Airworthiness Directives; General Electric Company Engines

[Federal Register Volume 90, Number 48 (Thursday, March 13, 2025)]
[Rules and Regulations]
[Pages 11896-11897]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2025-03987]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2024-2547; Project Identifier AD-2024-00334-E; 
Amendment 39-22987; AD-2025-05-15]
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 all 
General Electric Company (GE) Model CT7-2E1 engines. This AD was 
prompted by a revised analysis using an updated stress model, which 
calculated that the actual life limit of the CT7-2E1 stage 2 turbine 
aft cooling plate is less than the current life limit. This AD requires 
revision of the airworthiness limitations section (ALS) of the existing 
CT7-2E1 engine maintenance manual (EMM) and the operator's existing 
approved maintenance program or inspection program, as applicable, to 
incorporate a reduced life limit for this part. The FAA is issuing this 
AD to address the unsafe condition on these products.

DATES: This AD is effective April 17, 2025.

ADDRESSES: 
    AD Docket: You may examine the AD docket at regulations.gov under 
Docket No. FAA-2024-2547; 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: Barbara Caufield, Aviation Safety 
Engineer, FAA, 2200 South 216th Street, Des Moines, WA 98198 ; phone: 
(781) 238-7146; 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 all GE Model CT7-2E1 
engines. The NPRM published in the Federal Register on December 5, 2024 
(89 FR 96618). The NPRM was prompted by a revised analysis using an 
updated stress model, which calculated that the actual life limit of 
the GE Model CT7-2E1 engine stage 2 turbine aft cooling plate is less 
than the current life limit. In the NPRM, the FAA proposed to require 
revision of the ALS of the existing CT7-2E1 EMM and the operator's 
existing approved maintenance program or inspection program, as 
applicable, to incorporate a reduced life limit for the stage 2 turbine 
aft cooling plate part number 5166T27P01. The FAA is issuing this AD to 
address the unsafe condition on these products.

Discussion of Final Airworthiness Directive

Comments

    The FAA received no comments on the NPRM or on the determination of 
the costs.

Conclusion

    The FAA reviewed the relevant data 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, this AD is adopted as proposed in the NPRM.

Costs of Compliance

    The FAA estimates that this AD affects eight CT7-2E1 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
----------------------------------------------------------------------------------------------------------------
Revise the ALS...........................  1 work-hour x $85 per hour            $0          $85            $680
                                            = $85.
----------------------------------------------------------------------------------------------------------------

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

[[Page 11897]]

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(f), 40113, 44701.


Sec.  39.13  [Amended]

0
2. The FAA amends Sec.  39.13 by adding the following new airworthiness 
directive:

2025-05-15 General Electric Company: Amendment 39-22987; Docket No. 
FAA-2024-2547; Project Identifier AD-2024-00334-E.

(a) Effective Date

    This airworthiness directive (AD) is effective April 17, 2025.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to General Electric Company (GE) Model CT7-2E1 
engines.

(d) Subject

    Joint Aircraft System Component (JASC) Code 7200, Engine 
(Turbine/Turboprop).

(e) Unsafe Condition

    This AD was prompted by a revised analysis using an updated 
stress model, which calculated that the actual life limit of the 
CT7-2E1 stage 2 turbine aft cooling plate is less than the current 
life limit. The FAA is issuing this AD to prevent failure of the 
stage 2 aft turbine cooling plate. The unsafe condition, if not 
addressed, could result in an uncontained failure, release of high-
energy debris, damage to the engine, damage to the airplane, and 
loss of the airplane.

(f) Compliance

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

(g) Required Actions

    Within 30 days after the effective date of this AD, revise the 
airworthiness limitations section of the existing engine maintenance 
manual or instructions for continued airworthiness, and the 
operator's existing approved maintenance program or inspection 
program, as applicable, by replacing the 6,100 cycle life limit with 
the new life limit of 3,100 cycles for the stage 2 aft turbine 
cooling plate part number 5166T27P01.

(h) Provisions for Alternative Actions or Intervals

    After the action required by paragraph (g) of this AD has been 
done, no alternative actions, including life limits, are allowed 
unless they are approved as specified in the provisions of paragraph 
(i) of this AD.

(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 AIR-520 Continued 
Operational Safety Branch, send it to the attention of the person 
identified in paragraph (j) of this AD. Information may be emailed 
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) Additional Information

    For more information about this AD, contact Barbara Caufield, 
Aviation Safety Engineer, FAA, 2200 South 216th Street, Des Moines, 
WA 98198; phone: (781) 238-7146; email: [email protected].

(k) Material Incorporated by Reference

    None.

    Issued on March 7, 2025.
Peter A. White,
Deputy Director, Integrated Certificate Management Division, Aircraft 
Certification Service.
[FR Doc. 2025-03987 Filed 3-12-25; 8:45 am]
BILLING CODE 4910-13-P

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