2024-16473. Airworthiness Directives; CFM International, S.A. Engines

Estimated Costs

Action	Labor cost	Parts cost	Cost per product	Cost on U.S. operators
Visual inspection of HPC stage 2 seal	1 work-hour × $85 per hour = $85	$0	$85	$2,635
Visual inspection of stage 3-4 blisk	1 work-hour × $85 per hour = $85	0	85	2,635
ECI of stage 3-4 blisk	4 work-hours × $85 per hour = $340	0	340	10,540

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

On-Condition Costs

Action	Labor cost	Parts cost	Cost per product
Replacement of HPC stage 2 seal	8 work-hours × $85 per hour = $680	$55,312	$55,992
Replacement of stage 3-4 blisk	8 work-hours × $85 per hour = $680	518,500	519,180

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) Would not affect intrastate aviation in Alaska, and

(3) Would 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

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:

CFM International, S.A.: Docket No. FAA-2024-1898; Project Identifier AD-2023-01013-E.

(a) Comments Due Date

The FAA must receive comments on this airworthiness directive (AD) by September 12, 2024.

(b) Affected ADs

None.

(c) Applicability

This AD applies to CFM International, S.A. (CFM) Model LEAP-1B21, LEAP-1B23, LEAP-1B25, LEAP-1B27, LEAP-1B28, LEAP-1B28B1, LEAP-1B28B2, LEAP-1B28B2C, LEAP-1B28B3, LEAP-1B28BBJ1, and LEAP-1B28BBJ2 engines having an engine serial number (ESN) identified in Table 1 to paragraph (c) of this AD.

Table 1 to Paragraph (c) —Applicable ESNs

ESN	ESN	ESN	ESN	ESN
60A635	60A647	60A662	60A678	60A691
60A639	60A650	60A663	60A679	60A696
60A642	60A653	60A669	60A682	60A702
60A643	60A655	60A670	60A686
60A644	60A656	60A671	60A687
60A645	60A660	60A673	60A689
60A646	60A661	60A676	60A690