Airworthiness Directives; Pratt & Whitney Division Turbofan Engines, 62717-62719 [2021-24574]

Download as PDF Federal Register / Vol. 86, No. 216 / Friday, November 12, 2021 / Rules and Regulations (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. DEPARTMENT OF TRANSPORTATION (j) Related Information [Docket No. FAA–2021–0577; Project Identifier AD–2021–00470–E; Amendment 39–21787; AD 2021–22–14] (1) For more information about this AD, contact Andrea Jimenez, Aerospace Engineer, COS Program Management Section, Operational Safety Branch, Compliance & Airworthiness Division, FAA, 1600 Stewart Ave., Suite 410, Westbury, NY 11590; telephone (516) 228–7330; email andrea.jimenez@faa.gov. (2) Guimbal Service Bulletin SB 16–021 D, dated May 20, 2019, which is not incorporated by reference, contains additional information about the subject of this AD. This service information is available at the contact information specified in paragraphs (k)(3) and (4) of this AD. (3) The subject of this AD is addressed in European Union Aviation Safety Agency (EASA) AD 2019–0187, dated July 31, 2019. You may view the EASA AD at https:// www.regulations.gov in Docket No. FAA– 2021–0620. (k) Material Incorporated by Reference lotter on DSK11XQN23PROD with RULES1 (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) Guimbal Service Bulletin SB 16–021 E, dated August 27, 2019. (ii) [Reserved] (3) For service information identified in this AD, contact He´licopte`res Guimbal, Basile Ginel, 1070, rue du Lieutenant Parayre, Ae´rodrome d’Aix-en-Provence, 13290 Les Milles, France; telephone 33–04–42–39–10– 88; email basile.ginel@guimbal.com; web https://www.guimbal.com. (4) You may view this service information at the FAA, Office of the Regional Counsel, Southwest Region, 10101 Hillwood Pkwy., Room 6N–321, Fort Worth, TX 76177. For information on the availability of this material at the FAA, call (817) 222–5110. (5) You may view this service information that is incorporated by reference at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, email: fr.inspection@nara.gov, or go to: https://www.archives.gov/federal-register/cfr/ ibr-locations.html. Issued on November 4, 2021. Ross Landes, Deputy Director for Regulatory Operations, Compliance & Airworthiness Division, Aircraft Certification Service. [FR Doc. 2021–24541 Filed 11–10–21; 8:45 am] BILLING CODE 4910–13–P VerDate Sep<11>2014 15:55 Nov 10, 2021 Jkt 256001 Federal Aviation Administration 14 CFR Part 39 Airworthiness Directives; Pratt & Whitney Division Turbofan Engines Federal Aviation Administration (FAA), DOT. ACTION: Final rule. AGENCY: The FAA is superseding Airworthiness Directive (AD) 2021–05– 16 for certain Pratt & Whitney Division (PW) PW4164, PW4164–1D, PW4168, PW4168–1D, PW4168A, PW4168A–1D, and PW4170 model turbofan engines. AD 2021–05–16 required initial and repetitive replacements of the lowpressure turbine (LPT) 4th-stage air sealing ring segment assemblies with parts eligible for installation. AD 2021– 05–16 also required initial and repetitive dimensional inspections of the LPT case for bulging and, depending on the results of the dimensional inspections, repair or replacement of the LPT case. This AD was prompted by notification to the FAA of an inadvertent omission in the LPT 4thstage air sealing ring segment assembly part numbers. This AD requires initial and repetitive replacements of the LPT 4th-stage air sealing ring segment assemblies with parts eligible for installation. This AD also requires initial and repetitive dimensional inspections of the LPT case for bulging and, depending on the results of the dimensional inspections, repair or replacement of the LPT case. The FAA is issuing this AD to address the unsafe condition on these products. DATES: This AD is effective December 17, 2021. The Director of the Federal Register approved the incorporation by reference of a certain other publication listed in this AD as of May 7, 2021 (86 FR 17287, April 2, 2021). ADDRESSES: For service information identified in this final rule, contact Pratt & Whitney Division, 400 