DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2023-2147; Project Identifier MCAI-2023-00663-E]
Airworthiness Directives; Pratt & Whitney Canada Corp. Engines
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).
SUMMARY: The FAA proposes to adopt a new airworthiness directive
for all Pratt & Whitney Canada Corp. (P&WC) Model PW307A and PW307D
engines. This proposed AD was 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 proposed AD would require
removing from service and replacing certain HPT disks and would also
prohibit installing certain HPT disks on any engine, as specified in a
Transport Canada AD, which is proposed for incorporation by reference
(IBR). The FAA is proposing this AD to address the unsafe condition on
DATES: The FAA must receive comments on this NPRM by December 26,
ADDRESSES: You may send comments, using the procedures found in
11.43 and 11.45, by any of the following methods:
Federal eRulemaking Portal: Go to regulations.gov. Follow
the instructions for submitting comments.
Fax: (202) 493-2251.
Mail: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue SE, Washington, DC 20590.
Hand Delivery: Deliver to Mail address above between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
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 NPRM, the mandatory continuing airworthiness
information (MCAI), any comments received, and other information. The
street address for Docket Operations is listed above.
Material Incorporated by Reference:
For service information identified in this proposed AD,
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;
It is also available at regulations.gov under Docket No. FAA-2023-2147.
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.
FOR FURTHER INFORMATION CONTACT: Barbara Caufield, Aviation Safety
Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590;
phone: (781) 238-7146; email: firstname.lastname@example.org.
The FAA invites you to send any written relevant data, views, or
arguments about this proposal. Send your comments to an address listed
under ADDRESSES. Include ``Docket No. FAA-2023-2147; Project Identifier
MCAI-2023-00663-E'' at the beginning of your comments. The most helpful
comments reference a specific portion of the proposal, explain the
reason for any recommended change, and include supporting data. The FAA
will consider all comments received by the closing date and may amend
this proposal because of those comments.
Except for Confidential Business Information (CBI) as described in
the following paragraph, and other information as described in 14 CFR
11.35, the FAA will post all comments received, without change, to
regulations.gov, including any personal information you provide. The
agency will also post a report summarizing each substantive verbal
contact received about this NPRM.
Confidential Business Information
CBI is commercial or financial information that is both customarily
and actually treated as private by its owner. Under the Freedom of
Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public
disclosure. If your comments responsive to this NPRM contain commercial
or financial information that is customarily treated as private, that
you actually treat as private, and that is relevant or responsive to
this NPRM, it is important that you clearly designate the submitted
comments as CBI. Please mark each page of your submission containing
CBI as ``PROPIN.'' The FAA will treat such marked submissions as
confidential under the FOIA, and they will not be placed in the public
docket of this NPRM. Submissions containing CBI should be sent to
Barbara Caufield, Aviation Safety Engineer, FAA, 1600 Stewart Avenue,
Suite 410, Westbury, NY 11590. Any commentary that the FAA receives
which is not specifically designated as CBI will be placed in the
public docket for this rulemaking.
Transport Canada, which is the aviation authority for Canada, has
issued Transport Canada AD CF-2023-30, dated May 8, 2023 (Transport
Canada AD CF-2023-30) (also referred to as the MCAI), to correct an
unsafe condition on P&WC Model PW307A and PW307D engines with certain
serial numbered HPT disks installed. The MCAI states that on March 18,
2020, an Airbus Model A321-231 airplane, powered by an 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.
You may examine the MCAI in the AD docket at regulations.gov under
Docket No. FAA-2023-2147.
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.
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 is issuing this NPRM after
determining that the unsafe condition described previously is likely to
exist or develop on other products of the same type design.
Explanation of Required Compliance Information
In the FAA's ongoing efforts to improve the efficiency of the AD
process, the FAA developed a process to use some civil aviation
authority (CAA) ADs as the primary source of information for compliance
with requirements for corresponding FAA ADs. The FAA has since
coordinated with other manufacturers and CAAs to use this process. As
result, the FAA proposes to incorporate by reference Transport Canada
AD CF-2023-30 in the FAA final rule. This proposed AD would, therefore,
require compliance with Transport Canada AD CF-2023-30 in its entirety
through that incorporation, except for any differences identified as
exceptions in the regulatory text of this proposed AD. Using common
terms that are the same as the heading of a particular section in the
Transport Canada AD does not mean that operators need comply only with
that section. For example, where the AD requirement refers to
``Compliance,'' compliance with this AD requirement is not limited to
the section titled ``Corrective Actions'' in Transport Canada AD CF-
2023-30. Service information required by the Transport Canada AD for
compliance will be available at regulations.gov under Docket No. FAA-
2023-2147 after the FAA final rule is published.
Proposed AD Requirements in This NPRM
This proposed AD would require accomplishing the actions specified
in the MCAI, except for any differences identified as exceptions in the
regulatory text of this proposed AD.
Costs of Compliance
The FAA estimates that this AD, if adopted as proposed, would
affect 63 engines, installed on airplanes of U.S. registry.
The FAA estimates the following costs to comply with this proposed
|Remove affected HPT 1st or 2nd
||8 work-hours x $85 per
hour = $680
The FAA has included all known costs
in its cost estimate.
According to the manufacturer, however, some of the costs of this
proposed 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.
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
(1) Is not a ``significant regulatory action'' under Executive
(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
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.
Sec. 39.13 [Amended]
2. The FAA amends Sec. 39.13 by adding the following new airworthiness