[Federal Register Volume 85, Number 245 (Monday, December 21, 2020)]
[Proposed Rules]
[Pages 82970-82972]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-28042]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2020-1138; Project Identifier MCAI-2020-01258-E]
RIN 2120-AA64


Airworthiness Directives; Rolls-Royce Deutschland Ltd & Co KG 
(Type Certificate Previously Held by Rolls-Royce plc) 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-A2, 
1000-AE2, 1000-C2, 1000-CE2, 1000-D2, 1000-E2, 1000-G2, 1000-H2, 1000-
J2, 1000-K2 and 1000-L2 model turbofan engines. This proposed AD was 
prompted by the manufacturer's analysis which determined that cracks 
may initiate in the front seal fins and cause cracks in the low-
pressure turbine (LPT) disk. This proposed AD would require repetitive 
inspection of the seal fins and, depending on the results of the 
inspection, replacement of the LPT disk before further flight. The FAA 
is proposing this AD to address the unsafe condition on these products.

DATES: The FAA must receive comments on this proposed AD by February 4, 
2021.

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 https://www.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.
    For service information identified in this NPRM, contact Rolls-
Royce plc, P.O. Box 31, Derby, DE24 8BJ, United Kingdom, phone: +44 
(0)1332 242424; website: https://www.rolls-royce.com/contact-us.aspx. 
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 (781) 238-7759.

Examining the AD Docket

    You may examine the AD docket at https://www.regulations.gov by 
searching for and locating Docket No. FAA-2020-1138; 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.

FOR FURTHER INFORMATION CONTACT: Kevin M. Clark, Aviation Safety 
Engineer, ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803; 
phone: (781) 238-7088; fax: (781) 238-7199; email: 
kevin.m.clark@faa.gov.

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-2020-1138; Project Identifier 
MCAI-2020-01258-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 
https://www.regulations.gov, including any personal information you 
provide. The FAA 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

[[Page 82971]]

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 final rule. Submissions containing CBI should be sent to 
Kevin Clark, 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

    The European Union Aviation Safety Agency (EASA), which is the 
Technical Agent for the Member States of the European Community, has 
issued EASA AD 2020-0195, dated September 8, 2020 (referred to after 
this as ``the MCAI''), to address the unsafe condition on these 
products. The MCAI states:

    Analysis of certain LP turbine discs in service has determined 
that, due to rubbing contact with interstage static seals, cracks 
may initiate in the front seal fins which could lead to cracks in 
the disc of the affected parts, as defined in this [EASA] AD.
    This condition, if not detected and corrected, could lead to 
crack propagation, possibly resulting in LP turbine disc failure and 
high-energy debris release, with consequent damage to, and reduced 
control of, the aeroplane.
    To address this potential unsafe condition, Rolls-Royce 
published the NMSB to provide inspection instructions.
    For the reason described above, this [EASA] AD requires 
repetitive ultra-high sensitivity fluorescent penetrant inspections 
of the seal fins of the affected parts and, depending on findings, 
replacement of affected parts.

    You may obtain further information by examining the MCAI in the AD 
docket at https://www.regulations.gov by searching for and locating 
Docket No. FAA-2020-1138.

FAA's Determination

    This product has been approved by EASA and is approved for 
operation in the United States. Pursuant to our bilateral agreement 
with the European Community, EASA has notified us of the unsafe 
condition described in the MCAI and service information referenced 
above. The FAA is issuing this NPRM because the agency evaluated all 
the relevant information provided by EASA and determined the unsafe 
condition described previously is likely to exist or develop on other 
products of the same type design.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Rolls-Royce Non-Modification Service Bulletin 
Trent 1000 72-AK416, dated June 29, 2020 (the NMSB). The NMSB provides 
instructions for inspecting the LPT stage 3 disk and the LPT stage 4 
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.

Proposed AD Requirements in This NPRM

    This proposed AD would require inspection of the seal fins of the 
LPT stage 3 disks and LPT stage 4 disks during each engine shop visit 
after the effective date of this AD and, depending on the results of 
the inspection, replacement of the LPT stage 3 or LPT stage 4 disk 
before further flight.

