preamble attached >>>
ADs updated daily at www.Tdata.com
2025-05-13 PRATT & WHITNEY CANADA CORP.: Amendment 39-22985; Docket No. FAA-2024-2539; Project Identifier MCAI-2023-00971-E.
(a) EFFECTIVE DATE

    This airworthiness directive (AD) is effective April 23, 2025.

(b) AFFECTED ADS

    None.

(c) APPLICABILITY

    This AD applies  to Pratt &  Whitney Canada Corp.  (P&WC) Model PW535E
    and PW535E1 engines, as identified in Transport Canada Civil  Aviation
    AD CF-2023-60, dated August 14, 2023 (Transport Canada AD CF-2023-60).

(d) SUBJECT

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

(e) UNSAFE CONDITION

    This AD was  prompted by a  manufacturer design review  that indicated
    certain  flange  bolts securing  the  gas generator  case  and turbine
    support case  have an  inadequate low-cycle  fatigue life.  The FAA is
    issuing this AD to prevent  crack, fracture, missing, or loosening  of
    the gas generator  case to turbine  support case retaining  bolts. The
    unsafe condition, if not addressed, could result in uncontained engine
    debris, 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-2023-60.

(h) EXCEPTIONS TO TRANSPORT CANADA AD CF-2023-60

(1) Where  Transport  Canada AD  CF-2023-60 requires  compliance from  its
    effective  date, this AD requires using the effective date of this AD.

(2) Where  paragraph  A.1. of  Transport  Canada  AD CF-2023-60  refers to
    "discrepancy," this AD defines that as "evidence of bolt cracks,  bolt
    fracture, missing bolts, or loose bolts."

(3) Where paragraph  A.2. in Transport  Canada AD CF-2023-60  specifies to
    "Repeat  the  above   paragraph  A.1.  inspection   and  rectification
    requirements of this AD at intervals not to exceed 400 engine cycles,"
    this AD requires replacing that text with "Repeat the above  paragraph
    A.1. inspection and rectification  requirements of this AD  thereafter
    at intervals not to exceed 400 engine cycles."

(4) Where paragraph  A.1. in Transport  Canada AD CF-2023-60  specifies to
    "Inspect the bolts P/N MS9696-08  and P/N MS9489-06 within 400  cycles
    from the effective date of  this AD," this AD requires  replacing that
    text with "Inspect affected bolts having P/N MS9696-08 and P/N MS9489-
    06 within 400 engine cycles from the effective date of this AD."

(5) Where paragraph  A.1. in Transport  Canada AD CF-2023-60  specifies to
    "rectify  any  discrepancy  in  accordance  with  the   Accomplishment
    Instructions of the  applicable SB," this  AD requires replacing  that
    text with "Following inspection, if any bolts are determined to be  in
    an  unserviceable  condition,  before  further  flight,  replace   the
    affected bolts in accordance with the applicable SB."

(i) NO REPORTING REQUIREMENT

    Although the service information referenced in Transport Canada AD  CF
    -2023-60 specifies to submit certain information to the  manufacturer,
    this AD does not include that requirement.

(j) ALTERNATIVE METHODS OF COMPLIANCE (AMOCS)

    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  local  Flight
    Standards  District  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
    (k) of this AD and email to: 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.

(k) 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: barbara.caufield@faa.gov.

(l) MATERIAL INCORPORATED BY REFERENCE

(1) The  Director of  the Federal  Register approved  the incorporation by
    reference of  the material  listed in  this paragraph  under 5  U.S.C.
    552(a) and 1 CFR part 51.

(2) You must use this material as applicable to do the actions required by
    this AD, unless the AD specifies otherwise.

(i) Transport Canada AD CF-2023-60, dated August 14, 2023.

(ii) [Reserved]

(3) For Transport Canada material identified in this AD, contact Transport
    Canada,  Transport   Canada  National   Aircraft  Certification,   159
    Cleopatra  Drive, Nepean, Ontario  K1A 0N5, Canada;  phone: (888) 663-
    3639; email: TC.AirworthinessDirectives-Consignesdenavigabilite.TC@tc.
    gc.ca; website: tc.canada.ca/en/aviation.

(4) You may view this material 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.

(5) You may view this material at the National Archives and Records Admin-
    istration (NARA). For information on the availability of this material
    at NARA, visit www.archives.gov/federal-register/cfr/ibr-locations  or
    email fr.inspection@nara.gov.

Issued  on March  6, 2025.  Peter A.  White, Deputy  Director,  Integrated
Certificate Management Division, Aircraft Certification Service.

