DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-1071; Project Identifier AD-2021-01055-E;
Amendment 39-22044; AD 2022-10-06]
RIN 2120-AA64

Airworthiness Directives; Rolls-Royce Corporation Turboshaft Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: The FAA is superseding Airworthiness Directive (AD) 2017-18-
14, which applied to certain Rolls-Royce Corporation (RRC) 250 model
turboshaft engines. AD 2017-18-14 required repetitive visual
inspections and fluorescent penetrant inspections (FPIs) of the 3rd-
stage turbine wheel and removal from service of the 4th-stage turbine
wheel. This AD was prompted by in-service turbine blade failures that
resulted in the loss of power and engine in-flight shutdowns. This AD
requires replacement of the 3rd-stage and 4th-stage turbine wheels.
This AD also revises the applicability to include an additional
turboshaft engine model. The FAA is issuing this AD to address the
unsafe condition on these products.

DATES: This AD is effective June 28, 2022.

ADDRESSES: For service information identified in this final rule,
contact Rolls-Royce Corporation, 450 South Meridian Street, Mail Code
NB-01-06, Indianapolis, IN 46225; phone: (317) 230-2720; email:
HelicoptCustSupp@Rolls-Royce.com; website: www.rolls-royce.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 (817) 222-5110.

Examining the AD Docket

You may examine the AD docket at https://www.regulations.gov by
searching for and locating Docket No. FAA-2021-1071; 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: John Tallarovic, Aviation Safety
Engineer, Chicago ACO, FAA, 2300 E Devon Avenue, Des Plaines, IL 60018;
phone: (847) 294-8180; email: john.m.tallarovic@faa.gov.

SUPPLEMENTARY INFORMATION:

Background

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 to supersede AD 2017-18-14, Amendment 39-19023 (82 FR
42443, September 8, 2017), (AD 2017-18-14). AD 2017-18-14 applied to
certain RRC 250-C20, -C20B, -C20F, -C20J, -C20R, -C20R/1, -C20R/2, -
C20R/4, -C20W, -C300/A1, and -C300/B1 turboshaft engines with either a
3rd-stage turbine wheel, part number (P/N) 23065818, or a 4th-stage
turbine wheel, P/N 23055944 or RR30000240, installed. The NPRM
published in the Federal Register on January 14, 2022 (87 FR 2365). The
NPRM was prompted by in-service turbine blade failures that resulted in
the loss of power and engine in-flight shutdowns. Since the FAA issued
AD 2017-18-14, the manufacturer redesigned the 3rd-stage turbine wheel.
The manufacturer published Rolls-Royce Alert Commercial Engine Bulletin
(CEB) CEB A-1428/CEB A-72-4111 (single document), which describes
procedures for replacement of the 3rd-stage turbine wheel, P/N
23065818, with the new increased blade fillet 3rd-stage turbine wheel,
P/N M250-10473. Additionally, the FAA determined that the RRC 250-C20C
(T63-A-720) model turboshaft engine is also susceptible to the unsafe
condition. In the NPRM, the FAA proposed to require replacement of the
3rd-stage and 4th-stage turbine wheels. The FAA is issuing this AD to address
the unsafe condition on these products.

Discussion of Final Airworthiness Directive

Comments

The FAA received comments from two commenters. The commenters were
an anonymous commenter and RRC. The following presents the comments
received on the NPRM and the FAA's response to each comment.

Comments on Part Availability and Costs

The anonymous commenter stated that RRC does not have the inventory
to supply engine shops with the 3rd-stage and 4th-stage turbine wheels
proposed for replacement in the NPRM. The commenter requested that RRC
provide credit to its customers for unused time on 3rd-stage and 4th-
stage turbine wheels and reasoned that customers paid for the full life
of the 3rd-stage and 4th-stage turbine wheels, not a partial life,
which now requires replacement at full price. The commenter also stated
that the part cost estimates in the NPRM for the 3rd-stage and 4th-
stage turbine wheels are inaccurate and should indicate an estimated
cost of $22,929.15 and $18,926.59 to reflect Aviall and Boeing's
prices, respectively. The commenter noted that they have found
performing FPIs on the 3rd-stage and 4th-stage turbine wheels result in
serviceable conditions compared to the previous configurations that
were beyond serviceable. The commenter expressed that the proposed
requirements in the NPRM would be a financial burden on RRC's
customers, considering the current market instability.
The FAA disagrees that the manufacturer will not have sufficient
inventory, which would prevent compliance with this AD. Prior to
publishing the NPRM, the FAA confirmed with RRC that there would be
adequate inventory for operators to replace the 3rd-stage and 4th-stage
turbine wheels. In response to this comment, the FAA confirmed with RRC
that the 3rd-stage and 4th-stage turbine wheels are available at a 50%
discounted price. Additionally, RRC indicated that suppliers will also
provide the discounted price. The FPI of 3rd-stage turbine wheels was
an interim action until redesigned parts became available. While FPI
reduces the risk of a blade failure, the unsafe condition is addressed
by replacing the 3rd-stage turbine wheel with the revised design. The
FAA did not change this AD as a result of the comments.

Request To Update Service Information

RRC requested that the FAA revise the Related Service Information
paragraph of this AD to reference Rolls-Royce Alert CEB CEB A-1428/CEB
A-72-4111 (single document), Revision 2, dated December 8, 2021. RRC
reasoned that since the three Rolls-Royce bulletins were submitted to
the FAA in support of the NPRM, Rolls-Royce has published Revision 2 of
Rolls-Royce Alert CEB CEB A-1428/CEB A-72-4111 (single document).
The FAA agrees. The FAA has updated the Related Service Information
paragraph of this AD to reference Rolls-Royce Alert CEB CEB A-1428/CEB
A-72-4111 (single document), Revision 2, dated December 8, 2021.

Conclusion

The FAA reviewed the relevant data, considered any 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. Except for minor editorial changes, and
any other changes described previously, this AD is adopted as proposed
in the NPRM. None of the changes will increase the economic burden on
any operator.

Related Service Information

The FAA reviewed Rolls-Royce Alert CEB CEB A-1428/CEB A-72-4111
(single document), Revision 2, dated December 8, 2021. This Alert CEB
describes procedures for replacing the 3rd-stage turbine wheel, P/N
23065818, with the new increased blade fillet 3rd-stage turbine wheel,
P/N M250-10473.
The FAA reviewed Rolls-Royce Alert CEB CEB-A-1422/CEB-A-72-4108
(single document), Original Issue, dated September 13, 2017. This Alert
CEB describes procedures for replacing 4th-stage turbine wheel, P/N
23055944, with the new increased blade fillet 4th-stage turbine wheel,
P/N M250-10445.
The FAA also reviewed Rolls-Royce Alert Service Bulletin (SB)
RR300-A-72-024, Original Issue, dated September 13, 2017. This Alert SB
describes procedures for replacing the 4th-stage turbine wheel, P/N
RR30000240, with the new increased blade fillet 4th-stage turbine
wheel, P/N RR30000494.

Costs of Compliance

The FAA estimates that this AD affects 3,769 engines installed on
helicopters of U.S. registry. The FAA estimates that 3,041 3rd-stage
turbine wheels and 3,769 4th-stage turbine wheels will require
replacement.
The FAA estimates the following costs to comply with this AD:

Estimated Costs

The FAA has included all known costs in its cost estimate.
According to the manufacturer, however, some of the costs of this AD
may be covered under warranty, thereby reducing the cost impact on
affected operators.

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 2017-18-14, Amendment 39-19023 (82
FR 42443, September 8, 2017); and

b. Adding the following new airworthiness directive: