Airworthiness Directives; Pratt & Whitney Canada Corp. Turboprop Engines, 49981-49983 [2020-17783]

Download as PDF Federal Register / Vol. 85, No. 159 / Monday, August 17, 2020 / Proposed Rules modification, or alteration required by this AD if it is approved by The Boeing Company Organization Designation Authorization (ODA) that has been authorized by the Manager, Los Angeles ACO Branch, FAA, to make those findings. To be approved, the repair method, modification deviation, or alteration deviation must meet the certification basis of the airplane, and the approval must specifically refer to this AD. (4) AMOCs approved previously for AD 2013–18–08 are approved as AMOCs for the corresponding provisions of Boeing Alert Service Bulletin 737–53A1346, dated March 27, 2020, that are required by paragraph (g) of this AD. (5) For service information that contains steps that are labeled as Required for Compliance (RC), the provisions of paragraphs (j)(5)(i) and (ii) of this AD apply. (i) The steps labeled as RC, including substeps under an RC step and any figures identified in an RC step, must be done to comply with the AD. If a step or substep is labeled ‘‘RC Exempt,’’ then the RC requirement is removed from that step or substep. An AMOC is required for any deviations to RC steps, including substeps and identified figures. (ii) Steps not labeled as RC may be deviated from using accepted methods in accordance with the operator’s maintenance or inspection program without obtaining approval of an AMOC, provided the RC steps, including substeps and identified figures, can still be done as specified, and the airplane can be put back in an airworthy condition. DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA–2020–0692; Project Identifier MCAI–2019–00140–E] RIN 2120–AA64 Airworthiness Directives; Pratt & Whitney Canada Corp. Turboprop Engines Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed rulemaking (NPRM). AGENCY: The FAA proposes to adopt a new airworthiness directive (AD) for all Pratt & Whitney Canada Corp. PT6A–34, –34B, –34AG, –114, and –114A model turboprop engines. This proposed AD was prompted by several reports of lowtime fractures of compressor turbine (CT) blades resulting in loss of power or in-flight shutdown of the engine. This proposed AD would require replacement of certain CT vanes. This proposed AD would also require removal from service of certain CT blades when these blades have been operated with certain CT vanes. The FAA is proposing this AD to address the unsafe condition on these products. DATES: The FAA must receive comments on this proposed AD by October 1, 2020. (k) Related Information ADDRESSES: You may send comments, (1) For more information about this AD, using the procedures found in 14 CFR contact James Guo, Aerospace Engineer, 11.43 and 11.45, by any of the following Airframe Section, FAA, Los Angeles ACO methods: Branch, 3960 Paramount Boulevard, • Federal eRulemaking Portal: Go to Lakewood, CA 90712–4137; phone: 562–627– https://www.regulations.gov. Follow the 5357; fax: 562–627–5210; email: james.guo@ instructions for submitting comments. faa.gov. • Fax: 202–493–2251. (2) For service information identified in • Mail: U.S. Department of this AD, contact Boeing Commercial Transportation, Docket Operations, M– Airplanes, Attention: Contractual & Data 30, West Building Ground Floor, Room Services (C&DS), 2600 Westminster Blvd., W12 140, 1200 New Jersey Avenue SE, MC 110–SK57, Seal Beach, CA 90740–5600; Washington, DC 20590. telephone 562–797–1717; internet https:// • Hand Delivery: Deliver to Mail www.myboeingfleet.com. You may view this address above between 9 a.m. and 5 referenced service information at the FAA, p.m., Monday through Friday, except Airworthiness Products Section, Operational Federal holidays. Safety Branch, 2200 South 216th St., Des Moines, WA. For information on the availability of this material at the FAA, call 206–231–3195. Issued on August 6, 2020. Lance T. Gant, Director, Compliance & Airworthiness Division, Aircraft Certification Service. [FR Doc. 2020–17837 Filed 8–14–20; 8:45 am] BILLING CODE 4910–13–P VerDate Sep<11>2014 16:51 Aug 14, 2020 Jkt 250001 SUMMARY: Examining the AD Docket You may examine the AD docket on the internet at https:// www.regulations.gov by searching for and locating Docket No. FAA–2020– 0692; 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 PO 00000 Frm 00004 Fmt 4702 Sfmt 4702 49981 listed above. Comments will be available in the AD docket shortly after receipt. FOR FURTHER INFORMATION CONTACT: Barbara Caufield, Aerospace Engineer, ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803; phone: 781–238–7146; fax: 781–238–7199; email: barbara.caufield@faa.gov. SUPPLEMENTARY INFORMATION: Comments Invited The FAA invites you to send any written relevant data, views, or arguments about this proposal. Send your comments to an address listed under the ADDRESSES section. Include ‘‘Docket No. FAA–2020–0692; Project Identifier MCAI–2019–00140–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 NPRM 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 https:// www.regulations.gov, including any personal information you provide. The agency will also post a report summarizing each substantive verbal contact we received about this proposal. Confidential Business Information 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, Aerospace Engineer, ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803. Any commentary that the FAA receives which is not specifically