DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2023-2147; Project Identifier MCAI-2023-00663-E;
Amendment 39-22670; AD 2024-03-01]
RIN 2120-AA64

Airworthiness Directives; Pratt & Whitney Canada Corp. 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
Pratt & Whitney Canada Corp. (P&WC) Model PW307A and PW307D engines.
This AD is prompted by a root cause analysis of an event involving an
uncontained failure of a high-pressure turbine (HPT) 1st-stage disk
that resulted in high-energy debris penetrating the engine cowling and
an aborted takeoff. This AD requires removing from service and
replacing certain HPT disks and also prohibits installing certain HPT
disks on any engine, as specified in a Transport Canada AD, which is
incorporated by reference. The FAA is issuing this AD to address the
unsafe condition on these products.

DATES: This AD is effective March 27, 2024.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of March 27,
2024.

ADDRESSES:
AD Docket: You may examine the AD docket at regulations.gov under
Docket No. FAA-2023-2147; 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, the mandatory continuing airworthiness
information (MCAI), 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 service information identified in this final rule,
contact Transport Canada, Transport Canada National Aircraft
Certification, 159 Cleopatra Drive, Nepean, Ontario, K1A 0N5, Canada;
phone: (888) 663-3639; email: TC.AirworthinessDirectives-Consignesdenavigabilite.TC@tc.gc.ca; website: tc.canada.ca/en/aviation.
You may view this service information 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-2023-2147.

FOR FURTHER INFORMATION CONTACT: Barbara Caufield, Aviation Safety
Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590;
phone: (781) 238-7146; email: barbara.caufield@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 all P&WC Model PW307A
and PW307D engines. The NPRM published in the Federal Register on
November 9, 2023 (88 FR 77236). The NPRM was prompted by AD CF-2023-30,
dated May 8, 2023 (Transport Canada AD CF-2023-30) (also referred to as
the MCAI), issued by Transport Canada, which is the aviation authority
for Canada. The MCAI states that on March 18, 2020, an Airbus Model
A321-231 airplane, powered by International Aero Engines AG (IAE) Model
V2533-A5 engines, experienced an uncontained HPT 1st-stage disk failure
that resulted in an aborted takeoff and high-energy debris penetrating
the engine cowling.
In response to the March 2020 uncontained HPT 1st-stage disk
failure, the FAA issued a series of ADs, including Emergency AD 2020-
07-51, Amendment 39-21110 (85 FR 20402, April 13, 2020) (AD 2020-07-
51). Since the FAA issued AD 2020-07-51, IAE determined that the
failure of the V2533-A5 engine was due to an undetected subsurface
material defect in the HPT 1st-stage disk that may affect the life of
the part. In coordination with IAE, P&WC performed a records review and
analysis of PW307A and PW307D engine parts made of similar material and
identified additional affected HPT 1st and 2nd-stage disks, installed
on PW307A and PW307D engines. These additional HPT disks may have a
material defect that could reduce the life of the part and must be
removed from service.
In the NPRM, the FAA proposed to require replacing certain HPT
disks and prohibiting the installation of certain HPT disks on any
engine, as specified in the MCAI. The FAA is issuing this AD to address
the unsafe condition on these products.
You may examine the MCAI in the AD docket at regulations.gov under
Docket No. FAA-2023-2147.

Discussion of Final Airworthiness Directive

Comments

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

Conclusion

These products have been approved by the aviation authority of
another country and are approved for operation in the United States.
Pursuant to the FAA's bilateral agreement with this State of Design
Authority, it has notified the FAA of the unsafe condition described in
the MCAI referenced above. 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 Service Information Under 1 CFR Part 51

The FAA reviewed Transport Canada AD CF-2023-30, which identifies
the affected HPT disks and specifies procedures for replacement. This
service information is reasonably available because the interested
parties have access to it through their normal course of business or by
the means identified in ADDRESSES.

Costs of Compliance

The FAA estimates that this AD affects 63 engines installed on
airplanes of U.S. registry.
The FAA estimates the following costs to comply with this AD:

Estimated Costs

The FAA has included all known costs in its cost estimate.
According to the manufacturer, however, some of the costs of this AD
may be covered under warranty, thereby reducing the cost impact on
affected operators.

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.

Sec. 39.13 [Amended]

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