[Federal Register Volume 89, Number 50 (Wednesday, March 13, 2024)]
[Rules and Regulations]
[Pages 18350-18353]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-05238]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2024-0458; Project Identifier MCAI-2024-00116-E; 
Amendment 39-22694; AD 2024-04-51]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney Canada Corp. Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule; request for comments.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for all 
Pratt & Whitney Canada Corp. (P&WC) Model PT6A-64, PT6A-66, PT6A-66A, 
PT6A-66B, PT6A-66D, PT6A-67, PT6A-67A, PT6A-67AF, PT6A-67AG, PT6A-67B, 
PT6A-67D, PT6A-67F, PT6A-67P, PT6A-67R, PT6A-67RM, PT6A-67T, PT6A-68, 
PT6A-68D, PT6E-67XP, and PT6E-66XT engines. The FAA previously sent 
this AD as an emergency AD to all known U.S. owners and operators of 
these engines. This AD was prompted by reports of second-stage power 
turbine (PT2) blade failures. This AD requires removal of affected PT2 
blades prior to the next flight and prohibits installation of affected 
PT2 blades, as specified in a Transport Canada Emergency 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 28, 2024. Emergency AD 2024-04-51, 
issued on February 16, 2024, which contained the requirements of this 
amendment, was effective with actual notice.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication identified in this AD as of March 
28, 2024.
    The FAA must receive comments on this AD by April 29, 2024.

ADDRESSES: You may send comments, using the procedures found in 14 CFR 
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-2024-0458; 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 
street address for Docket Operations is listed above.
    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: [email protected]; website: tc.canada.ca/en/aviation.
     You may view this material at the FAA, Airworthiness 
Products Section,

[[Page 18351]]

Operational Safety Branch, 2200 South 216th Street, Des Moines, WA. 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-
2024-0458.

FOR FURTHER INFORMATION CONTACT: Barbara Caufield, Aviation Safety 
Engineer, FAA, 2200 South 216th Street, Des Moines, WA 98198; phone: 
(781) 238-7146; email: [email protected].

SUPPLEMENTARY INFORMATION:

Comments Invited

    The FAA invites you to send any written data, views, or arguments 
about this final rule. Send your comments to an address listed under 
ADDRESSES. Include ``Docket No. FAA-2024-0458; Project Identifier MCAI-
2024-00116-E'' at the beginning of your comments. The most helpful 
comments reference a specific portion of the final rule, 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 final rule 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 final rule.

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 AD 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 AD, 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 AD. Submissions containing CBI should be sent to Barbara 
Caufield, Aviation Safety Engineer, FAA, 2200 South 216th Street, Des 
Moines, WA 98198. Any commentary that the FAA receives which is not 
specifically designated as CBI will be placed in the public docket for 
this rulemaking.

Background

    The FAA issued Emergency AD 2024-04-51, dated February 16, 2024 
(the emergency AD), to address an unsafe condition on P&WC Model PT6A-
64, PT6A-66, PT6A-66A, PT6A-66B, PT6A-66D, PT6A-67, PT6A-67A, PT6A-
67AF, PT6A-67AG, PT6A-67B, PT6A-67D, PT6A-67F, PT6A-67P, PT6A-67R, 
PT6A-67RM, PT6A-67T, PT6A-68, PT6A-68D, PT6E-67XP, and PT6E-66XT 
engines. The FAA sent the emergency AD to all known U.S. owners and 
operators of these engines. The emergency AD requires removal of 
affected PT2 blades prior to the next flight. The emergency AD also 
prohibits installation of affected PT2 blades.
    The emergency AD was prompted by Transport Canada Emergency AD CF-
2024-05, dated February 15, 2024 (Transport Canada Emergency AD CF-
2024-05) (referred to after this as the MCAI), issued by Transport 
Canada, which is the aviation authority for Canada, to correct an 
unsafe condition on P&WC Model PT6A-64, PT6A-66, PT6A-66A, PT6A-66B, 
PT6A-66D, PT6A-66T, PT6A-67, PT6A-67A, PT6A-67AF, PT6A-67AG, PT6A-67B, 
PT6A-67D, PT6A-67F, PT6A-67P, PT6A-67R, PT6A-67RM, PT6A-67T, PT6A-68, 
PT6A-68B, PT6A-68C, PT6A-68D, PT6A-68T, PT6E-67XP, and PT6E-66XT 
engines. The MCAI states that there has been a recent in-service report 
of a PT2 blade failure on a model PT6A-67 engine and two reports of PT2 
blade failures during testing at the manufacturer's facility. The PT2 
blade failures were contained. The manufacturer is investigating the 
root cause of the PT2 blade failures, but the preliminary investigation 
determined that the affected power turbine modules contained PT2 blades 
with part number 3056693-01, which were newly manufactured from the 
same raw material. In all cases, the PT2 blades had accumulated less 
than 25 hours air time since new. Transport Canada Emergency AD CF-
2024-05 specifies removal of the suspect blades prior to the next 
flight and prohibits installation of the suspect blades. Transport 
Canada Emergency AD CF-2024-05 states that the corrective actions are 
interim actions until the root cause investigation is completed. This 
condition, if not addressed, could result in engine power loss or 
engine in-flight shut down, resulting in consequent emergency landing 
or reduced control of the airplane. 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-2024-0458.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Transport Canada Emergency AD CF-2024-05, which 
requires replacing the affected PT2 blades. Transport Canada Emergency 
AD CF-2024-05 also prohibits the installation of the affected PT2 
blades. 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 ADDRESSES.

