermal distress of the high-pressure turbine and low-pressure turbine 
(LPT) including burn-through of the LPT case. This condition, if not 
addressed, could result in burn-through of the LPT case, engine fire, 
and damage to the airplane.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed GE Alert Service Bulletin (ASB) CF34-8C-AL S/B 72-
A0335, dated June 27, 2019, and GE ASB CF34-8E-AL S/B 72-A0221, dated 
June 27, 2019. The ASBs, differentiated by GE CF34-8 turbofan engine 
model, describe procedures for performing a BSI of the combustion outer 
liner shell. 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 the ADDRESSES section.

FAA's Determination

    The FAA is proposing this AD because it evaluated all the relevant 
information and determined the unsafe condition described previously is 
likely to exist or develop in other products of the same type design.

Proposed AD Requirements

    This proposed AD would require a BSI or visual inspection of the 
combustion outer liner shell and, depending on the results of the 
inspection, possible replacement of the combustion outer liner shell.

Costs of Compliance

    The FAA estimates that this proposed AD affects 1,535 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
----------------------------------------------------------------------------------------------------------------
BSI or visually inspect the           3 work-hours x $85 per               $0            $255           $391,425
 combustion outer liner shell.         hour = $255.
----------------------------------------------------------------------------------------------------------------

    The FAA estimates the following costs to do any necessary 
replacements that would be required based on the results of the 
proposed inspection. The FAA has no way of determining the number of 
engines that might need this replacement:

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                     Cost per
                    Action                                 Labor cost               Parts cost        product
----------------------------------------------------------------------------------------------------------------
Replace the combustion outer liner shell......  812 work-hours x $85 per hour =          $80,000        $149,020
                                                 $69,020.
----------------------------------------------------------------------------------------------------------------

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.

[[Page 1294]]

    This AD is issued in accordance with authority delegated by the 
Executive Director, Aircraft Certification Service, as authorized by 
FAA Order 8000.51C. In accordance with that order, issuance of ADs is 
normally a function of the Compliance and Airworthiness Division, but 
during this transition period, the Executive Director has delegated the 
authority to issue ADs applicable to engines, propellers, and 
associated appliances to the Manager, Engine and Propeller Standards 
Branch, Policy and Innovation Division.

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 (AD):

General Electric Company: Docket No. FAA-2019-0919; Product 
Identifier 2019-NE-24-AD.

(a) Comments Due Date

    The FAA must receive comments by February 24, 2020.

(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 
turbofan engine models with an outer shell combustion liner 
(combustion outer liner shell) part number (P/N) 4124T04G04, P/N 
4124T04G05, or P/N 5159T35G02, installed.

(d) Subject

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

(e) Unsafe Condition

    This AD was prompted by two in-flight engine shutdowns (IFSDs) 
that occurred as a result of failures of the combustion outer liner 
shell. The FAA is issuing this AD to prevent failure of the 
combustion outer liner shell. The unsafe condition, if not 
addressed, could result in burn-through of the low-pressure turbine 
case, engine fire, and damage to the airplane.

(f) Compliance

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

(g) Required Actions

    (1) For an affected engine with a combustion outer liner shell 
that on the effective date of this AD has accumulated 17,500 flight 
hours (FHs) or greater time since new (TSN), or time since repair 
(TSR), perform an initial borescope inspection (BSI) or visual 
inspection of the combustion outer liner shell within 500 engine 
flight hours (FHs) after the effective date of this AD.
    (i) For GE CF34-8C engines, inspect using the Accomplishment 
Instructions, paragraphs 3.A.(4) and 3.A.(5), of GE Alert Service 
Bulletin (ASB) CF34-8C-AL S/B 72-A0335, dated June 27, 2019.
    (ii) For GE CF34-8E engines, inspect using the Accomplishment 
Instructions, paragraphs 3.A.(4) and 3.A.(5), of GE ASB CF34-8E-AL 
S/B 72-A0221, dated June 27, 2019.
    (2) For an affected engine with a combustion outer liner shell 
that on the effective date of this AD has accumulated 17,499 FHs or 
fewer TSN or TSR, within 500 engine FHs after the combustion outer 
liner shell has accumulated 17,500 FHs TSN or TSR, perform an 
initial BSI or visual inspection on the combustion outer liner 
shell.
    (i) For GE CF34-8C engines, inspect using the Accomplishment 
Instructions, paragraphs 3.A.(4) and 3.A.(5), of GE ASB CF34-8C-AL 
S/B 72-A0335, dated June 27, 2019.
    (ii) For GE CF34-8E engines, inspect using accomplishment 
instructions 3.A.(4) and 3.A.(5) of GE ASB CF34-8E-AL S/B 72-A0221, 
dated June 27, 2019.
    (3) For an affected engine with a combustion outer liner shell 
for which it is not possible to determine the TSN or TSR, use the 
engine FHs since new to determine when to perform the BSI or visual 
inspection.
    (4) After the effective date of this AD, and after the initial 
inspection required by paragraph (g)(1) or (2) of this AD, re-
inspect the combustion outer liner shell using inspection criteria 
as follows:
    (i) For GE CF34-8C engines, use Table 1 of GE ASB CF34-8C-AL S/B 
72-A0335, dated June 27, 2019.
    (ii) For GE CF34-8E engines, use Table 1 of GE ASB CF34-8E-AL S/
B 72-A0221, dated June 27, 2019.

(h) Installation Prohibition

    After the effective date of this AD, do not install a combustion 
outer liner shell with greater than 17,500 FHs TSN or TSR without 
first inspecting it in accordance with paragraph (g)(1) of this AD.

(i) Definitions

    For the purpose of this AD, ``time since repair (TSR)'' is the 
amount of FHs accumulated on the combustion outer liner shell since 
performing GEK 105091 or GEK 112031, 72-44-06, REPAIR 023.

(j) 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 (k)(1) of this AD. You may email your 
request 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.

(k) Related Information

    (1) For more information about this AD, contact Michael 
Richardson-Bach, Aerospace Engineer, ECO Branch, FAA, 1200 District 
Avenue, Burlington, MA 01803; phone: 781-238-7747; fax: 781-238-
7199; email: [email protected].
    (2) For service information identified in this AD, contact 
General Electric Company, GE Aviation, Room 285, 1 Neumann Way, 
Cincinnati, OH 45215; phone: 513-552-3272; email: 
[email protected]. You may view this referenced service 
information at the FAA, Engine and Propeller Standards Branch, 1200 
District Avenue, Burlington, MA 01803. For information on the 
availability of this material at the FAA, call 781-238-7759.

    Issued in Burlington, Massachusetts, on January 2, 2020.
Robert J. Ganley,
Manager, Engine & Propeller Standards Branch, Aircraft Certification 
Service.
[FR Doc. 2020-00020 Filed 1-9-20; 8:45 am]
 BILLING CODE 4910-13-P