Main Street, East Hartford, CT 06118; phone: (800) 565–0140; email: help24@pw.utc.com; website: https://fleetcare. prattwhitney.com. You may view this service information at the Airworthiness Products Section, Operational Safety Branch, FAA, 1200 District Avenue, Burlington, MA 01803. For information on the availability of this material at the SUMMARY: Frm 00005 Fmt 4700 FAA, call (781) 238–7759. It is also available at https://www.regulations.gov by searching for and locating Docket No. FAA–2021–0577. Examining the AD Docket RIN 2120–AA64 PO 00000 62717 Sfmt 4700 You may examine the AD docket at https://www.regulations.gov by searching for and locating Docket No. FAA–2021–0577; 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, ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803; phone: (781) 238–7655; fax: (781) 238–7199; email: carol.nguyen@faa.gov. SUPPLEMENTARY INFORMATION: Background The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to supersede AD 2021–05–16, Amendment 39–21459 (86 FR 17287, April 2, 2021), (AD 2021–05–16). AD 2021–05–16 applied to certain PW PW4164, PW4164–1D, PW4168, PW4168–1D, PW4168A, PW4168A–1D, and PW4170 model turbofan engines with LPT 4th-stage air sealing ring segment assemblies, part number (P/N) 50N463–01 or P/N 50N526–01, installed. The NPRM published in the Federal Register on July 23, 2021 (86 FR 38941). The NPRM was prompted by notification from a manufacturer of parts manufacturer approval (PMA) parts that AD 2021–05–16 should include affected PMA part numbers because the unsafe condition also applies to those parts. AD 2021–05–16 resulted from six reports from the manufacturer concerning LPT 4th-stage vane cluster assemblies leaning back and notching into rotating LPT 4th-stage blades, causing some blades to fracture and release. These incidents resulted in an aborted takeoff, air turnbacks, engine surges, high vibrations, and unplanned engine removals. The incidents were attributed to the LPT 4th-stage air sealing ring segment assemblies moving into the LPT 4th-stage blades knife edge seals, resulting in damage to the ring segment assemblies. In the NPRM, the FAA proposed to require initial and repetitive replacements of the LPT 4thstage air sealing ring segment assemblies with parts eligible for installation. In the E:\FR\FM\12NOR1.SGM 12NOR1 62718 Federal Register / Vol. 86, No. 216 / Friday, November 12, 2021 / Rules and Regulations NPRM, the FAA also proposed to require initial and repetitive dimensional inspections of the LPT case for bulging and, depending on the results of the dimensional inspections, repair or replacement of the LPT case. determined that air safety requires adopting the AD as proposed. Accordingly, the FAA is issuing this AD to address the unsafe condition on these products. This AD is adopted as proposed in the NPRM. Discussion of Final Airworthiness Directive Related Service Information Under 1 CFR Part 51 Comments The FAA received comments from one commenter, the Air Line Pilots Association (ALPA). ALPA supported the NPRM without change. The FAA reviewed Pratt & Whitney Alert Service Bulletin No. PW4G–100– A72–262, Revision No. 1, dated September 3, 2020 (the ASB). The ASB specifies procedures for replacing the LPT 4th-stage air sealing ring segment assemblies and inspecting the LPT case for bulging. The Director of the Federal Register approved the ASB for Conclusion The FAA reviewed the relevant data, considered the comments received, and incorporation by reference as of May 7, 2021 (86 FR 17287, April 2, 2021). 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 99 engines installed on airplanes of U.S. registry. The FAA estimates the following costs to comply with this AD: ESTIMATED COSTS Cost per product Labor cost Inspect the LPT case for bulging. Replace the LPT 4th-stage air sealing ring segment assemblies. 2 work-hours × $85 per hour = $170 ..................................... $0 $170 $16,830 50 work-hours × $85 per hour = $4,250 ................................ 