[Federal Register Volume 88, Number 67 (Friday, April 7, 2023)]
[Proposed Rules]
[Pages 20782-20784]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-07182]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2023-0660; Project Identifier MCAI-2022-01561-E]
RIN 2120-AA64


Airworthiness Directives; Rolls-Royce Deutschland Ltd & Co KG 
Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for certain Rolls-Royce Deutschland Ltd & Co KG (RRD) Trent 1000 model 
turbofan engines. This proposed AD was prompted by reports of excessive 
wear on the inner seal fins of certain high-pressure turbine (HPT) 
triple seals. This proposed AD would require an inspection of the HPT 
triple seal for excessive wear and, depending on the results of the 
inspection, replacement of the HPT triple seal and the intermediate-
pressure turbine (IPT) disk, as specified in a European Union Aviation 
Safety Agency (EASA) AD, which is proposed for incorporation by 
reference (IBR). The FAA is proposing this AD to address the unsafe 
condition on these products.

DATES: The FAA must receive comments on this NPRM by May 22, 2023.

ADDRESSES: You may send comments, using the procedures found in 14 CFR 
11.43 and 11.45, by any of the following methods:
     Federal eRulemaking Portal: Go to regulations.gov. Follow 
the instructions for submitting comments.
     Fax: (202) 493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE, Washington, DC 20590.
     Hand Delivery: Deliver to Mail address above between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    AD Docket: You may examine the AD docket at regulations.gov under 
Docket No. FAA-2023-0660; 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 NPRM, the mandatory continuing airworthiness 
information (MCAI), any comments received, and other information. The 
street address for Docket Operations is listed above.
    Material Incorporated by Reference:
     For EASA service information that is proposed for IBR in 
this NPRM, contact EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, 
Germany; phone: +49 221 8999 000; email: [email protected]; website: 
easa.europa.eu. You may find this material on the EASA website at 
ad.easa.europa.eu.
     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-2023-0660.

FOR FURTHER INFORMATION CONTACT: Sungmo Cho, Aviation Safety Engineer, 
ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803; phone: 
(781) 238-7241; email: [email protected].

SUPPLEMENTARY INFORMATION: 

Comments Invited

    The FAA invites you to send any written relevant data, views, or 
arguments about this proposal. Send your comments to an address listed 
under ADDRESSES. Include ``Docket No. FAA-2023-0660; Project Identifier 
MCAI-2022-01561-E'' at the beginning of your comments. The most helpful 
comments reference a specific portion of the proposal, explain the 
reason for any recommended change, and include supporting data. The FAA 
will consider all comments received by the closing date and may amend 
this proposal because of those comments.
    Except for Confidential Business Information (CBI) as described in 
the following paragraph, and other information as described in 14 CFR 
11.35, the FAA will post all comments received, without change, to 
regulations.gov, including any personal information you provide. The 
agency will also post a report summarizing each substantive verbal 
contact received about this NPRM.

Confidential Business Information

    CBI is commercial or financial information that is both customarily 
and actually treated as private by its owner. Under the Freedom of 
Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public 
disclosure. If your comments responsive to this NPRM contain commercial 
or financial information that is customarily treated as private, that 
you actually treat as private, and that is relevant or responsive to 
this NPRM, it is important that you clearly designate the submitted 
comments as CBI. Please mark each page of your submission containing 
CBI as ``PROPIN.'' The FAA will treat such marked submissions as 
confidential under the FOIA, and they will not be placed in the public 
docket of this NPRM. Submissions containing CBI should be sent to 
Sungmo Cho, Aviation Safety Engineer, ECO Branch, FAA, 1200 District 
Avenue, Burlington, MA 01803. Any commentary that the FAA receives 
which is not specifically designated as CBI will be placed in the 
public docket for this rulemaking.

Background

    EASA, which is the Technical Agent for the Member States of the 
European Union, has issued EASA AD 2022-0241, dated December 7, 2022 
(EASA AD 2022-0241) (also referred to as the MCAI), to correct an 
unsafe condition for certain RRD Trent 1000-AE3, Trent 1000-CE3, Trent 
1000-D3, Trent 1000-G3, Trent 1000-H3, Trent 1000-J3, Trent 1000-K3, 
Trent 1000-L3, Trent 1000-M3, Trent 1000-N3, Trent 1000-P3, Trent 1000-
Q3, and Trent 1000-R3 model turbofan engines. The MCAI states that 
occurrences have been reported of finding higher than expected levels 
of wear on the seal fins of certain HPT triple seals. The secondary air 
system is affected by the resulting increased turbine cooling air 
leakage, which changes the air flow around the IPT disk.
    The Modulated Air System (MAS) was designed to optimize cooling air 
flow and intended to be active only during cruise conditions, but the 
design did not account for a high level of seal wear. Rolls-Royce 
issued Non-Modification Service Bulletin Trent 1000 75-AK642, Initial 
Issue, dated November 30, 2020, to provide instructions for MAS 
deactivation, and consequently, EASA published EASA AD 2021-0009, dated 
January 8, 2021, specifying deactivation of the MAS control valves. 
Despite this, a significantly worn HPT triple seal under flight 
conditions, while MAS was activated prior to the above action, could 
have reduced the safety of flight.
    You may examine the MCAI in the AD docket at regulations.gov under 
Docket No. FAA-2023-0660.

