[Federal Register Volume 90, Number 183 (Wednesday, September 24, 2025)]
[Rules and Regulations]
[Pages 45907-45909]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2025-18469]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2025-0926; Project Identifier AD-2025-00200-E; 
Amendment 39-23153; AD 2025-19-13]
RIN 2120-AA64


Airworthiness Directives; International Aero Engines AG 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 International Aero Engines AG (IAE AG) Model V2522-A5, V2524-
A5, V2525-D5, V2527-A5, V2527E-A5, V2527M-A5, V2528-D5, V2530-A5, 
V2531-E5, and V2533-A5 engines. This AD was prompted by a manufacturer 
investigation that revealed a quality escape following angled 
ultrasonic inspections (AUSIs) performed on certain high-pressure 
turbine (HPT) 1st-stage hubs and HPT 2nd-stage hubs. This AD requires 
removal and replacement of certain HPT 1st-stage hubs and HPT 2nd-stage 
hubs. The FAA is issuing this AD to address the unsafe condition on 
these products.

DATES: This AD is effective October 29, 2025.

ADDRESSES: 
    AD Docket: You may examine the AD docket at regulations.gov under 
Docket No. FAA-2025-0926; 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: Carol Nguyen, Aviation Safety 
Engineer, FAA, 2200 South 216th Street, Des Moines, WA 98198; phone: 
(781) 238-7655; 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 IAE AG Model 
V2522-A5, V2524-A5, V2525-D5, V2527-A5, V2527E-A5, V2527M-A5, V2528-D5, 
V2530-A5, V2531-E5, and V2533-A5 engines. The NPRM was published in the 
Federal Register on June 13, 2025 (90 FR 25002). The NPRM was prompted 
by a report of a quality escape on HPT 1st-stage hubs and HPT 2nd-stage 
hubs that had AUSIs performed at production. A manufacturer 
investigation of these AUSIs revealed that the quality escape resulted 
from the misinterpretation of the rejection criteria for the AUSIs 
performed on affected HPT 1st-stage hubs and HPT 2nd-stage hubs. In the 
NPRM, the FAA proposed to require removal and replacement of certain 
HPT 1st-stage hubs and HPT 2nd-stage hubs. The FAA is issuing this AD 
to address the unsafe condition on these products.

Discussion of Final Airworthiness Directive

Comments

    The FAA received comments from two commenters. The commenters were 
the Air Line Pilots Association,

[[Page 45908]]

International (ALPA) and an anonymous commenter. ALPA supported the 
NPRM without change. The following presents the comments received on 
the NPRM and the FAA's response to each comment.

Request To Limit Engine Applicability

    An anonymous commenter requested that the FAA limit the 
applicability of the proposed AD to apply only to engine serial numbers 
(S/N) that are known to have incorporated the eight identified affected 
hubs. The commenter stated that limiting the applicability would make 
future compliance checks more efficient and would also eliminate the 
need for repetitive verification across the fleet. The commenter also 
stated that the proposed AD would apply indefinitely to all engines 
within the listed models, which creates an unnecessary and continuing 
compliance burden for maintenance providers and operators in that each 
future engine shop visit will require verification of S/N eligibility 
even though removal will be required within a finite period.
    The FAA disagrees with the request. This final rule includes an 
installation prohibition that currently applies to all models listed in 
the Applicability paragraph of this AD. If the Applicability paragraph 
of this AD is revised to apply only to the engines that currently have 
the affected hubs installed, the installation prohibition will only 
apply to engines that already have affected hubs installed rather than 
all engines. The FAA did not change this AD as a result of this 
comment.

Request To Add Terminating Action

    An anonymous commenter requested that the FAA include a terminating 
action in the proposed AD stating that once all affected hubs are 
removed, the AD would no longer apply to any engines.
    The FAA disagrees with the request because complying with the 
required actions in paragraph (g) of this AD removes the unsafe 
condition and thus provides a terminating action for that portion of 
the AD. In addition, as stated earlier, this AD includes an 
installation prohibition, so removing all affected hubs from service 
does not make the AD no longer applicable. The FAA did not change this 
AD as a result of this comment.

Request To Supersede or Cancel the Proposed AD

    An anonymous commenter requested that the FAA consider superseding 
or cancelling the proposed AD once all suspect parts have been removed 
and no longer create an airworthiness concern. The commenter stated 
that there is an established precedent for terminating or superseding 
ADs once unsafe conditions have been fully mitigated. The FAA infers 
that by cancelling an AD, the commenter is referring to rescinding an 
AD.
    The FAA disagrees with this request. The FAA would not supersede or 
rescind this AD once all suspect parts have been removed because an 
unsafe condition would still exist, as this AD includes an installation 
prohibition and removing all affected hubs from service does not make 
the AD no longer applicable. The FAA did not change this AD as a result 
of this comment.

Conclusion

    The FAA reviewed the relevant data, considered any comments 
received, 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. None of the changes will 
increase the economic burden on any operator.

Costs of Compliance

    The FAA estimates that this AD affects two engines of U.S. 
registry. The FAA estimates that two engines need replacement of the 
HPT 1st-stage hub and no engines need replacement of the HPT 2nd-stage 
hub.
    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
----------------------------------------------------------------------------------------------------------------
Replace HPT 1st-stage hub................  100 work-hours x $85 per        $460,000     $468,500        $937,000
                                            hour = $8,500.
Replace HPT 2nd-stage hub................  100 work-hours x $85 per         360,000      368,500               0
                                            hour = $8,500.
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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.

[[Page 45909]]

Sec.  39.13  [Amended]

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

2025-19-13 International Aero Engines AG: Amendment 39-23153; Docket 
No. FAA-2025-0926; Project Identifier AD-2025-00200-E.

(a) Effective Date

    This airworthiness directive (AD) is effective October 29, 2025.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to International Aero Engines AG (IAE AG) Model 
V2522-A5, V2524-A5, V2525-D5, V2527-A5, V2527E-A5, V2527M-A5, V2528-
D5, V2530-A5, V2531-E5, and V2533-A5 engines.

(d) Subject

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

(e) Unsafe Condition

    This AD was prompted by a manufacturer investigation that 
revealed a quality escape following angled ultrasonic inspections 
performed on certain high-pressure turbine (HPT) 1st-stage hubs and 
HPT 2nd-stage hubs. The FAA is issuing this AD to prevent failure of 
the HPT 1st-stage hub and HPT 2nd-stage hub. The unsafe condition, 
if not addressed, could result in an uncontained hub 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

    For engines with an installed part, part number (P/N) and serial 
number (S/N) identified in table 1 to paragraph (g) of this AD, at 
the next engine shop visit after the effective date of this AD 
before exceeding the applicable removal cycle limit listed in table 
1 to paragraph (g) of this AD or within 100 flight cycles from the 
effective date of this AD, whichever occurs later, remove the 
affected part from service and replace with a part eligible for 
installation.

                     Table 1 to Paragraph (g)--Affected HPT 1st Stage and HPT 2nd Stage Hubs
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                                                                                            Removal cycle limit
                           Part                                  P/N             S/N         (cycles since new)
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HPT 1st-stage hub........................................          2A5001      PKLBSK9287                    100
HPT 1st-stage hub........................................          2A5001      PKLBSS9200                  4,800
HPT 1st-stage hub........................................          2A5001      PKLBST5011                  5,500
HPT 1st-stage hub........................................          2A5001      PKLBST7489                  6,200
HPT 2nd-stage hub........................................          2A4802      PKLBST5005                  4,000
HPT 2nd-stage hub........................................          2A4802      PKLBSS9840                  3,900
HPT 2nd-stage hub........................................          2A4802      PKLBSS0301                  5,000
HPT 2nd-stage hub........................................          2A4802      PKLBSR2100                  6,000
----------------------------------------------------------------------------------------------------------------

(h) Installation Prohibition

    After the effective date of this AD, do not install an HPT 1st-
stage hub or HPT 2nd-stage hub that has a P/N and S/N listed in 
table 1 to paragraph (g) of this AD in any engine.

(i) Definitions

    For the purpose of this AD:
    (1) A ``part eligible for installation'' is an HPT 1st-stage hub 
or HPT 2nd-stage hub having a P/N and S/N that is not listed in 
table 1 to paragraph (g) of this AD.
    (2) An ``engine shop visit'' is the induction of an engine into 
the shop for maintenance involving the separation of any major 
mating engine flanges, H-P, except for the following situations, 
which do not constitute an engine shop visit:
    (i) Separation of engine flanges solely for the purposes of 
transportation without subsequent engine maintenance.
    (ii) Engine removal for the purpose of performing field 
maintenance activities at a maintenance facility in lieu of 
performing them on-wing.

(j) 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 (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) Additional Information

    For more information about this AD, contact Carol Nguyen, 
Aviation Safety Engineer, FAA, 2200 South 216th Street, Des Moines, 
WA 98198; phone: (781) 238-7655; email: [email protected].

(l) Material Incorporated by Reference

    None.

    Issued on September 19, 2025.
Lona C. Saccomando,
Acting Deputy Director, Integrated Certificate Management Division, 
Aircraft Certification Service.
[FR Doc. 2025-18469 Filed 9-23-25; 8:45 am]
BILLING CODE 4910-13-P