64,592 68,842 6,815,358 The FAA estimates the following costs to do any necessary repair or replacement that would be required Parts cost Cost on U.S. operators Action based on the results of the inspection. The agency has no way of determining the number of aircraft that might need these repairs or replacements. ON-CONDITION COSTS Action Labor cost Repair LPT case to restore dimensions ....................... Replace the LPT case .................................................. 250 work-hours × $85 per hour = $21,250 .................. 0 work-hours × $85 per hour = $0 ............................... lotter on DSK11XQN23PROD with RULES1 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. VerDate Sep<11>2014 15:55 Nov 10, 2021 Jkt 256001 Regulatory Findings The FAA has determined that 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. PO 00000 Frm 00006 Fmt 4700 Sfmt 4700 Parts cost $0 1,300,000 Cost per product $21,250 1,300,000 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. § 39.13 [Amended] 2. The FAA amends § 39.13 by: ■ a. Removing Airworthiness Directive 2021–05–16, Amendment 39–21459 (86 FR 17287, April 2, 2021); and ■ b. Adding the following new airworthiness directive: ■ 2021–22–14 Pratt & Whitney Division: Amendment 39–21787; Docket No. FAA–2021–0577; Project Identifier AD– 2021–00470–E. E:\FR\FM\12NOR1.SGM 12NOR1 Federal Register / Vol. 86, No. 216 / Friday, November 12, 2021 / Rules and Regulations (a) Effective Date This airworthiness directive (AD) is effective December 17, 2021. (b) Affected ADs This AD replaces AD 2021–05–16, Amendment 39–21459 (86 FR 17287, April 2, 2021). (c) Applicability This AD applies to Pratt & Whitney Division (PW) PW4164, PW4164–1D, PW4168, PW4168–1D, PW4168A, PW4168A– 1D, and PW4170 model turbofan engines with low-pressure turbine (LPT) 4th-stage air sealing ring segment assemblies, part number (P/N) 50N463–01, P/N 50N526–01, or FAAapproved equivalent part numbers, installed. (d) Subject Joint Aircraft System Component (JASC) Code 7250, Turbine Section. (e) Unsafe Condition This AD was prompted by several reports from the manufacturer concerning LPT 4thstage vane cluster assemblies leaning back and notching into the rotating LPT 4th-stage blades, causing some blades to fracture and release. A manufacturer investigation into those reports determined that the leaning back of the LPT 4th-stage vane cluster assemblies was caused by damage to the LPT 4th-stage air sealing ring segment assemblies. The FAA is issuing this AD to prevent damage to the LPT 4th-stage air sealing ring segment assemblies, the LPT case, and the LPT 4th-stage blades. The unsafe condition, if not addressed, could result in uncontained release of the LPT 4th-stage blades, damage to the engine, and damage to the airplane. lotter on DSK11XQN23PROD with RULES1 (f) Compliance Comply with this AD within the compliance times specified, unless already done. (g) Required Actions (1) For affected engines that have either the Talon IIA outer combustion chamber assembly, P/N 51J100 or P/N 51J382, or the Talon IIB outer combustion chamber assembly, P/N 51J381 or P/N 51J500, installed, at the next engine shop visit after the effective date of this AD, remove from service the LPT 4th-stage air sealing ring segment assemblies, P/N 50N463–01, P/N 50N526–01, or FAA-approved equivalent part numbers, and replace with parts eligible for installation. (2) For affected engines not referenced in paragraph (g)(1) of this AD, at the next LPT overhaul after the effective date of this AD, remove from service the LPT 4th-stage air sealing ring segment assemblies, P/N 50N463–01, P/N 50N526–01, or FAAapproved equivalent part numbers, and replace with parts eligible for installation. (3) For all affected engines, at each LPT overhaul after compliance with the required actions in paragraph (g)(1) or (2) of this AD, remove from service the LPT 4th-stage air sealing ring segment assemblies, P/N 50N526–01 or FAA-approved equivalent part numbers, and replace with parts eligible for installation. VerDate Sep<11>2014 15:55 Nov 10, 2021 Jkt 256001 (4) During each replacement of the LPT 4th-stage