designated as CBI will be placed in the public docket for this rulemaking. E:\FR\FM\17AUP1.SGM 17AUP1 49982 Federal Register / Vol. 85, No. 159 / Monday, August 17, 2020 / Proposed Rules Background Transport Canada, which is the aviation authority for Canada, has issued Canada AD CF 2019–30R1, dated December 17, 2019 (referred to after this as ‘‘the MCAI’’), to address the unsafe condition on these products. The MCAI states: There have been several reported events of low time CT blade fractures resulting in power loss/In-flight shutdown (IFSD) on post P&WC Service Bulletin (SB) 1669 configured PT6A–114 engines, featuring new CMSX–6 CT blades. In addition, relatively low time failures of Non-P&WC CT blades have also been reported on PT6A–34 and –114 series engines. In service data shows that these low time failures were reported on engines that had CT vanes installed that were repaired in accordance with repair specification number STI 72–50–254 held by Southwest Turbine Inc. (STI). Most of the affected engines are installed on single-engine powered aeroplanes and some events have resulted in the loss of the aeroplane and fatalities. Dimensional checks and operational testing of the subject STI repaired CT vane removed from an incident engine, revealed that it did not conform to the engine manufacturer’s CT vane type design criteria. The noted variations and features in the STI repaired CT vane can cause airflow distortion and subsequent aerofoil excitation of the CT blades resulting in High Cycle Fatigue (HCF) failure of the CT blades. Test data indicates that the stress levels induced in CT blades by the adverse effect of subject airflow distortion exceeds the design requirements for CMSX– 6 CT blades. An IFSD or loss of power on a singleengine powered aeroplane under certain conditions can lead to an unsafe condition as seen in some past events. AD CF–2019–30 was issued on 19 August 2019 to address the potential hazard of power loss/IFSD as a result of CT blade failures on engines with CT vanes installed that were repaired in accordance with repair specification number STI 72–50–254. This AD revision, CF–2019–30R1, is issued to update the background information and to clarify the affected P&WC CT blade Part Numbers (P/Ns). You may obtain further information by examining the MCAI in the AD docket on the internet at https:// www.regulations.gov by searching for and locating Docket No. FAA–2020– 0692. FAA’s Determination This product has been approved by the aviation authority of Canada and is approved for operation in the United States. Pursuant to our bilateral agreement with Canada, they have notified us of the unsafe condition described in the MCAI and service information referenced above. The FAA is issuing this NPRM because we evaluated all the relevant information provided by Transport Canada and determined the unsafe condition described previously is likely to exist or develop in other products of the same type design. Proposed AD Requirements This proposed AD would require replacement of certain CT vanes. This proposed AD would also require removal from service of certain CT blades when these blades have been operated with certain CT vanes. Costs of Compliance The FAA estimates that this proposed AD affects 907 engines installed on airplanes of U.S. registry. The FAA estimates that 63 engines will need to replace the CT vanes and CT blades. The FAA estimates the following costs to comply with this proposed AD: ESTIMATED COSTS Action Labor cost Remove and replace certain CT vanes .......... Remove and replace CMSX–6 CT blade set 16 work-hours × $85 per hour = $1,360 ........ 16 work-hours × $85 per hour = $1,360 ........ 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. Parts cost 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 regulation: (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 Proposed Amendment The FAA determined that this proposed AD would not have federalism Accordingly, under the authority delegated to me by the Administrator, 16:51 Aug 14, 2020 Jkt 250001 PO 00000 Frm 00005 Fmt 4702 Sfmt 4702 Cost on U.S. operators $117,149 91,631 $7,380,387 5,772,753 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. § 39.13 [Amended] 2. The FAA amends § 39.13 by adding the following new airworthiness directive (AD): ■ Pratt & Whitney Canada Corp.: Docket No. FAA–2020–0692; Project Identifier MCAI–2019–00140–E. (a) Comments Due Date The FAA must receive comments by October 1, 2020. (b) Affected ADs None. (c) Applicability Regulatory Findings VerDate Sep<11>2014 $115,789 90,271 Cost per product This AD applies to all Pratt & Whitney Canada Corp. PT6A–34, –34B, –34AG, –114, and –114A model turboprop engines. E:\FR\FM\17AUP1.SGM 17AUP1 Federal Register / Vol. 85, No. 159 / Monday, August 17, 2020 / Proposed Rules (d) Subject Issued on August 10, 2020. Lance T. Gant, Director, Compliance & Airworthiness Division, Aircraft Certification Service. Joint Aircraft System Component (JASC) Code 7250, Turbine Section. (e) Unsafe Condition This AD was prompted by several reports of low-time fractures of compressor turbine (CT) blades resulting in loss of power or inflight shutdown of the engine. The FAA is issuing this AD to prevent failure of the CT blade. The unsafe condition, if not addressed, could result in failure of the engine, in-flight shutdown, and loss of the airplane. (f) Compliance (1) Within 250 flight hours (FHs) or 270 days after the effective date of this AD, whichever occurs first: (i) Remove from service any CT vane