[4910-13-P]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2024-0461; Project Identifier AD-2023-00994-E; Amendment 3922767; AD 2024-12-03]
RIN 2120-AA64
Airworthiness Directives; CFE Company Engines
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule.
SUMMARY: The FAA is adopting a new airworthiness directive (AD) for certain CFE
Company (CFE) Model CFE738-1-1B engines. This AD was prompted by a
manufacturer investigation that revealed certain high-pressure turbine (HPT) stage 1 and
stage 2 disks were manufactured from powder metal material suspected to contain iron
inclusion. This AD requires replacement of affected HPT stage 1 and stage 2 disks with
parts eligible for installation. The FAA is issuing this AD to address the unsafe condition
on these products.
DATES: This AD is effective [INSERT DATE 35 DAYS AFTER DATE OF
PUBLICATION IN THE FEDERAL REGISTER].
The Director of the Federal Register approved the incorporation by reference of a
certain publication listed in this AD as of [INSERT DATE 35 DAYS AFTER DATE OF
PUBLICATION IN THE FEDERAL REGISTER].
ADDRESSES:
AD Docket: You may examine the AD docket at regulations.gov under Docket No. FAA2024-0461; 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.
Material Incorporated by Reference:
• For CFE material, contact CFE Company, 111 S. 34th Street, Phoenix, AZ
85034; phone: (800) 601-3099; email: CFE738DataCenter@honeywell.com; website:
aerospace.honeywell.com.
• You may view this material at the FAA, Airworthiness Products Section,
Operational Safety Branch, 1200 District Avenue, Burlington, MA 01803. For
information on the availability of this material at the FAA, call (817) 222-5110. It is also
available at regulations.gov under Docket No. FAA-2024-0461.
FOR FURTHER INFORMATION CONTACT: Alexei Marqueen, Aviation Safety
Engineer, FAA, FAA, 2200 South 216th Street, Des Moines, WA 98198; phone: (781)
238-7178; email: alexei.t.marqueen@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 that apply to certain CFE Model CFE738-1-1B engines
with HPT stage 1 and HPT stage 2 disks installed. The NPRM published in the Federal
Register on March 8, 2024 (89 FR 16710). The NPRM was prompted by a manufacturer
investigation that revealed certain HPT stage 1 and HPT stage 2 disks, installed on
certain CFE738-1-1B model engines, were manufactured from powder metal material
suspected to contain iron inclusion. Further investigation by the manufacturer determined
that the iron inclusion is attributed to deficiencies in the manufacturing process and may
cause reduced material properties and a lower fatigue life capability, which may result in
structural failure. The manufacturer also informed the FAA that additional risk
assessments determined that there were no failed events associated with the discovery of
this iron inclusion material, however concluded that replacement of the affected HPT
stage 1 and HPT stage 2 disks is necessary. In the NPRM, the FAA proposed to require
replacement of affected HPT stage 1 and HPT stage 2 disks with parts 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 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.
Related Material under 1 CFR Part 51
The FAA reviewed CFE Service Bulletin CFE738-72-A8082, dated July 4, 2023,
which specifies the affected part and serial numbers of the HPT stage 1 and stage 2 disks
and specifies replacement instructions for the affected parts. This material 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.
Costs of Compliance
The FAA estimates that this AD affects 29 engines installed on airplanes of U.S.
registry.
The FAA estimates the following costs to comply with this AD:
Estimated costs
Action

Labor Cost

Parts Cost
$78,797

Cost per
product
$79,477

Cost on U.S.
operators
$1,986,925

Replace HPT
stage 1 disk
(25 engines)
Replace HPT
stage 2 disk
(4 engines)

8 work-hours x
$85 per hour =
$680
8 work-hours x
$85 per hour =
$680

$56,268

$56,948

$227,792

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
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:

2024-12-03 CFE Company: Amendment 39-22767; Docket No. FAA-2024-0461;
Project Identifier AD-2023-00994-E.
(a) Effective Date
This airworthiness directive (AD) is effective [INSERT DATE 35 DAYS AFTER
DATE OF PUBLICATION IN THE FEDERAL REGISTER].
(b) Affected ADs
None.
(c) Applicability
This AD applies to CFE Company (CFE) Model CFE738-1-1B engines with an
installed high-pressure turbine (HPT) stage 1 disk or HPT stage 2 disk with a part number
(P/N) and serial number (S/N) identified in Section 1. Planning Information, paragraph E.
Compliance, Tables 2 and 3 of CFE Service Bulletin (SB) CFE738-72-A8082, dated July
4, 2023 (CFE738-72-A8082).
(d) Subject
Joint Aircraft System Component (JASC) Code 7250, Turbine Section.
(e) Unsafe Condition
This AD was prompted by a manufacturer investigation that revealed certain HPT
stage 1 disks and HPT stage 2 disks were manufactured from powder metal material
suspected to contain iron inclusion. The FAA is issuing this AD to prevent premature
fracture and consequent uncontained failure. The unsafe condition, if not addressed,
could result in uncontained debris release, damage to the engine, and damage to the
airplane.
(f) Compliance
Comply with this AD within the compliance times specified, unless already done.
(g) Required Actions
At the applicable times specified in paragraphs (g)(1) and (2) of this AD, remove
each affected HPT stage 1 disk and HPT stage 2 disk from service and replace with a part
eligible for installation, in accordance with steps (1) through (9) in paragraph B. of the
Accomplishment Instructions of CFE738-72-A8082.

(1) For affected HPT stage 1 disks, at the next piece-part exposure or before
exceeding 2,450 cycles since new (CSN), whichever occurs first.
(2) For affected HPT stage 2 disks, at the next piece-part exposure or before
exceeding 2,930 CSN, whichever occurs first.
(h) Definition
For the purpose of this AD:
(1) A “part eligible for installation” is any HPT stage 1 disk or HPT stage 2 disk
with a P/N and S/N that is not identified in Section 1. Planning Information, paragraph E.
Compliance, Tables 2 and 3 of CFE738-72-A8082.
(2) “Piece-part exposure” is when the affected part is removed from the engine.
(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: ANE-ADAMOC@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) Related Information
For more information about this AD, contact Alexei Marqueen, Aviation Safety
Engineer, FAA, 2200 South 216th Steet, Des Moines, WA 98198; phone: (781) 2387178; email: alexei.t.marqueen@faa.gov.
(k) Material Incorporated by Reference
(1) The Director of the Federal Register approved the incorporation by reference
(IBR) of the material listed in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
(2) You must use this material as applicable to do the actions required by this AD,
unless the AD specifies otherwise.

(i) CFE Service Bulletin CFE738-72-A8082, dated July 4, 2023.
(ii) [Reserved]
(3) For CFE material, contact CFE Company, 111 S. 34th Street, Phoenix, AZ
85034; phone: (800) 601-3099; email: CFE738DataCenter@honeywell.com; website:
aerospace.honeywell.com.
(4) You may view this material at the FAA, Airworthiness Products Section,
Operational Safety Branch, 1200 District Avenue, Burlington, MA, 01803. For
information on the availability of this material at the FAA, call (817) 222-5110.
(5) You may view this material at the National Archives and Records
Administration (NARA). For information on the availability of this material at NARA,
visit www.archives.gov/federal-register/cfr/ibr-locations or email
fr.inspection@nara.gov.
Issued on June 11, 2024.

Suzanne Masterson,
Deputy Director, Integrated Certificate Management Division,
Aircraft Certification Service.
[FR Doc. 2024-14939 Filed: 7/8/2024 8:45 am; Publication Date: 7/9/2024]