air sealing ring segment assemblies required by paragraphs (g)(1) through (3) of this AD, perform a dimensional inspection of the LPT case for bulging in accordance with the Accomplishment Instructions, paragraph 2, of PW Alert Service Bulletin No. PW4G– 100–A72–262 Revision No. 1, dated September 3, 2020 (the ASB). (5) If, during the dimensional inspection of the LPT case required by paragraph (g)(4) of this AD, any LPT case found to be outside the serviceable limits specified in Table 1: Serviceable Limits and Repairs of the ASB, repair or replace the LPT case before further flight. (h) Definitions For the purpose of this AD: (1) An ‘‘engine shop visit’’ is the induction of an engine into the shop for maintenance involving the separation of pairs of major mating engine flanges H through P. The separation of engine flanges solely for the purpose of transportation without subsequent engine maintenance does not constitute an engine shop visit. (2) An ‘‘LPT overhaul’’ is when the LPT rotor is removed from the engine, all four disks are removed from the LPT rotor, and all blades are removed from the disks. (3) ‘‘Parts eligible for installation’’ are LPT 4th-stage air sealing ring segment assemblies, P/N 50N526–01, or FAA-approved equivalent part numbers, with zero flight cycles since new or with a P/N not mentioned in this AD. (i) Credit for Previous Actions You may take credit for the dimensional inspection of the LPT case for bulging required by paragraph (g)(4) of this AD if the inspection was performed before the effective date of this AD using PW ASB PW4G–100– A72–262 Original Issue, dated October 22, 2019. (j) 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 certification office, send it to the attention of the person identified in paragraph (k) of this AD. Information may be emailed to: ANE-ADAMOC@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. (k) Related Information For more information about this AD, contact Carol Nguyen, Aviation Safety Engineer, ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803; phone: (781) 238–7655; fax: (781) 238–7199; email: carol.nguyen@faa.gov. (l) Material Incorporated by Reference (1) The Director of the Federal Register approved the incorporation by reference PO 00000 Frm 00007 Fmt 4700 Sfmt 4700 62719 (IBR) 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. (3) The following service information was approved for IBR on May 7, 2021 (86 FR 17287, April 2, 2021). (i) Pratt & Whitney Alert Service Bulletin No. PW4G–100–A72–262, Revision No. 1, dated September 3, 2020. (ii) [Reserved] (4) For Pratt & Whitney service information identified in this AD, contact Pratt & Whitney, 400 Main Street, East Hartford, CT 06118; phone: (800) 565–0140; email: help24@pw.utc.com; website: https:// fleetcare.prattwhitney.com. (5) You may view this service information at 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 (781) 238–7759. (6) You may view this service information that is incorporated by reference at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, email: fr.inspection@nara.gov, or go to: https://www.archives.gov/federal-register/cfr/ ibr-locations.html. Issued on October 15, 2021. Lance T. Gant, Director, Compliance & Airworthiness Division, Aircraft Certification Service. [FR Doc. 2021–24574 Filed 11–10–21; 8:45 am] BILLING CODE 4910–13–P DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. FAA–2020–1131; Project Identifier MCAI–2020–00613–R; Amendment 39–21816; AD 2021–05–02] RIN 2120–AA64 Airworthiness Directives; Airbus Helicopters Federal Aviation Administration (FAA), Department of Transportation (DOT). ACTION: Final rule; removal; request for comments. AGENCY: The FAA is removing Airworthiness Directive (AD) 2021–05– 02, which applied to all Airbus Helicopters Model AS350B, AS350BA, AS350B1, AS350B2, AS350B3, AS350C, and AS350D helicopters; Model AS355E, AS355F, AS355F1, AS355F2, AS355N, and AS355NP helicopters; and Model EC130B4 and EC130T2 helicopters. AD 2021–05–02 required determining whether the helicopter has SUMMARY: E:\FR\FM\12NOR1.SGM 12NOR1