repaired in accordance with Southwest Turbine Inc. (STI) repair specification STI– 72–50–254 and replace with a non-STIrepaired CT vane. (ii) Remove from service any CMSX–6 CT blade that has been operated on an affected engine with a CT vane repaired in accordance with STI repair specification STI–72–50–254. (2) [Reserved] (h) Installation Prohibition After the effective date of this AD, do not install on any engine a CT vane that was repaired in accordance with repair specification STI–72–50–254. (i) Alternative Methods of Compliance (AMOCs) (1) The Manager, ECO 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 ECO Branch, send it to the attention of the person identified in paragraph (j)(1) of this AD. You may email your request to: ANE-AD-AMOC@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 (1) For more information about this AD, contact Barbara Caufield, Aerospace Engineer, ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803; phone: 781– 238–7146; fax: 781–238–7199; email: barbara.caufield@faa.gov. (2) Refer to Transport Canada AD CF 2019– 30R1, dated December 17, 2019, for more information. You may examine the Transport Canada AD in the AD docket on the internet at https://www.regulations.gov by searching for and locating it in Docket No. FAA–2020– 0692. Jkt 250001 DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 71 RIN 2120–AA66 (g) Required Actions 16:51 Aug 14, 2020 BILLING CODE 4910–13–P [Docket No. FAA–2020–0741; Airspace Docket No. 19–AWP–79] Comply with this AD within the compliance times specified, unless already done. VerDate Sep<11>2014 [FR Doc. 2020–17783 Filed 8–14–20; 8:45 am] Proposed Amendment of Class D and E Airspace; Fallon, NV Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed rulemaking (NPRM). AGENCY: This action proposes to modify Class E airspace at Fallon NAS (Voorhis Field) Airport, by revoking the Class E airspace designated as an extension to a Class D or Class E surface area. This action also proposes to modify the Class E airspace extending upward from 700 feet above the surface. Further, this action proposes to modify the Class E airspace extending upward from 1,200 feet above the surface. Lastly, this action proposes numerous administrative amendments to the airspaces’ legal descriptions. This action would ensure the safety and management of instrument flight rules (IFR) operations at the airport. DATES: Comments must be received on or before October 1, 2020. ADDRESSES: Send comments on this proposal to the U.S. Department of Transportation, Docket Operations, 1200 New Jersey Avenue SE, West Building Ground Floor, Room W12–140, Washington, DC 20590; telephone: 1– 800–647–5527, or (202) 366–9826. You must identify FAA Docket No. FAA– 2020–0741; Airspace Docket No. 19– AWP–79, at the beginning of your comments. You may also submit comments through the internet at https://www.regulations.gov. FAA Order 7400.11D, Airspace Designations and Reporting Points, and subsequent amendments can be viewed online at https://www.faa.gov/air_ traffic/publications/. For further information, you can contact the Airspace Policy Group, Federal Aviation Administration, 800 Independence Avenue SW, Washington, DC 20591; telephone: (202) 267–8783. The Order is also available for inspection at the SUMMARY: PO 00000 Frm 00006 Fmt 4702 Sfmt 4702 49983 National Archives and Records Administration (NARA). For information on the availability of FAA Order 7400.11D at NARA, email fedreg.legal@nara.gov or go to https:// www.archives.gov/federal-register/cfr/ ibr-locations.html. FOR FURTHER INFORMATION CONTACT: Matthew Van Der Wal, Federal Aviation Administration, Western Service Center, Operations Support Group, 2200 S 216th Street, Des Moines, WA 98198; telephone (206) 231–3695. SUPPLEMENTARY INFORMATION: Authority for This Rulemaking The FAA’s authority to issue rules regarding aviation safety is found in Title 49 of the United States Code. 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. This rulemaking is promulgated under the authority described in Subtitle VII, Part A, Subpart I, Section 40103. Under that section, the FAA is charged with prescribing regulations to assign the use of airspace necessary to ensure the safety of aircraft and the efficient use of airspace. This regulation is within the scope of that authority, as it would amend the Class D and Class E airspace at Fallon NAS (Voorhis Field) Airport, Fallon, NV, to support IFR operations at the airport. Comments Invited Interested parties are invited to participate in this proposed rulemaking by submitting such written data, views, or arguments, as they may desire. Comments that provide the factual basis supporting the views and suggestions presented are particularly helpful in developing reasoned regulatory decisions on the proposal. Comments are specifically invited on the overall regulatory, aeronautical, economic, environmental, and energy-related aspects of the proposal. Communications should identify both docket numbers and be submitted in triplicate to the address listed above. Persons wishing the FAA to acknowledge receipt of their comments on this notice must submit with those comments a self-addressed, stamped postcard on which the following statement is made: ‘‘Comments to Docket No. FAA–2020–0741; Airspace Docket No. 19–AWP–79’’. The postcard will be date/time stamped and returned to the commenter. All communications received before the specified closing date for comments will be considered before taking action E:\FR\FM\17AUP1.SGM 17AUP1

