Airworthiness Directives; General Electric Company Turbofan Engines

[Federal Register Volume 87, Number 195 (Tuesday, October 11, 2022)]
[Rules and Regulations]
[Pages 61236-61237]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-21861]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2022-0977; Project Identifier AD-2022-00419-E; 
Amendment 39-22205; AD 2022-21-06]
RIN 2120-AA64


Airworthiness Directives; General Electric Company Turbofan 
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) CF34-8C and CF34-8E model 
turbofan engines. This AD was prompted by a report of a crack found on 
the low-pressure turbine (LPT) stage 5 disk at the forward arm area. 
This AD requires the removal of the affected LPT stage 5 disk and 
replacement with a part eligible for installation. The FAA is issuing 
this AD to address the unsafe condition on these products.

DATES: This AD is effective November 15, 2022.

ADDRESSES: 
    AD Docket: You may examine the AD docket at regulations.gov by 
searching for and locating Docket No. FAA-2022-0977; 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:  Scott Stevenson, Aviation Safety 
Engineer, ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803; 
phone: (781) 238-7132; 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 CF34-8C1, 
CF34-8C5, CF34-8C5A1, CF34-8C5A2, CF34-8C5A3, CF34-8C5B1, CF34-8E2, 
CF34-8E2A1, CF34-8E5, CF34-8E5A1, CF34-8E5A2, CF34-8E6, and CF34-8E6A1 
model turbofan engines. The NPRM published in the Federal Register on 
August 1, 2022 (87 FR 46906). The NPRM was prompted by a report of a 
crack found on the LPT stage 5 disk at the forward arm area. In the 
NPRM, the FAA proposed to require the removal of the affected LPT stage 
5 disk and replacement with a part 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 one comment from Air Line Pilots Association, 
International (ALPA). ALPA supported the NPRM without change.

Conclusion

    The FAA reviewed the relevant data, considered the comment 
received, and determined that air safety requires adopting the AD as 
proposed. Accordingly, the FAA is issuing this AD to address the unsafe 
condition on these products. This AD is adopted as proposed in the 
NPRM.

Related Service Information

    The FAA reviewed GE CF34-8C Service Bulletin (SB) 72-0352 R00, 
dated September 20, 2021, and GE CF34-8E SB 72-0240 R00, dated 
September 20, 2021. These SBs, differentiated by engine model, describe 
procedures for removing and replacing the affected LPT stage 5 disk, 
part number (P/N) 4117T14P02, with a new LPT stage 5 disk, P/N 
4117T14P03.

Costs of Compliance

    The FAA estimates that this AD affects 112 engines installed on 
airplanes of U.S. registry.
    The FAA estimates the following costs to comply with this AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                     Cost per      Cost on U.S.
              Action                      Labor Cost             Parts Cost           product        operators
----------------------------------------------------------------------------------------------------------------
Remove and replace the LPT stage 5  2 work-hours x $85     $30,500 (pro-rated)..         $30,670      $3,435,040
 disk.                               per hour = $170.
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[[Page 61237]]

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:

2022-21-06 General Electric Company: Amendment 39-22205; Docket No. 
FAA-2022-0977; Project Identifier AD-2022-00419-E.

(a) Effective Date

    This airworthiness directive (AD) is effective November 15, 
2022.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to General Electric Company CF34-8C1, CF34-8C5, 
CF34-8C5A1, CF34-8C5A2, CF34-8C5A3, CF34-8C5B1, CF34-8E2, CF34-
8E2A1, CF34-8E5, CF34-8E5A1, CF34-8E5A2, CF34-8E6, and CF34-8E6A1 
model turbofan engines with an installed low-pressure turbine (LPT) 
stage 5 disk, part number (P/N) 4117T14P02.

(d) Subject

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

(e) Unsafe Condition

    This AD was prompted by a report of a crack found on the LPT 
stage 5 disk at the forward arm area. The FAA is issuing this AD to 
prevent failure of the LPT stage 5 disk. 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) Required Actions

    During the next piece-part exposure after the affected LPT stage 
5 disk accumulates 8,000 cycles since new (CSN), remove the affected 
LPT stage 5 disk and replace with a part eligible for installation.

(h) Installation Prohibition

    Do not install an affected LPT stage 5 disk with 8,000 CSN or 
more into the LPT module of the engine.

(i) Definitions

    (1) For the purpose of this AD, a ``part eligible for 
installation'' is an LPT stage 5 disk, P/N 4117T14P03, or later 
approved P/N.
    (2) For the purpose of this AD, ``piece-part exposure'' is when 
the LPT module is separated from the engine and the LPT stage 5 
blades are removed from the LPT stage 5 disk.

(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) 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.

(k) 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].

(l) Material Incorporated by Reference

    None.

    Issued on October 3, 2022.
Christina Underwood,
Acting Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2022-21861 Filed 10-7-22; 8:45 am]
BILLING CODE 4910-13-P

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