```

[Federal Register Volume 89, Number 22 (Thursday, February 1, 2024)]
[Proposed Rules]
[Pages 6450-6452]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-01976]

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

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2024-0043; Project Identifier MCAI-2023-00985-E]
RIN 2120-AA64

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

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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

SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for all Rolls-Royce Deutschland Ltd & Co KG (RRD) Model Trent 1000-A, 
Trent 1000-AE, Trent 1000-C, Trent 1000-CE, Trent 1000-D, Trent 1000-E, 
Trent 1000-G, and Trent 1000-H engines. This proposed AD was prompted 
by reports of cracking and separation of certain low-pressure turbine 
(LPT) stage 1 blade assemblies. This proposed AD would require initial 
and repetitive inspections of affected LPT stage 1 blade assemblies for 
cracking or separation and, depending on the results of the 
inspections, reduction of the inspection interval or replacement of the 
LPT stage 1 blade set and disk. This proposed AD would also prohibit 
the installation of an LPT disk or blade set assembly unless it is 
considered a serviceable part, as specified in a European Union 
Aviation Safety Agency (EASA) AD, which is proposed for incorporation 
by reference. The FAA is proposing this AD to address the unsafe 
condition on these products.

DATES: The FAA must receive comments on this NPRM by March 18, 2024.

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-2024-0043; 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 service information identified 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.

FOR FURTHER INFORMATION CONTACT: Sungmo Cho, Aviation Safety Engineer, 
FAA, 2200 South 216th Street, Des Moines, WA 98198; 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-2024-0043; Project Identifier 
MCAI-2023-00985-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, FAA, 2200 South 216th Street, Des 
Moines, WA 98198. 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 2023-0165, dated August 22, 2023 
(EASA AD 2023-0165) (also referred to as the MCAI), to address an 
unsafe condition for all RRD Model Trent 1000-A, Trent 1000-AE, Trent 
1000-C, Trent 1000-CE, Trent 1000-D, Trent 1000-E, Trent 1000-G, and 
Trent 1000-H engines. The MCAI states that manufacturer inspections 
detected cracking and separation of blade pairs in the weld region of 
certain LPT stage 1 blade assemblies. A blade assembly consists of a 
pair of blades welded together at the outer shroud. There are 85 LPT 
stage 1 blade assemblies in one set. Such cracking and separation could 
cause failure of affected parts and damage to the LPT module.
    You may examine the MCAI in the AD docket at regulations.gov under 
Docket No. FAA-2024-0043.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed EASA AD 2023-0165, which specifies procedures for 
inspection of affected LPT stage 1 blade assembly outer shrouds and 
replacement of the LPT stage 1 blade set and disk. EASA AD 2023-0165 
also specifies a reduction of the repetitive inspection intervals if 
cracking or separation is detected and meets certain criteria. 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 ADDRESSES.

[[Page 6451]]

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

Proposed AD Requirements in This NPRM

    This proposed AD would require accomplishing the actions specified 
in EASA AD 2023-0165 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 EASA AD 2023-0165 by reference 
in the FAA final rule. This proposed AD would, therefore, require 
compliance with EASA AD 2023-0165 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 within the 
compliance times,'' compliance with this AD requirement is not limited 
to the section titled ``Required Action(s) and Compliance Time(s)'' in 
EASA AD 2023-0165. Service information required by the EASA AD for 
compliance will be available at regulations.gov under Docket No. FAA-
2024-0043 after the FAA final rule is published.

Costs of Compliance

    The FAA estimates that this AD, if adopted as proposed, would 
affect 28 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 LPT stage 1 blade outer       4 work-hours x $85 per               $0             $340           $9,520
 shroud.                               hour = $340.
----------------------------------------------------------------------------------------------------------------

    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 
engines that might need these replacements.

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                     Cost per
                    Action                                 Labor cost               Parts cost        product
----------------------------------------------------------------------------------------------------------------
Replace LPT stage 1 blade set.................  10 work-hours x $85 per hour =          $466,480        $467,330
                                                 $850.
Replace LPT stage 1 disk......................  10 work-hours x $85 per hour =           256,908         257,758
                                                 $850.
----------------------------------------------------------------------------------------------------------------

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:

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:

[[Page 6452]]

Rolls-Royce Deutschland Ltd & Co KG: Docket No. FAA-2024-0043; 
Project Identifier MCAI-2023-00985-E.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by March 18, 2024.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Rolls-Royce Deutschland Ltd & Co KG Model 
Trent 1000; Rolls-Royce Deutschland Ltd & Co KG Trent 1000-A, Trent 
1000-AE, Trent 1000-C, Trent 1000-CE, Trent 1000-D, Trent 1000-E, 
Trent 1000-G, and Trent 1000-H engines.

(d) Subject

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

(e) Unsafe Condition

    This AD was prompted by reports of cracking and separation of 
certain low-pressure turbine (LPT) stage 1 blade assemblies. The FAA 
is issuing this AD to prevent failure of the LPT stage 1 blades. The 
unsafe condition, if not addressed, could result in high energy 
debris release, 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, European Union Aviation Safety Agency AD 
2023-0165, dated August 22, 2023 (EASA AD 2023-0165).

(h) Exceptions to EASA AD 2023-0165

    (1) Where EASA AD 2023-0165 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 
2023-0165.
    (3) Where the service information referenced in EASA AD 2023-
0165 specifies discarding the removed LP turbine stage 1 blade set, 
this AD requires removing the affected part from service.
    (4) Where the service information referenced in EASA AD 2023-
0165 specifies to quarantine the removed LP turbine stage 1 rotor 
disk, this AD requires removing the affected part from service.

(i) No Reporting Requirement

    Although the service information referenced in EASA AD 2023-0165 
specifies to submit certain information to the manufacturer, this AD 
does not include that requirement.

(j) Alternative Methods of Compliance (AMOCs)

    (1) 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: [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, FAA, 2200 South 216th Street, Des Moines, WA 98198; 
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 this AD specifies otherwise.
    (i) European Union Aviation Safety Agency (EASA) AD 2023-0165, 
dated August 22, 2023.
    (ii) [Reserved]
    (3) For EASA AD 2023-0165, 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 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 Administration (NARA). For information on the availability 
of this material at NARA, visit www.archives.gov/federal-register/cfr/ibr-locations or email [email protected].

    Issued on January 26, 2024.
Michael Linegang,
Acting Director, Compliance & Airworthiness Division, Aircraft 
Certification Service.
[FR Doc. 2024-01976 Filed 1-31-24; 8:45 am]
BILLING CODE 4910-13-P
```