Proposed Rule2021-24056
Airworthiness Directives; Rolls-Royce Deutschland Ltd & Co KG (Type Certificate Previously Held by Rolls-Royce plc) Turbofan Engines
Primary source
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Published
November 5, 2021
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA is revising a notice of proposed rulemaking (NPRM) that applied to certain Rolls-Royce Deutschland Ltd & Co KG (RRD) Trent 1000 model turbofan engines. This action revises the NPRM by reopening the comment period because the NPRM was placed in incorrect Docket No. FAA-2021-0637 instead of Docket No. FAA-2021-0662. The FAA is proposing this airworthiness directive (AD) to address the unsafe condition on these products. Since commenters experienced difficulties in commenting on the NPRM, the FAA is requesting comments on this SNPRM.
Full Text
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<title>Federal Register, Volume 86 Issue 212 (Friday, November 5, 2021)</title>
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[Federal Register Volume 86, Number 212 (Friday, November 5, 2021)]
[Proposed Rules]
[Pages 61083-61085]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2021-24056]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2021-0662; Project Identifier MCAI-2021-00031-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: Supplemental notice of proposed rulemaking (SNPRM).
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SUMMARY: The FAA is revising a notice of proposed rulemaking (NPRM)
that applied to certain Rolls-Royce Deutschland Ltd & Co KG (RRD) Trent
1000 model turbofan engines. This action revises the NPRM by reopening
the comment period because the NPRM was placed in incorrect Docket No.
FAA-2021-0637 instead of Docket No. FAA-2021-0662. The FAA is proposing
this airworthiness directive (AD) to address the unsafe condition on
these products. Since commenters experienced difficulties in commenting
on the NPRM, the FAA is requesting comments on this SNPRM.
DATES: The FAA must receive comments on this SNPRM by December 20,
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 SNPRM, contact Rolls-
Royce plc, Corporate Communications, P.O. Box 31, Derby, DE24 8BJ,
United Kingdom; phone: +44 (0)1332 242424; fax: +44 (0)1332 249936;
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.
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-2021-0662; 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 SNPRM, 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 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#b3d8d6c5dadd9dde9dd0dfd2c1d8f3d5d2d29dd4dcc5"><span class="__cf_email__" data-cfemail="c5aea0b3acabeba8eba6a9a4b7ae85a3a4a4eba2aab3">[email protected]</span></a>.
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-2021-0662; Project Identifier
MCAI-2021-00031-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
<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 proposed AD.
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 SNPRM 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 SNPRM, 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 SNPRM. 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 FAA issued an NPRM to amend 14 CFR part 39 by adding an AD that
would apply to 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 NPRM published in the Federal
Register on August 13, 2021 (86 FR 44655). The NPRM was prompted by
reports of high levels of wear on the seal fins on a small number of
certain high-pressure turbine triple seals. In the NPRM, the FAA
proposed to require manual deactivation of the modulated air system
(MAS) control valves.
The European Union Aviation Safety Agency (EASA), which is the
Technical Agent for the Member States of the European Community, has
issued EASA AD 2021-0009, dated January 8, 2021 (referred to after this
as ``the MCAI''), to address the unsafe condition on these products.
The MCAI states:
The Modulated Air System (MAS) optimises cooling air, extracted
from the compressor, where full flow is not required at cruise
conditions. It is only active during cruise. Recently, occurrences
have been reported of finding high levels of wear on the seal fins
on a small number of high pressure turbine triple seals, Part Number
FW34485. The effect on the secondary air system was conservatively
assessed due to the resultant increased turbine cooling air leakage,
which changes the cooling flow around the intermediate pressure (IP)
turbine disc.
This condition, if not corrected, could lead to temperature
increase at the IP turbine disc rim when the MAS is active, possibly
resulting in IP 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 has
issued the NMSB, providing instructions to manually `lock-out'
(deactivate) the MAS control valves.
For the reason described above, this [EASA] AD requires to
deactivate the MAS control valves. This [EASA] AD also specifies
that the Master Minimum Equipment List (MMEL) item for `MAS
inoperative', which has a limit of 120 days, does not apply when the
system is manually deactivated.
You may obtain further information by examining the MCAI in the AD
[[Page 61084]]
docket at <a href="https://www.regulations.gov">https://www.regulations.gov</a> by searching for and locating
Docket No. FAA-2021-0662.
Actions Since the NPRM Was Issued
Since the FAA issued the NPRM, the FAA determined the NPRM was
inadvertently placed in incorrect Docket No. FAA-2021-0637 instead of
Docket No. FAA-2021-0662. The FAA received information that the public
had difficulty commenting on the NPRM.
Comments
The FAA received comments on the NPRM from two commenters. The
following presents the comments received on the NPRM and the FAA's
response to each comment.
Request To Revise the Unsafe Condition
The Boeing Company (Boeing) requested the FAA revise paragraph (e),
Unsafe Condition, of the NPRM to accurately reflect the effect of the
AD on the unsafe condition. Boeing suggested revising paragraph (e) to
state ``This AD was prompted by reports of high levels of wear on the
seal fins on a small number of certain high-pressure turbine (HPT)
triple seals. This condition, if not addressed, could lead to
temperature increase at the Intermediate Pressure (IP) turbine disk rim
when the Modulated Air System (MAS) is active during cruise, possibly
resulting in failure of the IP turbine disk, loss of engine thrust
control, and loss of the airplane. The FAA is issuing this AD to
restore cooling airflow to the IP turbine disk rim during cruise by
deactivating MAS.'' Boeing reasoned that the AD action to deactivate
the MAS does not prevent wear on the HPT triple seal fins. Deactivating
the MAS restores cooling airflow to the intermediate-pressure turbine
(IPT) disk rim during cruise.
The FAA updated paragraph (e) of this proposed AD by stating,
``This AD was prompted by reports of high levels of wear on the seal
fins on a small number of certain high-pressure turbine triple seals.
The FAA is issuing this AD to ensure cooling airflow restoration to the
intermediate-pressure turbine (IPT) disk rim during cruise by
deactivating the modulated air system (MAS). The unsafe condition, if
not addressed, could result in a temperature increase at the IPT disk
rim, when the MAS is active during cruise, resulting in failure of the
IPT disk, loss of engine thrust control, and loss of the airplane.''
Request To Correct Part Number Reference
Rolls-Royce notified the FAA that the preamble of the NPRM
incorrectly identifies the HPT triple seal part number (P/N) as FW3448,
whereas the correct identification is FW34485.
The FAA agrees and has revised the Background section of this
proposed AD by correcting the reference to the HPT triple seal P/N from
FW3448 to FW34485.
FAA's Determination
This product has been approved by EASA and is approved for
operation in the United States. Pursuant to the FAA's bilateral
agreement with the European Community, EASA has notified the FAA of the
unsafe condition described in the MCAI and service information. The FAA
is proposing this AD because the agency evaluated all the relevant
information provided by EASA and determined the unsafe condition
described previously is likely to exist or develop in other products of
the same type design. The public had difficulty commenting on the NPRM.
As a result, the FAA has determined that it is necessary to reopen the
comment period to provide opportunity for the public to comment on this
SNPRM.
Related Service Information Under 1 CFR Part 51
The FAA reviewed Rolls-Royce Alert Non-Modification Service
Bulletin Trent 1000 75-AK642, Initial Issue, dated November 30, 2020.
The service information specifies procedures for deactivating the MAS
control valves. 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 Requirements in This SNPRM
This proposed AD would require manual deactivation of the MAS
control valves. Manual deactivation of the MAS control valves changes
the engine to an approved configuration that will produce engine
indicating and crew alerting system (EICAS) status messages that do not
indicate inoperative (failed) equipment. Consequently, when these
messages are displayed, the operator's existing FAA-approved minimum
equipment list (MEL) instructions and limitations, including the 120-
day operation limitation, do not apply.
Interim Action
The FAA considers this proposed AD would be an interim action. If
final action is later identified, the FAA might consider additional
rulemaking.
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
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Cost per Cost on U.S.
Action Labor cost Parts cost product operators
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Deactivate the MAS control valves..... 2 work-hours x $85 per $0 $170 $680
hour = $170.
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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.
[[Page 61085]]
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:
Rolls-Royce Deutschland Ltd & Co KG (Type Certificate previously
held by Rolls-Royce plc): Docket No. FAA-2021-0662; Project
Identifier MCAI-2021-00031-E.
(a) Comments Due Date
The FAA must receive comments on this airworthiness directive
(AD) by December 20, 2021.
(b) Affected ADs
None.
(c) Applicability
This AD applies to Rolls-Royce Deutschland Ltd & Co KG (RRD)
(Type Certificate previously held by Rolls-Royce plc) 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.
(d) Subject
Joint Aircraft System Component (JASC) Code 7250, Turbine
Section.
(e) Unsafe Condition
This AD was prompted by reports of high levels of wear on the
seal fins on a small number of certain high-pressure turbine triple
seals. The FAA is issuing this AD to ensure cooling airflow
restoration to the intermediate-pressure turbine (IPT) disk rim
during cruise by deactivating the modulated air system (MAS). The
unsafe condition, if not addressed, could result in a temperature
increase at the IPT disk rim when the MAS is active during cruise,
resulting in failure of the IPT disk, loss of engine thrust control,
and loss of the airplane.
(f) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(g) Required Actions
Within the compliance time specified in figure 1 to paragraph
(g) of this AD, deactivate the MAS control valves using the
Accomplishment Instructions, paragraphs 3.A.(6) and 3.A.(7), of
Rolls-Royce Alert Non-Modification Service Bulletin Trent 1000 75-
AK642, Initial Issue, dated November 30, 2020.
Note 1 to paragraph (g): Deactivation of the MAS control valves
on an engine required by paragraph (g) of this AD changes the engine
to an approved configuration that will produce engine indicating and
crew alerting system (EICAS) status messages ``ENG MAS VALVE L/R''
and ``ENG MAS SYS TEST L/R.'' Since MAS is purposely disabled after
compliance with paragraph (g) of this AD, these status messages do
not indicate inoperative (failed) equipment and, consequently, the
operator's existing FAA-approved minimum equipment list (MEL)
instructions and limitations, including the 120-day operation
limitation, do not apply.
Note 2 to paragraph (g): Deactivation of the MAS control valves
on an engine as required by paragraph (g) of this AD does not
produce the EICAS status message ``ENG MAS VALVE SENSOR L/R.''
Consequently, when this EICAS message displays, it remains
indicative of inoperative equipment, even if the MAS has been
disabled as required by paragraph (g) of this AD. As a result, the
corresponding MEL instructions and limitations apply whenever the
EICAS status message ``ENG MAS VALVE SENSOR L/R'' is displayed.
[GRAPHIC] [TIFF OMITTED] TP05NO21.033
(h) 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
paragraph (i)(1) of this AD. Information may be emailed to: <a href="/cdn-cgi/l/email-protection#f2b3bcb7dfb3b6dfb3bfbdb1b2949393dc959d84"><span class="__cf_email__" data-cfemail="60212e254d21244d212d2f23200601014e070f16">[email 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.
(i) Related Information
(1) For more information about this AD, contact Kevin 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#127977647b7c3c7f3c717e736079527473733c757d64"><span class="__cf_email__" data-cfemail="e9828c9f8087c784c78a85889b82a98f8888c78e869f">[email protected]</span></a>.
(2) Refer to European Union Aviation Safety Agency (EASA) AD
2021-0009, dated January 8, 2021, for more information. You may
examine the EASA AD in the AD docket at <a href="https://www.regulations.gov">https://www.regulations.gov</a>
by searching for and locating it in Docket No. FAA-2021-0662.
(3) For service information identified in this AD, contact
Rolls-Royce plc, Corporate Communications, P.O. Box 31, Derby, DE24
8BJ, United Kingdom; phone: +44 (0)1332 242424; fax: +44 (0)1332
249936; website: <a href="https://www.rolls-royce.com/contact-us.aspx">https://www.rolls-royce.com/contact-us.aspx</a>. 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 October 29, 2021.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification
Service.
[FR Doc. 2021-24056 Filed 11-4-21; 8:45 am]
BILLING CODE 4910-13-P
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