90 FR 41 pgs. 11120-11122 - Airworthiness Directives; General Electric Company Engines
Type: RULEVolume: 90Number: 41Pages: 11120 - 11122
Pages: 11120, 11121, 11122Docket number: [Docket No. FAA-2024-2540; Project Identifier AD-2024-00343-E; Amendment 39-22974; AD 2025-05-02]
FR document: [FR Doc. 2025-03383 Filed 3-3-25; 8:45 am]
Agency: Transportation Department
Sub Agency: Federal Aviation Administration
Official PDF Version: PDF Version
[top]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2024-2540; Project Identifier AD-2024-00343-E; Amendment 39-22974; AD 2025-05-02]
RIN 2120-AA64
Airworthiness Directives; General Electric Company Engines
AGENCY:
Federal Aviation Administration (FAA), DOT.
ACTION:
Final rule.
SUMMARY:
The FAA is adopting a new airworthiness directive (AD) for certain General Electric Company (GE) Model CT7-5A2, CT7-5A3, CT7-7A, CT7-7A1, CT7-9B, CT7-9B1, CT7-9B2, CT7-9C, CT7-9C3, CT7-9D, and CT7-9D2 engines. This AD was prompted by the manufacturer's determination that certain GE Model CT7 fleets have affected cooling plates installed that do not meet lifing guidelines. This AD requires replacement of the stage 1 turbine forward cooling plate and the stage 2 turbine aft cooling plate. The FAA is issuing this AD to address the unsafe condition on these products.
DATES:
This AD is effective April 8, 2025.
ADDRESSES:
AD Docket: You may examine the AD docket at regulations.gov under Docket No. FAA-2024-2540; 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:
Sungmo Cho, Aviation Safety Engineer, FAA, 2200 South 216th Street, Des Moines, WA 98198; phone: (781) 238-7241; email: sungmo.d.cho@faa.gov .
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 CT7-5A2, CT7-5A3, CT7-7A, CT7-7A1, CT7-9B, CT7-9B1, CT7-9B2, CT7-9C, CT7-9C3, CT7-9D, and CT7-9D2 engines. The NPRM published in the Federal Register on November 26, 2024 (89 FR 93228). The NPRM was prompted by the manufacturer's determination that certain GE Model CT7 fleets have affected cooling plates installed that do not meet lifing guidelines. In the NPRM, the FAA proposed to require replacement of the stage 1 turbine forward cooling plate and the stage 2 turbine aft cooling plate. 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 the Airline Pilots Association, International. The commenter supported the NPRM without change.
Conclusion
The FAA reviewed the relevant data, considered the comments 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. Except for minor editorial changes, this AD is adopted as proposed in the NPRM.
Costs of Compliance
The FAA estimates that this AD affects 228 engines installed on airplanes of U.S. registry.
The FAA estimates the following costs to comply with this AD:
| Action | Labor cost | Parts cost | Cost per product | Cost on U.S. operators |
|---|---|---|---|---|
| Replace stage 1 turbine forward cooling plate and stage 2 turbine aft cooling plate | 8 work-hours × $85 per hour = $680 | $88,360 | $89,040 | $20,301,120 |
The above costs presume that the installed engine requires replacement of both the stage 1 turbine forward cooling plate and stage 2 turbine aft cooling plate. It is possible that only one of these needs replacement, thus reducing the cost of this AD.
Authority for This Rulemaking
[top] 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
1. The authority citation for part 39 continues to read as follows:
Authority:
49 U.S.C. 106(g), 40113, 44701.
§?39.13 [Amended]
2. The FAA amends §?39.13 by adding the following new airworthiness directive:
2025-05-02 General Electric Company: Amendment 39-22974; Docket No. FAA-2024-2540; Project Identifier AD-2024-00343-E.
(a) Effective Date
This airworthiness directive (AD) is effective April 8, 2025.
(b) Affected ADs
None.
(c) Applicability
This AD applies to General Electric Company (GE) Model CT7-5A2, CT7-5A3, CT7-7A, CT7-7A1, CT7-9B, CT7-9B1, CT7-9B2, CT7-9C, CT7-9C3, CT7-9D, and CT7-9D2 engines with an installed stage 1 turbine forward cooling plate having part number (P/N) 6064T08P01; or with an installed stage 2 turbine aft cooling plate having P/N 6064T07P05 or P/N 6068T36P01.
(d) Subject
Joint Aircraft System Component (JASC) Code 7200, Engine (Turbine/Turboprop).
(e) Unsafe Condition
This AD was prompted by the manufacturer's determination that certain GE Model CT7 fleets have affected cooling plates installed that do not meet lifing guidelines. The FAA is issuing this AD to prevent the failure of the stage 1 turbine forward cooling plate and stage 2 turbine aft cooling plate. The unsafe condition, if not addressed, could result in uncontained engine failure and damage to the airplane.
(f) Compliance
Comply with this AD within the compliance times specified, unless already done.
(g) Required Actions
Within the compliance times specified in paragraphs (g)(1) through (3) of this AD, replace the affected stage 1 turbine forward cooling plate or stage 2 turbine aft cooling plate, as applicable, with a replacement P/N eligible for installation, in accordance with table 1 to the introductory text of paragraph (g) of this AD:
| Engine group | Part name | Affected P/N | Replacement P/N |
|---|---|---|---|
| 1 | Stage 1 turbine forward cooling plate | 6064T08P01 | 6064T08P04. |
| 1 | Stage 2 turbine aft cooling plate | 6064T07P05 | 6064T07P07. |
| 1 | Stage 2 turbine aft cooling plate | 6068T36P01 | 6068T36P04. |
| 2 | Stage 1 turbine forward cooling plate | 6064T08P01 | 6064T08P03 or 6064T08P04. |
| 2 | Stage 2 turbine aft cooling plate | 6064T07P05 | 6064T07P07. |
| 2 | Stage 2 turbine aft cooling plate | 6068T36P01 | 6068T36P04. |
(1) For Group 1 engines with an affected part installed, replace the affected part at the next exposure of the gas generator stator assembly that occurs after the effective date of this AD.
(2) For Group 2 engines with an affected part installed having 7,000 part cycles since new (PCSN) or less as of the effective date of this AD, replace the affected part at the next exposure of the gas generator stator assembly or within 2,000 flight cycles (FCs) but before reaching 7,500 PCSN, whichever occurs first after the effective date of this AD.
(3) For Group 2 engines with an affected part installed having more than 7,000 PCSN as of the effective date of this AD, replace the affected part at the next exposure of the gas generator stator assembly or within 500 FCs, whichever occurs first after the effective date of this AD.
(h) Definitions
For the purpose of this AD:
(1) "Group 1 engines" are GE Model CT7-5A2, CT7-5A3, CT7-9B, CT7-9B1, CT7-9B2, CT7-9D, and CT7-9D2 engines.
(2) "Group 2 engines" are GE Model CT7-7A, CT7-7A1, CT7-9C, and CT7-9C3 engines.
(3) "Exposure of the gas generator stator assembly" is when the gas generator rotor and stator assembly are separated from the combustor module.
(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 and email to: AMOC@faa.gov.
(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 Sungmo Cho, Aviation Safety Engineer, FAA, 2200 South 216th Street, Des Moines, WA 98198; phone: (781) 238-7241; email: sungmo.d.cho@faa.gov.
(k) Material Incorporated by Reference
None.
[top]
Victor Wicklund,
Deputy Director, Compliance & Airworthiness Division, Aircraft Certification Service.
[FR Doc. 2025-03383 Filed 3-3-25; 8:45 am]
BILLING CODE 4910-13-P