FAA's Determination

    This product has been approved by the aviation authority of another 
country and is 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 and 
service information described above. The FAA is issuing this AD after 
determining that the unsafe condition described previously is likely to 
exist or develop in other products of the same type design.

AD Requirements

    This AD requires accomplishing the actions specified in the MCAI, 
except as discussed under ``Differences Between this AD and the MCAI.''

Differences Between This AD and the MCAI

    The MCAI applies to P&WC Model PT6A-66T, PT6A-68B, PT6A-68C, and 
PT6A-68T engines, but this emergency AD does not as these engines are 
not U.S. type-certificated.

Interim Action

    The FAA considers that this AD is an interim action. The 
manufacturer is currently investigating the root cause of the unsafe 
condition identified in this AD. If final action is later identified, 
the FAA might consider further rulemaking.

Justification for Immediate Adoption and Determination of the Effective 
Date

    Section 553(b)(3)(B) of the Administrative Procedure Act (APA) (5 
U.S.C. 551 et seq.) authorizes agencies to dispense with notice and 
comment procedures for rules when the agency, for ``good cause,'' finds 
that those procedures are ``impracticable, unnecessary, or contrary to 
the public interest.'' Under this section, an agency, upon finding good 
cause, may issue a final rule without providing notice and seeking 
comment prior to issuance.

[[Page 18352]]

Further, section 553(d) of the APA authorizes agencies to make rules 
effective in less than thirty days, upon a finding of good cause.
    An unsafe condition exists that required the immediate adoption of 
Emergency AD 2024-04-51, issued on February 16, 2024, to all known U.S. 
owners and operators of these engines. The FAA found that the risk to 
the flying public justified waiving notice and comment prior to 
adoption of this rule because failure of the PT2 blade could result in 
engine power loss or engine in-flight shut down, and consequent 
emergency landing or reduced control of the airplane. Given the 
significance of the risk presented by this unsafe condition, it must be 
immediately addressed. Thus, the FAA has determined that the affected 
PT2 blades must be removed before further flight. These conditions 
still exist, therefore, notice and opportunity for prior public comment 
are impracticable and contrary to the public interest pursuant to 5 
U.S.C. 553(b)(3)(B).
    In addition, the FAA finds that good cause exists pursuant to 5 
U.S.C. 553(d) for making this amendment effective in less than 30 days, 
for the same reasons the FAA found good cause to forego notice and 
comment.

Regulatory Flexibility Act

    The requirements of the Regulatory Flexibility Act (RFA) do not 
apply when an agency finds good cause pursuant to 5 U.S.C. 553 to adopt 
a rule without prior notice and comment. Because FAA has determined 
that it has good cause to adopt this rule without prior notice and 
comment, RFA analysis is not required.

