AD 2021-08-01

Recurring final rule

Airworthiness Directives; Rolls-Royce Deutschland Ltd & Co KG (Type Certificate Previously Held by Rolls-Royce plc) Turbofan Engines

AD Number
2021-08-01
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Docket No. FAA-2021-0200
FR Citation
86 FR 19777
Technical illustration of an aircraft turbine engine assembly
Problem area Engine

Applicability

TypeManufacturerModelDetails
engine Rolls-Royce Deutschland Ltd & Co KG RB211 Trent 768-60 Airworthiness Directives; Rolls-Royce Deutschland Ltd & Co KG (Type Certificate Previously Held by Rolls-Royce plc) Turbofan Engines
engine Rolls-Royce Deutschland Ltd & Co KG RB211 Trent 772-60 Airworthiness Directives; Rolls-Royce Deutschland Ltd & Co KG (Type Certificate Previously Held by Rolls-Royce plc) Turbofan Engines
engine Rolls-Royce Deutschland Ltd & Co KG RB211 Trent 772B-60 Airworthiness Directives; Rolls-Royce Deutschland Ltd & Co KG (Type Certificate Previously Held by Rolls-Royce plc) Turbofan Engines

Unsafe Condition

certain low-pressure compressor (LPC) blades may have been subjected to maintenance actions that caused damage, making the affected blades more susceptible to cracking.

AI-generated summary from the source AD text. Verify against the official source before acting.

Required Actions

initial and repetitive inspections of the blade root of certain LPC blades and re-lubrication of the LPC blades and LPC disk. Depending on the results of the inspection, this AD requires replacement of the LPC blades. As a mandatory terminating action, at the next engine shop visit, this AD requires restoration of the LPC blades to a serviceable condition and examination and re-lubrication of the LPC disk.

AI-generated summary from the source AD text. Verify against the official source before acting.

Compliance Time

Before further flight

AI-generated summary from the source AD text. Verify against the official source before acting.

Affected Aircraft

RRD RB211 Trent 768-60, RB211 Trent 772-60, and RB211 Trent 772B-60 model turbofan engines.

AI-generated summary from the source AD text. Verify against the official source before acting.

Federal Register Abstract

The FAA is adopting a new airworthiness directive (AD) for certain Rolls-Royce Deutschland Ltd & Co KG (RRD) RB211 Trent 768-60, RB211 Trent 772-60, and RB211 Trent 772B-60 model turbofan engines. This AD was prompted by maintenance that resulted in damage to certain low-pressure compressor (LPC) blades, resulting in increased susceptibility to cracking in the LPC blade root. This AD requires initial and repetitive inspections of the blade root of certain LPC blades and re-lubrication of the LPC blades and LPC disk. Depending on the results of the inspections, this AD requires replacement of the LPC blades. As a terminating action to the inspection and re-lubrication requirements, this AD requires restoration of the LPC blade as well as examination and re-lubrication of the LPC disk. The FAA is issuing this AD to address the unsafe condition on these products.

Applicability Source Text

Show captured applicability text from the source AD
(c) Applicability

    This AD applies to Rolls-Royce Deutschland Ltd & Co KG (Type 
Certificate previously held by Rolls-Royce plc) RB211 Trent 768-60, 
RB211 Trent 772-60, and RB211 Trent 772B-60 model turbofan engines 
equipped with:
    (1) Low-pressure compressor (LPC) blade, with part number (P/N) 
FW23741 or P/N KH23403, and a serial number (S/N) listed in Appendix 
1 of Rolls-Royce (RR) Trent 700 Series Propulsion Systems Alert Non-
Modification Service Bulletin (NMSB) RB.211-72-AK492, Revision 1, 
dated November 30, 2020 (NMSB RB.211-72-AK492), installed; or
    (2) LPC disk, with P/N FK22541, P/N FW16259 or P/N KH20338, and 
an S/N listed in Appendix 2 of NMSB RB.211-72-AK492.

Document Text

Show stored source text (verify against official source)
[Federal Register Volume 86, Number 71 (Thursday, April 15, 2021)]
[Rules and Regulations]
[Pages 19777-19780]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2021-07567]



========================================================================
Rules and Regulations
                                                Federal Register
________________________________________________________________________

This section of the FEDERAL REGISTER contains regulatory documents 
having general applicability and legal effect, most of which are keyed 
to and codified in the Code of Federal Regulations, which is published 
under 50 titles pursuant to 44 U.S.C. 1510.

The Code of Federal Regulations is sold by the Superintendent of Documents. 

========================================================================


Federal Register / Vol. 86, No. 71 / Thursday, April 15, 2021 / Rules 
and Regulations

[[Page 19777]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-0200; Project Identifier MCAI-2020-01520-E; 
Amendment 39-21495; AD 2021-08-01]
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: Final rule; request for comments.

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

SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
certain Rolls-Royce Deutschland Ltd & Co KG (RRD) RB211 Trent 768-60, 
RB211 Trent 772-60, and RB211 Trent 772B-60 model turbofan engines. 
This AD was prompted by maintenance that resulted in damage to certain 
low-pressure compressor (LPC) blades, resulting in increased 
susceptibility to cracking in the LPC blade root. This AD requires 
initial and repetitive inspections of the blade root of certain LPC 
blades and re-lubrication of the LPC blades and LPC disk. Depending on 
the results of the inspections, this AD requires replacement of the LPC 
blades. As a terminating action to the inspection and re-lubrication 
requirements, this AD requires restoration of the LPC blade as well as 
examination and re-lubrication of the LPC disk. The FAA is issuing this 
AD to address the unsafe condition on these products.

DATES: This AD is effective April 30, 2021.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in this AD as of April 30, 
2021.
    The FAA must receive comments on this AD by June 1, 2021.

ADDRESSES: You may send comments, using the procedures found in 14 CFR 
11.43 and 11.45, by any of the following methods:
    <bullet> Federal eRulemaking Portal: Go to <a href="https://www.regulations.gov">https://www.regulations.gov</a>. Follow the instructions for submitting comments.
    <bullet> Fax: (202) 493-2251.
    <bullet> 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.
    <bullet> 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 final rule, contact 
Rolls-Royce plc, P.O. Box 31, Derby, DE24 8BJ, United Kingdom; phone: 
+44 (0)1332 242424; website: <a href="https://www.rolls-royce.com/contact-us.aspx">https://www.rolls-royce.com/contact-us.aspx</a>. 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. It is 
also available at <a href="https://www.regulations.gov">https://www.regulations.gov</a> by searching for and 
locating Docket No. FAA-2021-0200.

Examining the AD Docket

    You may examine the AD docket at <a href="https://www.regulations.gov">https://www.regulations.gov</a> by 
searching for and locating Docket No. FAA-2021-0200; 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 street address for the 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: 
<a href="/cdn-cgi/l/email-protection#a0cbc5d6c9ce8ecd8ec3ccc1d2cbe0c6c1c18ec7cfd6"><span class="__cf_email__" data-cfemail="345f51425d5a1a591a575855465f745255551a535b42">[email&#160;protected]</span></a>.

SUPPLEMENTARY INFORMATION:

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 2020-0253, dated November 12, 2020, to address an unsafe 
condition for the specified products. The MCAI states:

    In-service experience has shown that certain LP compressor 
blades installed on Trent 700 engines may have been subjected to 
maintenance actions that caused damage, making the affected blades 
more susceptible to cracking.
    This condition, if not detected and corrected, could lead to 
blade or disc failure and consequent engine in-flight shut-down, 
possibly resulting in reduced control of the aeroplane.
    To address this potential unsafe condition, Rolls-Royce issued 
the inspection NMSB to provide inspection instructions. Rolls-Royce 
also issued the restoration NMSB to provide in-shop restoration 
instructions.
    For the reasons described above, this [EASA] AD requires 
repetitive on-wing ultra-sonic (US) inspections of the blade roots 
of the affected blades, subsequent re-lubrication of the affected 
blades and discs and, depending on findings, accomplishment of 
applicable corrective action(s). This [EASA] AD also requires in-
shop restoration of the affected blades and discs to a serviceable 
condition, which constitutes terminating action for the repetitive 
US inspections and re-lubrications as required by this [EASA] AD.

    You may obtain further information by examining the MCAI in the AD 
docket at <a href="https://www.regulations.gov">https://www.regulations.gov</a> by searching for and locating 
Docket No. FAA-2021-0200.

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. The FAA is issuing this AD because the 
agency evaluated all the relevant information provided by EASA and has 
determined that the unsafe condition described previously is likely to 
exist or develop in other products of the same type design.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Rolls-Royce (RR) Trent 700 Series Propulsion 
Systems Alert Non-Modification Service Bulletin (NMSB) RB.211-72-AK492, 
Revision 1, dated November 30, 2020. This service information specifies 
procedures for performing initial and repetitive ultrasonic inspections 
of LPC blade roots, and re-lubrication of LPC blades and disks.
    The FAA also reviewed RR Trent 700 Series Propulsion Systems Alert 
NMSB RB.211-72-AK522, Revision 1, dated

[[Page 19778]]

November 30, 2020. This service information specifies procedures for 
inspecting LPC blades, applying high intensity shot peening to the 
blade roots to arrest any cracks, inspecting the LPC disk to determine 
serviceability, and re-lubrication procedures.
    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.

AD Requirements

    This AD requires initial and repetitive inspections of the blade 
root of certain LPC blades and re-lubrication of the LPC blades and LPC 
disk. Depending on the results of the inspection, this AD requires 
replacement of the LPC blades. As a mandatory terminating action, at 
the next engine shop visit, this AD requires restoration of the LPC 
blades to a serviceable condition and examination and re-lubrication of 
the LPC disk.

Differences Between the AD and MCAI or Service Information

    EASA AD 2020-0253, dated November 12, 2020, includes RRD RB211 
Trent 772C-60 model turbofan engines in its Applicability section. This 
model engine is not included in the Applicability of this AD because it 
has not been type certificated in the United States.

Justification for Immediate Adoption and Determination of the Effective 
Date

    Section 553(b)(3)(B) of the Administrative Procedure Act (APA) (5 
U.S.C. 551 et seq.) authorizes agencies to dispense with notice and 
comment procedures for rules when the agency, for ``good cause,'' finds 
that those procedures are ``impracticable, unnecessary, or contrary to 
the public interest.'' Under this section, an agency, upon finding good 
cause, may issue a final rule without providing notice and seeking 
comment prior to issuance. Further, section 553(d) of the APA 
authorizes agencies to make rules effective in less than thirty days, 
upon a finding of good cause.
    The FAA has found the risk to the flying public justifies waiving 
notice and comment prior to adoption of this rule because no domestic 
operators use this product. It is unlikely that the FAA will receive 
any adverse comments or useful information about this AD from any U.S. 
operator. Accordingly, notice and opportunity for prior public comment 
are unnecessary, pursuant to 5 U.S.C. 553(b)(3)(B). In addition, for 
the foregoing reason(s), the FAA finds that good cause exists pursuant 
to 5 U.S.C. 553(d) for making this amendment effective in less than 30 
days.

Comments Invited

    The FAA invites you to send any written data, views, or arguments 
about this final rule. Send your comments to an address listed under 
ADDRESSES. Include ``Docket No. FAA-2021-0200 and Project Identifier 
MCAI-2020-01520-E'' at the beginning of your comments. The most helpful 
comments reference a specific portion of the final rule, 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 final rule 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 
<a href="https://www.regulations.gov">https://www.regulations.gov</a>, including any personal information you 
provide. The agency will also post a report summarizing each 
substantive verbal contact received about this final rule.