Agencies

[Federal Register Volume 85, Number 159 (Monday, August 17, 2020)]
[Proposed Rules]
[Pages 49981-49983]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-17783]


-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2020-0692; Project Identifier MCAI-2019-00140-E]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney Canada Corp. Turboprop 
Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for all Pratt & Whitney Canada Corp. PT6A-34, -34B, -34AG, -114, and -
114A model turboprop engines. This proposed AD was prompted by several 
reports of low-time fractures of compressor turbine (CT) blades 
resulting in loss of power or in-flight shutdown of the engine. This 
proposed AD would require replacement of certain CT vanes. This 
proposed AD would also require removal from service of certain CT 
blades when these blades have been operated with certain CT vanes. The 
FAA is proposing this AD to address the unsafe condition on these 
products.

DATES: The FAA must receive comments on this proposed AD by October 1, 
2020.

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 https://www.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.

Examining the AD Docket

    You may examine the AD docket on the internet at https://www.regulations.gov by searching for and locating Docket No. FAA-2020-
0692; 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. Comments will be available in the AD 
docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Barbara Caufield, Aerospace Engineer, 
ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803; phone: 
781-238-7146; fax: 781-238-7199; email: [email protected].

SUPPLEMENTARY INFORMATION: 

Comments Invited

    The FAA invites you to send any written relevant data, views, or 
arguments about this proposal. Send your comments to an address listed 
under the ADDRESSES section. Include ``Docket No. FAA-2020-0692; 
Project Identifier MCAI-2019-00140-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 NPRM 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 
https://www.regulations.gov, including any personal information you 
provide. The agency will also post a report summarizing each 
substantive verbal contact we received about this proposal.

Confidential Business Information

    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, Aerospace Engineer, ECO Branch, 
FAA, 1200 District Avenue, Burlington, MA 01803. Any commentary that 
the FAA receives which is not specifically designated as CBI will be 
placed in the public docket for this rulemaking.

[[Page 49982]]

Background

    Transport Canada, which is the aviation authority for Canada, has 
issued Canada AD CF 2019-30R1, dated December 17, 2019 (referred to 
after this as ``the MCAI''), to address the unsafe condition on these 
products. The MCAI states:

    There have been several reported events of low time CT blade 
fractures resulting in power loss/In-flight shutdown (IFSD) on post 
P&WC Service Bulletin (SB) 1669 configured PT6A-114 engines, 
featuring new CMSX-6 CT blades. In addition, relatively low time 
failures of Non-P&WC CT blades have also been reported on PT6A-34 
and -114 series engines.
    In service data shows that these low time failures were reported 
on engines that had CT vanes installed that were repaired in 
accordance with repair specification number STI 72-50-254 held by 
Southwest Turbine Inc. (STI). Most of the affected engines are 
installed on single-engine powered aeroplanes and some events have 
resulted in the loss of the aeroplane and fatalities.
    Dimensional checks and operational testing of the subject STI 
repaired CT vane removed from an incident engine, revealed that it 
did not conform to the engine manufacturer's CT vane type design 
criteria. The noted variations and features in the STI repaired CT 
vane can cause airflow distortion and subsequent aerofoil excitation 
of the CT blades resulting in High Cycle Fatigue (HCF) failure of 
the CT blades. Test data indicates that the stress levels induced in 
CT blades by the adverse effect of subject airflow distortion 
exceeds the design requirements for CMSX-6 CT blades.
    An IFSD or loss of power on a single-engine powered aeroplane 
under certain conditions can lead to an unsafe condition as seen in 
some past events. AD CF-2019-30 was issued on 19 August 2019 to 
address the potential hazard of power loss/IFSD as a result of CT 
blade failures on engines with CT vanes installed that were repaired 
in accordance with repair specification number STI 72-50-254.
    This AD revision, CF-2019-30R1, is issued to update the 
background information and to clarify the affected P&WC CT blade 
Part Numbers (P/Ns).

