[Federal Register Volume 88, Number 79 (Tuesday, April 25, 2023)]
[Rules and Regulations]
[Pages 24897-24899]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-08624]



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 Rules and Regulations
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  Federal Register / Vol. 88, No. 79 / Tuesday, April 25, 2023 / Rules 
and Regulations  

[[Page 24897]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2023-0022; Project Identifier MCAI-2022-00564-E; 
Amendment 39-22400; AD 2023-06-14]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney Canada Corporation 
Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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

SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
certain Pratt & Whitney Canada Corporation (P&WC) PW308A and PW308C 
model turbofan engines. This AD is prompted by a manufacturer's design 
review, which identified that the combustion chamber outer case (CCOC) 
to rear compressor case (RCC) flange bolt low cycle fatigue life was 
inadequate and that those flange bolts may develop cracks resulting in 
flange bolt fracture. This AD requires replacing all CCOC flange bolts 
and modifying the CCOC and inner bypass ducts. This AD also prohibits 
installation of certain flange bolts on any affected engine, as 
specified in a Transport Canada AD, which is proposed for incorporation 
by reference (IBR). The FAA is issuing this AD to address the unsafe 
condition on these products.

DATES: This AD is effective May 30, 2023.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of May 30, 
2023.

ADDRESSES: 
    AD Docket: You may examine the AD docket at regulations.gov under 
Docket No. FAA-2023-0022; or in person at Docket Operations between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD 
docket contains this final rule, the mandatory continuing airworthiness 
information (MCAI), any comments received, and other information. The 
address for Docket Operations is U.S. Department of Transportation, 
Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 
New Jersey Avenue SE, Washington, DC 20590.
    Material Incorporated by Reference:
     For service information identified in this final rule, 
contact Transport Canada, Transport Canada National Aircraft 
Certification, 159 Cleopatra Drive, Nepean, Ontario K1A 0N5, Canada; 
phone: (888) 663-3639; email: [email protected]. You may find this material on the 
Transport Canada website at tc.canada.ca/en/aviation.
     You may view this service information at the FAA, 
Airworthiness Products Section, Operational Safety Branch, 1200 
District Avenue, Burlington, MA 01803. For information on the 
availability of this material at the FAA, call (817) 222-5110. It is 
also available at regulations.gov under Docket No. FAA-2023-0022.

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

SUPPLEMENTARY INFORMATION: 

Background

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 by adding an AD that would apply to P&WC PW308A model 
turbofan engines with build specification (BS) BS935 and BS1249, serial 
numbers PCE-CE0180 and prior, and PW308C model turbofan engines with 
BS1047 and BS1238, serial numbers PCE-CF0967 and prior. The NPRM 
published in the Federal Register on January 24, 2023 (88 FR 4111). The 
NPRM was prompted by Transport Canada AD CF-2022-22, dated April 25, 
2022 (Transport Canada AD CF-2022-22), issued by Transport Canada, 
which is the aviation authority for Canada (referred to after this as 
the MCAI). The MCAI states that during a design review, the 
manufacturer identified that the existing low cycle fatigue life of the 
flange bolts that secure the CCOC and the RCC is inadequate. As of May 
6, 2022 (the effective date of Transport Canada AD CF-2022-22), there 
have been no reports of cracked flange bolts, however the MCAI states 
there is potential that cracks could develop on the flange bolt, which 
could lead to fracture of the bolt. The MCAI also states that to 
address the potential cracking issue, P&WC introduced redesigned flange 
bolts made of an improved fatigue resistant material. P&WC also 
introduced revised procedures to modify the CCOC and the inner bypass 
duct flange with chamfers to reverse the installation direction of the 
flange bolts. The MCAI specifies installation of the redesigned bolt 
configuration, modifications to the CCOC and inner bypass duct, and 
specifies an installation prohibition for flange bolts with part 
numbers MS9698-08 or MS9698-09 on the affected engines.
    In the NPRM, the FAA proposed to require replacing all CCOC flange 
bolts and modifying the CCOC and inner bypass ducts. The NPRM also 
proposed to prohibit installation of flange bolts with part numbers 
MS9698-08 and MS9698-09 on any affected engine, as specified in 
Transport Canada AD CF-2022-22. The FAA is issuing this AD to address 
the unsafe condition on these products.
    You may examine the MCAI in the AD docket at regulations.gov under 
Docket No. FAA-2023-0022.

Discussion of Final Airworthiness Directive

Comments

    The FAA received one anonymous comment that supported the NPRM 
without change.