Agencies

[Federal Register Volume 86, Number 216 (Friday, November 12, 2021)]
[Rules and Regulations]
[Pages 62717-62719]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-24574]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-0577; Project Identifier AD-2021-00470-E; 
Amendment 39-21787; AD 2021-22-14]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney Division Turbofan 
Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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

SUMMARY: The FAA is superseding Airworthiness Directive (AD) 2021-05-16 
for certain Pratt & Whitney Division (PW) PW4164, PW4164-1D, PW4168, 
PW4168-1D, PW4168A, PW4168A-1D, and PW4170 model turbofan engines. AD 
2021-05-16 required initial and repetitive replacements of the low-
pressure turbine (LPT) 4th-stage air sealing ring segment assemblies 
with parts eligible for installation. AD 2021-05-16 also required 
initial and repetitive dimensional inspections of the LPT case for 
bulging and, depending on the results of the dimensional inspections, 
repair or replacement of the LPT case. This AD was prompted by 
notification to the FAA of an inadvertent omission in the LPT 4th-stage 
air sealing ring segment assembly part numbers. This AD requires 
initial and repetitive replacements of the LPT 4th-stage air sealing 
ring segment assemblies with parts eligible for installation. This AD 
also requires initial and repetitive dimensional inspections of the LPT 
case for bulging and, depending on the results of the dimensional 
inspections, repair or replacement of the LPT case. The FAA is issuing 
this AD to address the unsafe condition on these products.

DATES: This AD is effective December 17, 2021.
    The Director of the Federal Register approved the incorporation by 
reference of a certain other publication listed in this AD as of May 7, 
2021 (86 FR 17287, April 2, 2021).

ADDRESSES: For service information identified in this final rule, 
contact Pratt & Whitney Division, 400 Main Street, East Hartford, CT 
06118; phone: (800) 565-0140; email: [email protected]; website: 
https://fleetcare.prattwhitney.com. You may view this service 
information at the Airworthiness Products Section, Operational Safety 
Branch, FAA, 1200 District Avenue, Burlington, MA 01803. For 
information on the availability of this material at the FAA, call (781) 
238-7759. It is also available at https://www.regulations.gov by 
searching for and locating Docket No. FAA-2021-0577.

Examining the AD Docket

    You may examine the AD docket at https://www.regulations.gov by 
searching for and locating Docket No. FAA-2021-0577; 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, ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803; 
phone: (781) 238-7655; fax: (781) 238-7199; email: 
[email protected].

SUPPLEMENTARY INFORMATION:

Background

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 to supersede AD 2021-05-16, Amendment 39-21459 (86 FR 
17287, April 2, 2021), (AD 2021-05-16). AD 2021-05-16 applied to 
certain PW PW4164, PW4164-1D, PW4168, PW4168-1D, PW4168A, PW4168A-1D, 
and PW4170 model turbofan engines with LPT 4th-stage air sealing ring 
segment assemblies, part number (P/N) 50N463-01 or P/N 50N526-01, 
installed. The NPRM published in the Federal Register on July 23, 2021 
(86 FR 38941). The NPRM was prompted by notification from a 
manufacturer of parts manufacturer approval (PMA) parts that AD 2021-
05-16 should include affected PMA part numbers because the unsafe 
condition also applies to those parts. AD 2021-05-16 resulted from six 
reports from the manufacturer concerning LPT 4th-stage vane cluster 
assemblies leaning back and notching into rotating LPT 4th-stage 
blades, causing some blades to fracture and release. These incidents 
resulted in an aborted takeoff, air turnbacks, engine surges, high 
vibrations, and unplanned engine removals. The incidents were 
attributed to the LPT 4th-stage air sealing ring segment assemblies 
moving into the LPT 4th-stage blades knife edge seals, resulting in 
damage to the ring segment assemblies. In the NPRM, the FAA proposed to 
require initial and repetitive replacements of the LPT 4th-stage air 
sealing ring segment assemblies with parts eligible for installation. 
In the

[[Page 62718]]

NPRM, the FAA also proposed to require initial and repetitive 
dimensional inspections of the LPT case for bulging and, depending on 
the results of the dimensional inspections, repair or replacement of 
the LPT case.

Discussion of Final Airworthiness Directive

Comments

    The FAA received comments from one commenter, the Air Line Pilots 
Association (ALPA). ALPA supported the NPRM without change.

Conclusion

    The FAA reviewed the relevant data, considered the comments 
received, and determined that air safety requires adopting the AD as 
proposed. Accordingly, the FAA is issuing this AD to address the unsafe 
condition on these products. This AD is adopted as proposed in the 
NPRM.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Pratt & Whitney Alert Service Bulletin No. PW4G-
100-A72-262, Revision No. 1, dated September 3, 2020 (the ASB). The ASB 
specifies procedures for replacing the LPT 4th-stage air sealing ring 
segment assemblies and inspecting the LPT case for bulging. The 
Director of the Federal Register approved the ASB for incorporation by 
reference as of May 7, 2021 (86 FR 17287, April 2, 2021). 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 99 engines installed on 
airplanes of U.S. registry.
    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
----------------------------------------------------------------------------------------------------------------
Inspect the LPT case for bulging...  2 work-hours x $85 per hour              $0            $170         $16,830
                                      = $170.
Replace the LPT 4th-stage air        50 work-hours x $85 per              64,592          68,842       6,815,358
 sealing ring segment assemblies.     hour = $4,250.
----------------------------------------------------------------------------------------------------------------

    The FAA estimates the following costs to do any necessary repair or 
replacement that would be required based on the results of the 
inspection. The agency has no way of determining the number of aircraft 
that might need these repairs or replacements.

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                     Cost per
                    Action                                 Labor cost               Parts cost        product
----------------------------------------------------------------------------------------------------------------
Repair LPT case to restore dimensions.........  250 work-hours x $85 per hour =               $0         $21,250
                                                 $21,250.
Replace the LPT case..........................  0 work-hours x $85 per hour = $0       1,300,000       1,300,000
----------------------------------------------------------------------------------------------------------------

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 has determined that 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.


Sec.  39.13  [Amended]

0
2. The FAA amends Sec.  39.13 by:
0
a. Removing Airworthiness Directive 2021-05-16, Amendment 39-21459 (86 
FR 17287, April 2, 2021); and
0
b. Adding the following new airworthiness directive:

2021-22-14 Pratt & Whitney Division: Amendment 39-21787; Docket No. 
FAA-2021-0577; Project Identifier AD-2021-00470-E.

[[Page 62719]]

(a) Effective Date

    This airworthiness directive (AD) is effective December 17, 
2021.

(b) Affected ADs

    This AD replaces AD 2021-05-16, Amendment 39-21459 (86 FR 17287, 
April 2, 2021).

(c) Applicability

    This AD applies to Pratt & Whitney Division (PW) PW4164, PW4164-
1D, PW4168, PW4168-1D, PW4168A, PW4168A-1D, and PW4170 model 
turbofan engines with low-pressure turbine (LPT) 4th-stage air 
sealing ring segment assemblies, part number (P/N) 50N463-01, P/N 
50N526-01, or FAA-approved equivalent part numbers, installed.

(d) Subject

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

(e) Unsafe Condition

    This AD was prompted by several reports from the manufacturer 
concerning LPT 4th-stage vane cluster assemblies leaning back and 
notching into the rotating LPT 4th-stage blades, causing some blades 
to fracture and release. A manufacturer investigation into those 
reports determined that the leaning back of the LPT 4th-stage vane 
cluster assemblies was caused by damage to the LPT 4th-stage air 
sealing ring segment assemblies. The FAA is issuing this AD to 
prevent damage to the LPT 4th-stage air sealing ring segment 
assemblies, the LPT case, and the LPT 4th-stage blades. The unsafe 
condition, if not addressed, could result in uncontained release of 
the LPT 4th-stage blades, damage to the engine, and damage to the 
airplane.

(f) Compliance

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

(g) Required Actions

    (1) For affected engines that have either the Talon IIA outer 
combustion chamber assembly, P/N 51J100 or P/N 51J382, or the Talon 
IIB outer combustion chamber assembly, P/N 51J381 or P/N 51J500, 
installed, at the next engine shop visit after the effective date of 
this AD, remove from service the LPT 4th-stage air sealing ring 
segment assemblies, P/N 50N463-01, P/N 50N526-01, or FAA-approved 
equivalent part numbers, and replace with parts eligible for 
installation.
    (2) For affected engines not referenced in paragraph (g)(1) of 
this AD, at the next LPT overhaul after the effective date of this 
AD, remove from service the LPT 4th-stage air sealing ring segment 
assemblies, P/N 50N463-01, P/N 50N526-01, or FAA-approved equivalent 
part numbers, and replace with parts eligible for installation.
    (3) For all affected engines, at each LPT overhaul after 
compliance with the required actions in paragraph (g)(1) or (2) of 
this AD, remove from service the LPT 4th-stage air sealing ring 
segment assemblies, P/N 50N526-01 or FAA-approved equivalent part 
numbers, and replace with parts eligible for installation.
    (4) During each replacement of the LPT 4th-stage air sealing 
ring segment assemblies required by paragraphs (g)(1) through (3) of 
this AD, perform a dimensional inspection of the LPT case for 
bulging in accordance with the Accomplishment Instructions, 
paragraph 2, of PW Alert Service Bulletin No. PW4G-100-A72-262 
Revision No. 1, dated September 3, 2020 (the ASB).
    (5) If, during the dimensional inspection of the LPT case 
required by paragraph (g)(4) of this AD, any LPT case found to be 
outside the serviceable limits specified in Table 1: Serviceable 
Limits and Repairs of the ASB, repair or replace the LPT case before 
further flight.

(h) Definitions

    For the purpose of this AD:
    (1) An ``engine shop visit'' is the induction of an engine into 
the shop for maintenance involving the separation of pairs of major 
mating engine flanges H through P. The separation of engine flanges 
solely for the purpose of transportation without subsequent engine 
maintenance does not constitute an engine shop visit.
    (2) An ``LPT overhaul'' is when the LPT rotor is removed from 
the engine, all four disks are removed from the LPT rotor, and all 
blades are removed from the disks.
    (3) ``Parts eligible for installation'' are LPT 4th-stage air 
sealing ring segment assemblies, P/N 50N526-01, or FAA-approved 
equivalent part numbers, with zero flight cycles since new or with a 
P/N not mentioned in this AD.

(i) Credit for Previous Actions

    You may take credit for the dimensional inspection of the LPT 
case for bulging required by paragraph (g)(4) of this AD if the 
inspection was performed before the effective date of this AD using 
PW ASB PW4G-100-A72-262 Original Issue, dated October 22, 2019.

(j) 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 
certification office, send it to the attention of the person 
identified in paragraph (k) of this AD. Information may be emailed 
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) Related Information

    For more information about this AD, contact Carol Nguyen, 
Aviation Safety Engineer, ECO Branch, FAA, 1200 District Avenue, 
Burlington, MA 01803; phone: (781) 238-7655; fax: (781) 238-7199; 
email: [email protected].

(l) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference (IBR) 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.
    (3) The following service information was approved for IBR on 
May 7, 2021 (86 FR 17287, April 2, 2021).
    (i) Pratt & Whitney Alert Service Bulletin No. PW4G-100-A72-262, 
Revision No. 1, dated September 3, 2020.
    (ii) [Reserved]
    (4) For Pratt & Whitney service information identified in this 
AD, contact Pratt & Whitney, 400 Main Street, East Hartford, CT 
06118; phone: (800) 565-0140; email: [email protected]; website: 
https://fleetcare.prattwhitney.com.
    (5) You may view this service information at 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 (781) 238-7759.
    (6) You may view this service information that is incorporated 
by reference at the National Archives and Records Administration 
(NARA). For information on the availability of this material at 
NARA, email: [email protected], or go to: https://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued on October 15, 2021.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2021-24574 Filed 11-10-21; 8:45 am]
BILLING CODE 4910-13-P

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