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 AD 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 AD, 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 AD. Submissions containing CBI should be sent to Kevin 
M. 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.

Regulatory Flexibility Act

    The requirements of the Regulatory Flexibility Act (RFA) do not 
apply when an agency finds good cause pursuant to 5 U.S.C. 553 to adopt 
a rule without prior notice and comment. Because FAA has determined 
that it has good cause to adopt this rule without prior notice and 
comment, RFA analysis is not required.

Costs of Compliance

    The FAA estimates that this AD affects 0 engines installed on 
airplanes of U.S. registry.
    The FAA estimates the following costs to comply with this AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                     Cost per      Cost on U.S.
                Action                         Labor cost           Parts cost        product        operators
----------------------------------------------------------------------------------------------------------------
Inspect LPC blades and re-lubricate     32 work-hours x $85 per               $0          $2,720              $0
 LPC blade and LPC disk.                 hour = $2,720.
Restore LPC blades, examine and re-     128 work-hours x $85 per               0          10,880               0
 lubricate LPC disk.                     hour = $10,880.
----------------------------------------------------------------------------------------------------------------

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

[[Page 19779]]



                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                     Cost per
                    Action                                Labor cost               Parts cost        product
----------------------------------------------------------------------------------------------------------------
Replace LPC blade............................  .25 work-hours x $85 per hour =        $116,000      $116,021.25
                                                $21.25.
----------------------------------------------------------------------------------------------------------------

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

    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, and
    (2) Will not affect intrastate aviation in Alaska.

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

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:

2021-08-01 Rolls-Royce Deutschland Ltd & Co KG (Type Certificate 
previously held by Rolls-Royce plc): Amendment 39-21495; Docket No. 
FAA-2021-0200; Project Identifier MCAI-2020-01520-E.

(a) Effective Date

    This airworthiness directive (AD) is effective April 30, 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) RB211 Trent 768-60, 
RB211 Trent 772-60, and RB211 Trent 772B-60 model turbofan engines 
equipped with:
    (1) Low-pressure compressor (LPC) blade, with part number (P/N) 
FW23741 or P/N KH23403, and a serial number (S/N) listed in Appendix 
1 of Rolls-Royce (RR) Trent 700 Series Propulsion Systems Alert Non-
Modification Service Bulletin (NMSB) RB.211-72-AK492, Revision 1, 
dated November 30, 2020 (NMSB RB.211-72-AK492), installed; or
    (2) LPC disk, with P/N FK22541, P/N FW16259 or P/N KH20338, and 
an S/N listed in Appendix 2 of NMSB RB.211-72-AK492.

(d) Subject

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

(e) Unsafe Condition

    This AD was prompted by maintenance that resulted in damage to 
certain LPC blades, resulting in increased susceptibility to 
cracking in the blade root. The FAA is issuing this AD to prevent 
failure of the LPC blade and the LPC disk. The unsafe condition, if 
not addressed, could result in engine in-flight shut-down and 
reduced control of the airplane.

(f) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

(g) Required Actions

    (1) Within 200 engine flight cycles (FCs) after the effective 
date of this AD, perform an initial on-wing ultrasonic inspection of 
the blade root of each LPC blade using the Accomplishment 
Instructions, paragraph 3.A.(3)(a) through (c) of NMSB RB.211-72-
AK492.
    (2) Within 200 engine FCs after the effective date of this AD, 
re-lubricate each LPC blade and LPC disk using the Accomplishment 
Instructions, paragraph 3.A.(4) of NMSB RB.211-72-AK492.
    (3) Repeat the inspection of each LPC blade and the re-
lubrication of each LPC blade and LPC disk required by paragraphs 
(g)(1) and (2) of this AD at intervals not to exceed 350 engine FCs 
since the last inspection and re-lubrication.
    (4) If, during any inspection required by paragraph (g)(1) or 
(3) of this AD, an LPC blade is found with unacceptable indications 
as specified in Appendix 4, paragraph 3 of NMSB RB.211-72-AK492, 
before next flight, remove and replace the LPC blade with a part 
eligible for installation.