    You may obtain further information by examining the MCAI in the AD 
docket on the internet at https://www.regulations.gov by searching for 
and locating Docket No. FAA-2020-0692.

FAA's Determination

    This product has been approved by the aviation authority of Canada 
and is approved for operation in the United States. Pursuant to our 
bilateral agreement with Canada, they have notified us of the unsafe 
condition described in the MCAI and service information referenced 
above. The FAA is issuing this NPRM because we evaluated all the 
relevant information provided by Transport Canada and determined the 
unsafe condition described previously is likely to exist or develop in 
other products of the same type design.

Proposed AD Requirements

    This proposed AD would require replacement of certain CT vanes. 
This proposed AD would also require removal from service of certain CT 
blades when these blades have been operated with certain CT vanes.

Costs of Compliance

    The FAA estimates that this proposed AD affects 907 engines 
installed on airplanes of U.S. registry. The FAA estimates that 63 
engines will need to replace the CT vanes and CT blades.
    The FAA estimates the following costs to comply with this proposed 
AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                     Cost per      Cost on U.S.
                Action                         Labor cost           Parts cost        product        operators
----------------------------------------------------------------------------------------------------------------
Remove and replace certain CT vanes...  16 work-hours x $85 per         $115,789        $117,149      $7,380,387
                                         hour = $1,360.
Remove and replace CMSX-6 CT blade set  16 work-hours x $85 per           90,271          91,631       5,772,753
                                         hour = $1,360.
----------------------------------------------------------------------------------------------------------------

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

    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 
regulation:
    (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 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

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 (AD):

Pratt & Whitney Canada Corp.: Docket No. FAA-2020-0692; Project 
Identifier MCAI-2019-00140-E.

(a) Comments Due Date

    The FAA must receive comments by October 1, 2020.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to all Pratt & Whitney Canada Corp. PT6A-34, -
34B, -34AG, -114, and -114A model turboprop engines.

[[Page 49983]]

(d) Subject

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

(e) Unsafe Condition

    This AD was prompted by several reports of low-time fractures of 
compressor turbine (CT) blades resulting in loss of power or in-
flight shutdown of the engine. The FAA is issuing this AD to prevent 
failure of the CT blade. The unsafe condition, if not addressed, 
could result in failure of the engine, in-flight shutdown, and loss 
of the airplane.

(f) Compliance

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

(g) Required Actions

    (1) Within 250 flight hours (FHs) or 270 days after the 
effective date of this AD, whichever occurs first:
    (i) Remove from service any CT vane repaired in accordance with 
Southwest Turbine Inc. (STI) repair specification STI-72-50-254 and 
replace with a non-STI-repaired CT vane.
    (ii) Remove from service any CMSX-6 CT blade that has been 
operated on an affected engine with a CT vane repaired in accordance 
with STI repair specification STI-72-50-254.
    (2) [Reserved]

(h) Installation Prohibition

    After the effective date of this AD, do not install on any 
engine a CT vane that was repaired in accordance with repair 
specification STI-72-50-254.

(i) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, ECO 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 
ECO Branch, send it to the attention of the person identified in 
paragraph (j)(1) of this AD. You may email your request 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) Related Information

    (1) For more information about this AD, contact Barbara 
Caufield, Aerospace Engineer, ECO Branch, FAA, 1200 District Avenue, 
Burlington, MA 01803; phone: 781-238-7146; fax: 781-238-7199; email: 
[email protected].
    (2) Refer to Transport Canada AD CF 2019-30R1, dated December 
17, 2019, for more information. You may examine the Transport Canada 
AD in the AD docket on the internet at https://www.regulations.gov 
by searching for and locating it in Docket No. FAA-2020-0692.

    Issued on August 10, 2020.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2020-17783 Filed 8-14-20; 8:45 am]
BILLING CODE 4910-13-P
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