Costs of Compliance

    The FAA estimates that this AD affects 75 engines installed on 
aircraft of U.S. registry. The FAA does not know how many affected PT2 
blades are installed on each engine. This cost estimate therefore 
reflects the cost of replacing one affected PT2 blade per engine. 
Replacing more than one affected PT2 blade at the same time would not 
incur additional labor costs.
    The FAA estimates the following costs to comply with this AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                    Parts cost
                Action                         Labor cost         (average  pro-     Cost per      Cost on U.S.
                                                                    rated cost)       product        operators
----------------------------------------------------------------------------------------------------------------
Replace PT2 blade.....................  8 work-hours x $85 per            $4,001          $4,681        $351,075
                                         hour = $680.
----------------------------------------------------------------------------------------------------------------

    The FAA has included all known costs in its cost estimate. 
According to the manufacturer, however, all 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, and
    (2) Will not affect intrastate aviation in Alaska.

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.


Sec.  39.13   [Amended]

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

2024-04-51 Pratt & Whitney Canada Corp.: Amendment 39-22694; Docket 
No. FAA-2024-0458; Project Identifier MCAI-2024-00116-E.

(a) Effective Date

    The FAA issued emergency Airworthiness Directive (AD) 2024-04-51 
on February 16, 2024, directly to affected owners and operators. As 
a result of such actual notice, the emergency AD was effective for 
those owners and operators on the date it was received. This AD 
contains the same requirements as the emergency AD and, for those 
who did not receive actual notice, is effective on March 28, 2024.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Pratt & Whitney Canada Corp. Model PT6A-64, 
PT6A-66, PT6A-66A, PT6A-66B, PT6A-66D, PT6A-67, PT6A-67A, PT6A-67AF, 
PT6A-67AG, PT6A-67B, PT6A-67D, PT6A-67F, PT6A-67P, PT6A-67R, PT6A-
67RM, PT6A-67T, PT6A-68, PT6A-68D, PT6E-67XP, and PT6E-66XT engines.

(d) Subject

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

(e) Unsafe Condition

    This AD was prompted by reports from the manufacturer of the 
failure of second-stage power turbine (PT2) blades. The FAA is 
issuing this AD to prevent the failure of PT2 blades. The unsafe 
condition, if not addressed, could result in engine power loss or 
engine in-flight shut down, resulting in consequent emergency 
landing or reduced control of the airplane.

(f) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

(g) Required Actions

    Except as specified in paragraph (h) of this AD: Comply with all 
required actions and compliance times specified in, and in

[[Page 18353]]

accordance with, Transport Canada Emergency AD CF-2024-05, dated 
February 15, 2024 (Transport Canada Emergency AD CF-2024-05).

(h) Exceptions to Transport Canada Emergency AD CF-2024-05

    (1) Where Transport Canada Emergency AD CF-2024-05 refers to its 
effective date, this AD requires using the effective date of this 
AD.
    (2) Where Transport Canada Emergency AD CF-2024-05 refers to 
hours air time, this AD requires using flight hours.
    (3) Where paragraph B of Transport Canada Emergency AD CF-2024-
05 specifies ``After the effective date of this AD,'' replace that 
text with ``As of the effective date of this AD.''

(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 
responsible Flight Standards 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 it 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.

(j) Additional Information

    For more information about this AD, contact Barbara Caufield, 
Aviation Safety Engineer, FAA, 2200 South 216th Street, Des Moines, 
WA 98198; phone: (781) 238-7146; email: [email protected].

(k) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference of the service information listed in this 
paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this service information as applicable to do 
the actions required by this AD, unless the AD specifies otherwise.
    (i) Transport Canada Emergency AD CF-2024-05, dated February 15, 
2024.
    (ii) [Reserved]
    (3) For Transport Canada Emergency AD CF-2024-05, contact 
Transport Canada, Transport Canada National Aircraft Certification, 
159 Cleopatra Drive, Nepean, Ontario K1A 0N5, Canada; phone: (888) 
663-3639; email: [email protected]; website: tc.canada.ca/en/
aviation.
    (4) You may view this service information at FAA, Airworthiness 
Products Section, Operational Safety Branch, 2200 South 216th 
Street, Des Moines, WA. 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: [email protected].

    Issued on February 29, 2024.
Victor Wicklund,
Deputy Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2024-05238 Filed 3-8-24; 11:15 am]
BILLING CODE 4910-13-P