Costs of Compliance

    The FAA estimates that this AD, if adopted as proposed, would 
affect 26 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 the LPT stage 3 disk and LPT    80 work-hours x $85 per               $0          $6,800        $176,800
 stage 4 disk.                           hour = $6,800.
----------------------------------------------------------------------------------------------------------------

    The FAA estimates the following costs to do any necessary 
replacement that would be required based on the results of the proposed 
inspection. The FAA has no way of determining the number of aircraft 
that might need this replacement.

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                     Cost per
                    Action                                 Labor cost               Parts cost        product
----------------------------------------------------------------------------------------------------------------
Replace LPT stage 3 disk......................  0 work-hours x $85 per hour = $0        $336,158        $336,158
Replace LPT stage 4 disk......................  0 work-hours x $85 per hour = $0         406,345         406,345
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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

[[Page 82972]]

    (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:

Rolls-Royce Deutschland Ltd & Co KG (Type Certificate previously 
held by Rolls-Royce plc): Docket No. FAA-2020-1138; Project 
Identifier MCAI-2020-01258-E.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by February 4, 2021.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Rolls-Royce Deutschland Ltd & Co KG (Type 
Certificate previously held by Rolls-Royce plc) (RRD) Trent 1000-A2, 
1000-AE2, 1000-C2, 1000-CE2, 1000-D2, 1000-E2, 1000-G2, 1000-H2, 
1000-J2, 1000-K2 and 1000-L2 model turbofan engines with a low-
pressure turbine (LPT) stage 3 disk with part number (P/N) KH36323, 
or an LPT stage 4 disk with P/N KH33943, installed.

(d) Subject

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

(e) Unsafe Condition

    This AD was prompted by the manufacturer's analysis of certain 
LPT disks in service. The analysis determined that, due to rubbing 
contact with interstage static seals, cracks may initiate in the 
front seal fins, which could lead to cracks in the LPT stage 3 and 
stage 4 disks. The FAA is issuing this AD to prevent failure of the 
LPT disk. The unsafe condition, if not addressed, could result in 
uncontained LPT disk release, 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

    (1) During each engine shop visit after the effective date of 
this AD, inspect the seal fins of the LPT stage 3 disk and the LPT 
stage 4 disk in accordance with the Accomplishment Instructions, 
paragraphs 3.B and 3.C, of the Rolls-Royce Alert Non-Modification 
Service Bulletin (NMSB) Trent 1000 72-AK416, Initial Issue, dated 
June 29, 2020.
    (i) For an engine that is in an engine shop visit on the 
effective date of this AD, if the LPT stage 3 disk and LPT stage 4 
disk are exposed, perform the inspection before the engine is 
returned to service.
    (ii) [Reserved]
    (2) If, during any inspection required by paragraph (g)(1) of 
this AD, any crack is detected, before further flight, remove the 
affected LPT disk and replace it with a part eligible for 
installation.

(h) Definitions

    (1) For the purpose of this AD, an ``engine shop visit'' is the 
induction of an engine into the shop for maintenance involving the 
separation of pairs of major mating engine flanges, with the 
exception of the separation of engine flanges solely for the purpose 
of transporting the engine without subsequent maintenance.
    (2) For the purpose of this AD, a ``part eligible for 
installation'' is an LPT stage 3 disk or LPT stage 4 disk with zero 
flight cycles since new, or an LPT stage 3 disk or LPT stage 4 disk 
that has passed the inspection required by paragraph (g)(1) of this 
AD.

(i) 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 Related Information. You may email your request to: 
ANE-AD-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.

(j) Related Information

    (1) For more information about this AD, contact Kevin M. Clark, 
Aviation Safety Engineer, ECO Branch, FAA, 1200 District Avenue, 
Burlington, MA 01803; phone: (781) 238-7088; fax: (781) 238-7199; 
email: kevin.m.clark@faa.gov.
    (2) Refer to European Union Aviation Safety Agency (EASA) AD 
2020-0195, dated September 8, 2020, for more information. You may 
examine the EASA AD in the AD docket at https://www.regulations.gov 
by searching for and locating it in Docket No. FAA-2020-1138.
    (3) For service information identified in this AD, contact 
Rolls-Royce plc, P.O. Box 31, Derby, DE24 8BJ, United Kingdom, 
phone: +44 (0)1332 242424; website: https://www.rolls-royce.com/contact-us.aspx. You may view this referenced 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 (781) 238-7759.

    Issued on December 15, 2020.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2020-28042 Filed 12-18-20; 8:45 am]
BILLING CODE 4910-13-P