FOR  FURTHER  INFORMATION  CONTACT:  Barbara  Caufield,  Aviation   Safety
Engineer, FAA, 2200 South 216th Street, Des Moines, WA 98198; phone: (781)
238-7146; email: barbara.caufield@faa.gov.
PREAMBLE 

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2024-2539; Project Identifier MCAI-2023-00971-E;
Amendment 39-22985; AD 2025-05-13]
RIN 2120-AA64

Airworthiness Directives; Pratt & Whitney Canada Corp. 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 Corp. (P&WC) Model PW535E and PW535E1
engines. This AD was prompted by a manufacturer design review that
indicated certain flange bolts securing the gas generator case and
turbine support case are susceptible to cracking at their current low-
cycle fatigue (LCF) life. This AD requires repetitive borescope
inspections (BSI) of the gas generator case to turbine support case
retaining bolts for evidence of bolt cracks, bolt fracture, missing
bolts, or loose bolts and replacement, if necessary, as specified in a
Transport Canada 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 April 23, 2025.

The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of April 23, 2025.

ADDRESSES:

AD Docket: You may examine the AD docket at regulations.gov under
Docket No.FAA-2024-2539; 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 Transport Canada material identified in this AD,
contact Transport Canada, Transport Canada National Aircraft
Certification, 159 Cleopatra Drive, Nepean, Ontario, K1A 0N5, Canada;
phone: (888) 663-3639; email: TC.AirworthinessDirectives-Consignesdenavigabilite.
TC@tc.gc.ca; website: tc.canada.ca/en/aviation.

You may view this material 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-2024-2539.

FOR FURTHER INFORMATION CONTACT: Barbara Caufield, Aviation Safety
Engineer, FAA, 2200 South 216th Street, Des Moines, WA 98198; phone:
(781) 238-7146; email: barbara.caufield@faa.gov.

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 certain P&WC Model
PW535E and PW535E1 engines. The NPRM published in the Federal Register
on November 26, 2024 (89 FR 93225). The NPRM was prompted by Transport
Canada AD CF-2023-60, dated August 14, 2023 (Transport Canada AD CF-
2023-60) (also referred to as the MCAI), issued by Transport Canada,
which is the aviation authority for Canada. The MCAI states that data
from a design review by the manufacturer identified insufficient LCF
life for flange bolts, having part number (P/N) MS9696-08 and P/N
MS9489-06, that secure the engine gas generator and turbine support
cases. At certain high-stress circumferential locations, LCF cracks
could develop on the flange bolt and lead to fracture of the bolt.
Multiple fractured bolts could lead to flange separation or case
rupture, which may damage the engine and the airplane. To address this
unsafe condition, the manufacturer published material that provides
instructions for repetitive BSIs and replacement of the affected parts.

In the NPRM, the FAA proposed to require repetitive BSI of the gas
generator case to turbine support case retaining bolts for evidence of
bolt cracks, bolt fracture, missing bolts, or loose bolts, and
replacement, if necessary. 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-2024-2539.

Discussion of Final Airworthiness Directive

Comments


The FAA received no comments on the NPRM or on the determination of
the costs.

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

Material Incorporated by Reference Under 1 CFR Part 51

The FAA reviewed Transport Canada AD CF-2023-60, which identifies
the affected gas generator case to turbine support case retaining bolts
and specifies procedures for repetitive BSIs and replacement.

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 the ADDRESSES section.

Differences Between This AD and the MCAI

Where the service information referenced in Transport Canada AD CF-
2023-60 requires reporting certain information to the manufacturer,
this AD does not require such a submission.

Costs of Compliance

The FAA estimates that this AD affects 521 engines installed on
airplanes of U.S. registry.

The FAA estimates the following costs to comply with this AD:

Estimated Costs

ACTION
LABOR COST
PARTS COST
COST PER PRODUCT
COST ON U.S. OPERATORS
BSI of gas generator case to turbine support case retaining bolts. 2 work-hours x $85 per hour = $170.
$0
$170
$88,570

The FAA estimates the following costs to do any necessary
replacements that are required based on the results of the inspection.
The agency has no way of determining the number of engines that might
need these replacements:

On-Condition Costs

ACTION
LABOR COST
PARTS COST
COST PER PRODUCT
Replacement of the gas generator case to turbine support case retaining bolts. 4 work-hours x $85 per hour = $340.
$337,701
$338,041

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


1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. 106(f), 40113, 44701.

Sec. 39.13 [Amended]


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