[[Page 20783]]

Related Service Information Under 1 CFR Part 51

    The FAA reviewed EASA AD 2022-0241, which specifies procedures for 
inspecting the HPT triple seal for excessive wear and, depending on the 
results of the inspection, replacing the HPT triple seal and the IPT 
disk.
    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.

FAA's Determination

    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 described above. The FAA is issuing this NPRM after 
determining that the unsafe condition described previously is likely to 
exist or develop on other products of these same type designs.

Proposed AD Requirements in This NPRM

    This proposed AD would require accomplishing the actions specified 
in EASA AD 2022-0241 described previously, except for any differences 
identified as exceptions in the regulatory text of this proposed AD.

Explanation of Required Compliance Information

    In the FAA's ongoing efforts to improve the efficiency of the AD 
process, the FAA developed a process to use some civil aviation 
authority (CAA) ADs as the primary source of information for compliance 
with requirements for corresponding FAA ADs. The FAA has since 
coordinated with other manufacturers and CAAs to use this process. As a 
result, the FAA proposes to incorporate by reference EASA AD 2022-0241 
in the FAA final rule. This proposed AD would, therefore, require 
compliance with EASA AD 2022-0241 in its entirety through that 
incorporation, except for any differences identified as exceptions in 
the regulatory text of this proposed AD. Using common terms that are 
the same as the heading of a particular section in the EASA AD does not 
mean that operators need comply only with that section. For example, 
where the AD requirement refers to ``all required actions and 
compliance times,'' compliance with this AD requirement is not limited 
to the section titled ``Required Action(s) and Compliance Time(s)'' in 
EASA AD 2022-0241. Service information required by the EASA AD for 
compliance will be available at regulations.gov by searching for and 
locating Docket No. FAA-2023-0660 after the FAA final rule is 
published.

Costs of Compliance

    The FAA estimates that this AD, if adopted as proposed, would 
affect 4 engines installed on airplanes of U.S. registry.
    The FAA estimates the following costs to comply with this proposed 
AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                    Cost per       Cost on U.S.
               Action                        Labor cost           Parts cost        product         operators
----------------------------------------------------------------------------------------------------------------
Inspect HPT triple seal.............  1 work-hour x $85 per                $0              $85             $340
                                       hour = $85.
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    The FAA estimates the following costs to do any necessary 
replacements that would be required based on the results of the 
proposed inspection. The agency has no way of determining the number of 
aircraft that might need these replacements:

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                     Cost per
                    Action                                Labor Cost               Parts Cost        product
----------------------------------------------------------------------------------------------------------------
Replace HPT triple seal and IPT disk.........  4 work-hours x $85 per hour =          $737,832         $738,172
                                                $340.
----------------------------------------------------------------------------------------------------------------

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 determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD would 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 this proposed 
regulation:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Would not affect intrastate aviation in Alaska, and
    (3) Would 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 Proposed Amendment

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

[[Page 20784]]

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:

Rolls-Royce Deutschland Ltd & Co KG: Docket No. FAA-2023-0660; 
Project Identifier MCAI-2022-01561-E.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by May 22, 2023.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to certain Rolls-Royce Deutschland Ltd & Co KG 
(RRD) Trent 1000-AE3, Trent 1000-CE3, Trent 1000-D3, Trent 1000-G3, 
Trent 1000-H3, Trent 1000-J3, Trent 1000-K3, Trent 1000-L3, Trent 
1000-M3, Trent 1000-N3, Trent 1000-P3, Trent 1000-Q3, and Trent 
1000-R3 model turbofan engines, as identified in European Union 
Aviation Safety Agency (EASA) AD 2022-0241, dated December 7, 2022 
(EASA AD 2022-0241).

(d) Subject

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

(e) Unsafe Condition

    This AD was prompted by reports of excessive wear on the inner 
seal fins of certain high-pressure turbine (HPT) triple seals. The 
FAA is issuing this AD to prevent excessive wear on the inner seal 
fins of certain HPT triple seals. The unsafe condition, if not 
addressed, could lead to a temperature increase at the intermediate-
pressure turbine (IPT) disk rim, possibly resulting in IPT disk 
failure and high energy debris release, with consequent damage to 
the airplane and reduced control of 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, EASA AD 2022-0241.

(h) Exceptions to EASA AD 2022-0241

    (1) Where EASA AD 2022-0241 refers to its effective date, this 
AD requires using the effective date of this AD.
    (2) This AD does not adopt the Remarks paragraph of EASA AD 
2022-0241.

(i) No Reporting Requirement

    Although EASA AD 2022-0241 specifies to submit inspection 
results 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 and 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.

(k) Additional Information

    For more information about this AD, contact Sungmo Cho, Aviation 
Safety Engineer, ECO Branch, FAA, 1200 District Avenue, Burlington, 
MA 01803; phone: (781) 238-7241; 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) European Union Aviation Safety Agency AD 2022-0241, dated 
December 7, 2022.
    (ii) [Reserved]
    (3) For EASA AD 2022-0241, contact EASA, Konrad-Adenauer-Ufer 3, 
50668 Cologne, Germany; phone: +49 221 8999 000; email: 
[email protected]; website: easa.europa.eu. You may find this EASA 
AD on the EASA website at ad.easa.europa.eu.
    (4) 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.
    (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 31, 2023.
Christina Underwood,
Acting Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2023-07182 Filed 4-6-23; 8:45 am]
BILLING CODE 4910-13-P