Conclusion

    These products have been approved by the aviation authority of 
another country and are approved for operation in the United States. 
Pursuant to the FAA's bilateral agreement with this State of Design 
Authority, it has notified the FAA of the unsafe condition described in 
the MCAI referenced above. The FAA reviewed the relevant data, 
considered the comment received, and determined that air safety 
requires adopting this AD as proposed. Accordingly, the FAA is issuing 
this AD to address the unsafe condition on these products. Except for 
minor editorial

[[Page 24898]]

changes, this AD is adopted as proposed in the NPRM.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Transport Canada AD CF-2022-22, which specifies 
instructions for replacing certain CCOC flange bolts and modifying the 
CCOC and inner bypass ducts. Transport Canada AD CF-2022-22 also 
specifies an installation prohibition for flange bolts with part 
numbers MS9698-08 and MS9698-09 on the affected engines.
    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 668 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
----------------------------------------------------------------------------------------------------------------
Remove and replace all CCOC flange      1.5 work-hours x $85 per          $7,742          $7,870      $5,257,160
 bolts.                                  hour = $128.
Modify the CCOC and inner bypass ducts  1.5 work-hours x $85 per               0             128          85,504
                                         hour = $128.
----------------------------------------------------------------------------------------------------------------

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, section 106, describes the 
authority of the FAA Administrator. Subtitle VII: Aviation Programs, 
describes in more detail the scope of the Agency's authority.
    The FAA is issuing this rulemaking under the authority described in 
Subtitle VII, Part A, Subpart III, Section 44701: General requirements. 
Under that section, Congress charges the FAA with promoting safe flight 
of civil aircraft in air commerce by prescribing regulations for 
practices, methods, and procedures the Administrator finds necessary 
for safety in air commerce. This regulation is within the scope of that 
authority because it addresses an unsafe condition that is likely to 
exist or develop on products identified in this rulemaking action.

Regulatory Findings

    This AD will not have federalism implications under Executive Order 
13132. This AD will not have a substantial direct effect on the States, 
on the relationship between the national government and the States, or 
on the distribution of power and responsibilities among the various 
levels of government.
    For the reasons discussed above, I certify that this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Will not affect intrastate aviation in Alaska, and
    (3) Will not have a significant economic impact, positive or 
negative, on a substantial number of small entities under the criteria 
of the Regulatory Flexibility Act.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

The Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

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:

2023-06-14 Pratt & Whitney Canada Corporation: Amendment 39-22400; 
Docket No. FAA-2023-0022; Project Identifier MCAI-2022-00564-E.

(a) Effective Date

    This airworthiness directive (AD) is effective May 30, 2023.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to:
    (1) Pratt & Whitney Canada Corporation (P&WC) PW308A model 
turbofan engines with build specification (BS) BS935 and BS1249, 
serial numbers PCE-CE0180 and prior; and
    (2) P&WC PW308C model turbofan engines with BS1047 and BS1238, 
serial numbers PCE-CF0967 and prior.

(d) Subject

    Joint Aircraft Service Component (JASC) Code 7240, Turbine 
Engine Combustion Section.

(e) Unsafe Condition

    This AD was prompted by a manufacturer's design review which 
identified that the combustion chamber outer case to rear compressor 
case flange bolts low cycle fatigue life was inadequate, and that 
those flange bolts may develop cracks resulting in flange bolt 
fracture. The FAA is issuing this AD to prevent cracking and 
fracture of the flange bolts. The unsafe condition, if not 
addressed, may result in flange bolt fracture, flange separation or 
case rupture, 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

    Except as specified in paragraphs (h) and (i) of this AD: 
Perform all required actions within the compliance times specified 
in, and in accordance with, Transport Canada AD CF-2022-22.

(h) Exceptions to Transport Canada AD CF-2022-22

    Where Transport Canada AD CF-2022-22 requires compliance from 
its effective date, this AD requires using the effective date of 
this AD.

(i) No Reporting Requirement

    Although the service information referenced in Transport Canada 
AD CF-2022-22 specifies to submit certain information to the 
manufacturer, this AD does not include that requirement.

(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 or email 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.

[[Page 24899]]

(k) Additional Information

    For more information about this AD, contact Barbara Caufield, 
Aviation Safety Engineer, ECO Branch, FAA, 1200 District Avenue, 
Burlington, MA 01803; phone: (781) 238-7146; email: 
[email protected].

(l) 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 AD CF-2022-22, dated April 22, 2022.
    (ii) [Reserved]
    (3) For Transport Canada AD CF-2022-22, contact Transport 
Canada, Transport Canada National Aircraft Certification, 159 
Cleopatra Drive, Nepean, Ontario K1A 0N5, Canada; phone: (888) 663-
3639; email: [email protected]. You may find this material on 
the Transport Canada website at tc.canada.ca/en/aviation.
    (4) 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 (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: [email protected], or go to: www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued on March 24, 2023.
Christina Underwood,
Acting Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2023-08624 Filed 4-24-23; 8:45 am]
BILLING CODE 4910-13-P