(h) Mandatory Terminating Action

    As a mandatory terminating action to the inspections and re-
lubrications required by paragraphs (g)(1) through (3) of this AD, 
at the next engine shop visit after the effective date of this AD, 
restore the LPC blades to a serviceable condition and examine and 
re-lubricate the LPC disk using the Accomplishment Instructions, 
paragraph 3.A or 3.B of RR Trent 700 Alert NMSB RB.211-72-AK522, 
Revision 1, dated November 30, 2020.

(i) Definitions

    (1) For the purposes 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 purposes of this AD, a part eligible for 
installation is an LPC blade, with:
    (i) A P/N FW23741 or P/N KH23403, with an S/N listed in Appendix 
1 of RR Trent 700 Series Propulsion Systems Alert NMSB RB.211-72-
AK492, that has passed the inspections required by paragraph (g)(1) 
or (3) of this AD, or has zero flight cycles since new; or
    (ii) A P/N FW23741 or P/N KH23403, with an S/N that is not 
listed in Appendix 1 of RR Trent 700 Series Propulsion Systems Alert 
NMSB RB.211-72-AK492.

(j) Credit for Previous Actions

    (1) You may take credit for the initial inspections and re-
lubrications required by paragraphs (g)(1) and (2) of this AD if you 
performed these actions before the effective date of this AD using 
RR Trent 700 Series Propulsion Systems Alert NMSB RB.211-72-AK492, 
Initial Issue, dated October 2, 2020.
    (2) You may also take credit for the restoration of the LPC 
blades to a serviceable condition and examination and re-lubrication 
of the LPC disk required by paragraph (h) of this AD if you 
performed these actions before the effective date of this AD using 
RR Trent 700 Series Propulsion Systems Alert NMSB

[[Page 19780]]

RB.211-72-AK522, Initial Issue, dated October 2, 2020.

(k) No Reporting Requirements

    The reporting requirements specified in Appendix 4, paragraph 3 
of NMSB RB.211-72-AK492 are not required by this AD.

(l) 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 
ECO Branch, send it to the attention of the person identified in 
Related Information. You may email your request to: <a href="/cdn-cgi/l/email-protection#a0e1eee58de1e48de1edefe3e0c6c1c18ec7cfd6"><span class="__cf_email__" data-cfemail="3d7c7378107c79107c70727e7d5b5c5c135a524b">[email&#160;protected]</span></a>.
    (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.

(m) Related Information

    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: <a href="/cdn-cgi/l/email-protection#0e656b7867602063206d626f7c654e686f6f20696178"><span class="__cf_email__" data-cfemail="402b2536292e6e2d6e232c21322b002621216e272f36">[email&#160;protected]</span></a>.

(n) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference (IBR) 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) Rolls-Royce (RR) Trent 700 Series Propulsion Systems Alert 
Non-Modification Service Bulletin (NMSB) RB.211-72-AK492, Revision 
1, dated November 30, 2020.
    (ii) RR Trent 700 Series Propulsion Systems Alert NMSB RB.211-
72-AK522, Revision 1, dated November 30, 2020.
    (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: <a href="https://www.rolls-royce.com/contact-us.aspx">https://www.rolls-royce.com/contact-us.aspx</a>.
    (4) 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.
    (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: <a href="/cdn-cgi/l/email-protection#4f292a2b3d2a2861232a282e230f212e3d2e61282039"><span class="__cf_email__" data-cfemail="4f292a2b3d2a2861232a282e230f212e3d2e61282039">[email&#160;protected]</span></a>, or go to: <a href="https://www.archives.gov/federal-register/cfr/ibr-locations.html">https://www.archives.gov/federal-register/cfr/ibr-locations.html</a>.

    Issued on April 8, 2021.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2021-07567 Filed 4-14-21; 8:45 am]
BILLING CODE 4910-13-P

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