DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2022-1478; Project Identifier MCAI-2022-00668-E;
Amendment 39-22337; AD 2023-03-12]
RIN 2120-AA64

Airworthiness Directives; Pratt & Whitney Canada Corp. Turbofan
Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: The FAA is superseding Airworthiness Directive (AD) 2004-04-
09, which applied to certain Pratt & Whitney Canada Corp. (P&WC) JT15D-
1, JT15D-1A, and JT15D-1B model turbofan engines. AD 2004-04-09
required a one-time borescope inspection (BSI) of the rear face of
certain impellers for evidence of a machined groove or step, and repair
or replacement of the impeller if a groove or step is found. Since the
FAA issued AD 2004-04-09, the FAA was notified of an uncontained
failure of an impeller installed on a P&WC JT15D-1A engine during
takeoff and subsequent investigation by the manufacturer that
discovered machining marks on the impeller. This AD was prompted by
three prior reports of uncontained failure of the impeller, and one
additional recent report of an in-service uncontained failure event.
This AD requires borescope fluorescent penetrant inspection (FPI) of
the rear face of certain impellers for evidence of machining witness
lines and, depending on the results of the inspection, replacement of
the impeller, 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 March 31, 2023.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of March 31,
2023.

ADDRESSES:
AD Docket: You may examine the AD docket at regulations.gov under
Docket No. FAA-2022-1478; 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 service information incorporated by
reference in this AD, contact Transport Canada, Transport Canada
National Aircraft Certification, 159 Cleopatra Drive, Nepean, Ontario
K1A 0N5, Canada; phone: (888) 663-3639; email: AD-CN@tc.gc.ca; website:
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 in the AD docket at regulations.gov under Docket No.
FAA-2022-1478.

FOR FURTHER INFORMATION CONTACT: Barbara Caufield, Aviation Safety
Engineer, ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803;
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 to supersede AD 2004-04-09, Amendment 39-13490 (69 FR 9520,
March 1, 2004) (AD 2004-04-09). AD 2004-04-09 applied to certain P&WC
JT15D-1, JT15D-1A, and JT15D-1B model turbofan engines. AD 2004-04-09
required a one-time BSI of the rear face of certain impellers for
evidence of a machined groove or step, and repair or replacement of the
impeller if a groove or step is found. The FAA issued AD 2004-04-09 to
prevent uncontained failure of the impeller and possible damage to the
airplane.
The NPRM published in the Federal Register on November 18, 2022 (87
FR 69231). The NPRM was prompted by AD CF-2022-27, dated May 19, 2022
(Transport Canada AD CF-2022-27), issued by Transport Canada, which is
the aviation authority for Canada (referred to after this as the MCAI).
The MCAI states that there has been one recent in-service event of a
JT15D-1A engine uncontained failure during a takeoff roll of the
airplane. An investigation by P&WC has determined that a crack
originated from machining marks on the back face of the impeller and
subsequently propagated until the impeller fractured. There is evidence
that the event engine had been previously inspected in accordance with
P&WC Service Bulletin (SB) No. JT15D-72-7590, dated May 23, 2003
(mandated by Transport Canada AD CF-2003-17, dated June 23, 2003), but
it appears that the machining marks were not detected. P&WC, therefore,
published P&WC SB JT15D-72-7655, Original Issue, dated April 14, 2022,
to inspect the rear face of the impeller using a new borescope FPI
procedure. As a result, Transport Canada issued AD CF-2022-27 to
require accomplishment of the borescope FPI at the next hot section
inspection until the impeller, part number 3020365, is replaced at the
next scheduled engine overhaul.
You may examine the MCAI in the AD docket at regulations.gov under
Docket No. FAA-2022-1478.
In the NPRM, the FAA proposed to require borescope FPI of the rear
face of certain impellers for evidence of machining witness lines and,
depending on the results of the inspection, replacement of the
impeller, as specified in Transport Canada AD CF-2022-27. The FAA is
issuing this AD to address the unsafe condition on these products.

Discussion of Final Airworthiness Directive

Comments

The FAA received no comments on the NPRM or on the determination of
the cost to the public.

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.

Related Service Information Under 1 CFR Part 51

The FAA reviewed Transport Canada AD CF-2022-27, which specifies
instructions for performing a one-time inspection of the rear face of
the impeller and replacing the impeller if unacceptable machining
witness lines or crack indications are found. Transport Canada AD CF-
2022-27 also specifies instructions for replacing the impeller at the
next scheduled engine overhaul. 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 100 engines installed on
airplanes of U.S. registry.
The FAA estimates the following costs to comply with this AD:

Estimated Costs

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

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]

2. The FAA amends Sec. 39.13 by:

a. Removing Airworthiness Directive 2004-04-09, Amendment 39-13490 (69
FR 9520, March 1, 2004); and

b. Adding the following new airworthiness directive: