Document ID: FAA-2021-0662-0008
Agency: faa
Document Type: Rule
Title: Airworthiness Directives: Rolls-Royce Deutschland Ltd and Co KG (Type Certificate previously held by Rolls-Royce plc) Turbofan Engines
Posted Date: 2022-02-22T05:00Z

[Federal Register Volume 87, Number 35 (Tuesday, February 22, 2022)]
[Rules and Regulations]
[Pages 9425-9427]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-03638]

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 Rules and Regulations
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  Federal Register / Vol. 87, No. 35 / Tuesday, February 22, 2022 / 
Rules and Regulations  

[[Page 9425]]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-0662; Project Identifier MCAI-2021-00031-E; 
Amendment 39-21943; AD 2022-04-02]
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.

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

SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
certain Rolls-Royce Deutschland Ltd & Co KG (RRD) Trent 1000 model 
turbofan engines. 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. This AD requires manual deactivation of the 
modulated air system (MAS) control valves. The FAA is issuing this AD 
to address the unsafe condition on these products.

DATES: This AD is effective March 29, 2022.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of March 29, 
2022.

ADDRESSES: For service information identified in this final rule, 
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: 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 (817) 222-5110. It is also available at https://www.regulations.gov by searching for and locating Docket No. FAA-2021-
0662.

Examining the AD Docket

    You may examine the AD docket at https://www.regulations.gov 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 final rule, the 
mandatory continuing airworthiness information (MCAI), any comments 
received, and other information. The address for Docket Operations is 
U.S. Department of Transportation, Docket Operations, M-30, West 
Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, 
Washington, DC 20590.

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: [email protected].

SUPPLEMENTARY INFORMATION:

Background

    The FAA issued a supplemental notice of proposed rulemaking (SNPRM) 
to amend 14 CFR part 39 by adding an AD that would apply to certain 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. 
The SNPRM published in the Federal Register on November 05, 2021 (86 FR 
61083). The SNPRM was prompted by the notice of proposed rulemaking 
(NPRM) being placed in incorrect Docket No. FAA-2021-0637 instead of 
Docket No. FAA-2021-0662, which caused some commenters to experience 
difficulty commenting on the NPRM. In the SNPRM, the FAA proposed to 
require manual deactivation of the MAS control valves. The FAA is 
issuing this AD to address the unsafe condition on these products.
    The European Union Aviation Safety Agency (EASA), which is the 
Technical Agent for the Member States of the European Union, 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 
docket at https://www.regulations.gov by searching for and locating 
Docket No. FAA-2021-0662.

Discussion of Final Airworthiness Directive

Comments

    The FAA received a comment from one commenter, Roll-Royce plc (RR). 
The following presents the comment received on the SNPRM and the FAA's 
response to the comment.

Request To Consider Improved Solution as a Terminating Action

    RR stated that it has no objections to the SNPRM as written but 
requested that the FAA consider an improved solution that is being 
developed by RR as a terminating action for this AD. RR noted that the 
improved solution would permanently deactivate the MAS system without 
initiating engine indicating and crew alerting system (EICAS) messages. 
RR reasoned that deactivation of the MAS was introduced as an immediate 
containment action; however, this solution produces spurious EICAS 
messages, indicating a malfunction in

[[Page 9426]]

the MAS system. As a result, operators are instructed not to follow the 
minimum equipment list instructions and limitations.
    The FAA will consider the improved solution as a possible 
terminating action and may consider future rulemaking once the improved 
solution becomes available. The FAA did not change this AD as a result 
of this comment.

Conclusion

    The FAA reviewed the relevant data, considered the comment 
received, and determined that air safety and the public interest 
require adopting this AD as proposed. Accordingly, the FAA is issuing 
this AD to address the unsafe condition on these products. This AD is 
adopted as proposed in the 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.

Costs of Compliance

    The FAA estimates that this AD affects 4 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
----------------------------------------------------------------------------------------------------------------
Deactivate the MAS control valves.....  2 work-hours x $85 per                $0            $170            $680
                                         hour = $170.
----------------------------------------------------------------------------------------------------------------

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 this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Will not affect intrastate aviation in Alaska, and
    (3) Will 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 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:

2022-04-02 Rolls-Royce Deutschland Ltd & Co KG (Type Certificate 
previously held by Rolls-Royce plc): Amendment 39-21943; Docket No. 
FAA-2021-0662; Project Identifier MCAI-2021-00031-E.

(a) Effective Date

    This airworthiness directive (AD) is effective March 29, 2022.

(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

[[Page 9427]]

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] TR22FE22.000

(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 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.

(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: [email protected].
    (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 https://www.regulations.gov 
by searching for and locating Docket No. FAA-2021-0662.

(j) 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 Alert Non-Modification Service Bulletin Trent 
1000 75-AK642, Initial Issue, dated November 30, 2020.
    (ii) [Reserved]
    (3) For Rolls-Royce 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: https://www.rolls-royce.com/contact-us.aspx.
    (4) You may view this service information at 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: https://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued on February 3, 2022.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2022-03638 Filed 2-18-22; 8:45 am]
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