Document ID: FAA-2018-0538-0005
Agency: faa
Document Type: Proposed Rule
Title: Airworthiness Directives: Rolls-Royce plc Turbofan Engines
Posted Date: 2019-11-15T05:00Z

[Federal Register Volume 84, Number 221 (Friday, November 15, 2019)]
[Proposed Rules]
[Pages 62482-62485]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-24594]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2018-0538; Product Identifier 2012-NE-47-AD]
RIN 2120-AA64

Airworthiness Directives; Rolls-Royce plc Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Supplemental notice of proposed rulemaking (SNPRM); reopening 
of comment period.

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SUMMARY: The FAA is revising an earlier proposal for certain Rolls-
Royce plc (RR) RB211 Trent 768-60, 772-60, and 772B-60 model turbofan 
engines. This action revises the notice of proposed rulemaking (NPRM) 
by modifying the inspection threshold for ultrasonic inspections (UIs) 
of the affected low-pressure (LP) compressor blades for both standard 
operations and non-standard operations (NSO). This action also revises 
the service information references. The FAA is proposing this 
airworthiness directive (AD) to address the unsafe condition on these 
products. Since these actions would impose an additional burden over 
those in the NPRM, the FAA is reopening the comment period to allow the 
public the chance to comment on these changes.

DATES: The comment period for the NPRM published in the Federal 
Register on August 14, 2018 (83 FR 40161), is reopened.
    The FAA must receive comments on this SNPRM by December 30, 2019.

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 SNPRM, contact Rolls-
Royce plc, P.O. Box 31, Derby, DE24 8BJ, United Kingdom; phone: 44 
(0)1332 242424; fax: 44 (0)1332 249936; email: https://www.rolls-royce.com/contact/civil_team.jsp. You may view this service information 
at the FAA, Engine and Propeller Standards 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 on the internet at https://www.regulations.gov by searching for and locating Docket No. FAA-2018-
0538; 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), 
the regulatory evaluation, any comments received, and other 
information. The street address for Docket Operations is listed above. 
Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Stephen Elwin, Aerospace Engineer, ECO 
Branch, FAA, 1200 District Avenue, Burlington, MA 01803; phone: 781-
238-7236; fax: 781-238-7199; email: stephen.l.elwin@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 the ADDRESSES section. Include ``Docket No. FAA-2018-0538; 
Product Identifier 2012-NE-47-AD'' at the beginning of your comments. 
The FAA specifically invites comments on the overall regulatory, 
economic, environmental, and energy aspects of this SNPRM. The FAA will 
consider all comments received by the closing date and may amend this 
SNPRM because of those comments.

[[Page 62483]]

    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 SNPRM.

Discussion

    The FAA issued an NPRM to amend 14 CFR part 39 by superseding AD 
2017-03-02, Amendment 39-18793 (82 FR 10701, February 15, 2017), (``AD 
2017-03-02'') that would apply to certain RR RB211 Trent 768-60, 772-
60, and 772B-60 model turbofan engines. AD 2017-03-02 resulted from 
revised service information to reduce the inspection threshold of the 
UI for the LP compressor blades. The NPRM published in the Federal 
Register on August 14, 2018 (83 FR 40161). The NPRM was prompted by LP 
compressor blade partial airfoil release events. The NPRM proposed to 
require initial and repetitive UIs of the affected LP compressor blade 
and replacement of the LP compressor blade with a part eligible for 
installation if the LP compressor blade fails an inspection.
    The European Union Aviation Safety Agency (EASA), which is the 
Technical Agent for the Member States of the European Community, has 
issued EASA AD 2018-0188R1, dated September 5, 2018 (referred to after 
this as ``the MCAI''), to address the unsafe condition on these 
products. The MCAI states:

    Occurrences have been reported of LP compressor partial aerofoil 
blade release events on RR Trent 700 engines. While primary 
containment of the released sections was achieved in each case, some 
of the releases did exhibit secondary effects that are considered to 
present a potential hazard.
    This condition, if not detected and corrected, could lead to LP 
compressor blade release with possible consequent loss of the engine 
nose cowl, under cowl fires and forward projection of secondary 
debris, possibly resulting in damage to the aeroplane and/or injury 
to persons on the ground.
    To address this potential unsafe condition, RR published NMSB 
RB.211-72-G872, providing inspection instructions and, consequently, 
EASA issued AD 2012-0247 to require a one-time inspection of the 
higher life LP compressor blades. After identification of a 
population of these LP compressor blades that were incorrectly 
inspected, RR issued NMSB RB.211-72-H311 and, consequently, EASA 
issued AD 2013-0060, retaining the requirements of EASA AD 2012-
0247, which was superseded, to require a one-time re-inspection of 
the affected blades.
    After that AD was issued, to mitigate the risk of further 
partial LP compressor blade release events, RR issued NMSB RB.211-
72-AH465, providing instructions for ultrasonic inspection of the 
affected parts to detect sub-surface anomalies in the aerofoil. 
Consequently, EASA issued AD 2014-0031, superseding [EASA] AD 2013-
0060, to require repetitive inspections of all affected LP 
compressor blades and, depending on findings, replacement. 
Thereafter, EASA issued AD 2016-0141, retaining the requirements of 
[EASA] AD 2014-0031, which was superseded, to reduce inspection 
threshold (RR Alert NMSB RB.211-72-AH465 Revision 2). Prompted by 
further analysis, EASA issued AD 2017-0241, retaining the 
requirements of EASA AD 2016-0141, which was superseded, further 
reducing the inspection threshold and interval (RR Alert NMSB 
RB.211-72-AH465 Revision 4).
    Since EASA AD 2017-0241 was issued, RR issued the NMSB to 
distinguish between standard operations and NSO and to determine the 
applicable inspection threshold and interval. The flight cycles (FC) 
accumulated by operators conducting NSO have to be calculated using 
the beta factor shown in Table of the NMSB. The NMSB also 
introduces, for engines that have accumulated more than 600 FC or 
standard duty cycles (SDC, for engines used in NSO), a closing date 
by which these have to be inspected at least once.
    For the reason described above, this [EASA] AD retains the 
requirements of EASA AD 2017-0241, which is superseded, and requires 
implementation of the changes introduced.

    You may obtain further information by examining the MCAI in the AD 
docket on the internet at https://www.regulations.gov by searching for 
and locating Docket No. FAA-2018-0538.

Actions Since the NPRM Was Issued

    Since the FAA issued the NPRM, the manufacturer determined the need 
to modify the inspection threshold for UIs and to distinguish between 
operators conducting standard operations and NSO. The manufacturer also 
determined the need to require inspection of engines that have 
accumulated greater than 600 flight cycles (FCs) or standard duty 
cycles (SDCs) for engines used in NSO.
    Also, since the FAA issued the NPRM, EASA issued EASA AD 2018-
0188R1, dated September 5, 2018, which requires UIs of each affected LP 
compressor blade within the compliance time specified in the 
Accomplishment Instructions, paragraph 3, of RR Alert Non-Modification 
Service Bulletin (NMSB) RB.211-72-AH465, Revision 5, dated July 26, 
2018 (``the NMSB''). The FAA also determined the need to revise the 
references to the service information in this AD because, since the 
publication of the NPRM, RR published the NMSB.

Comments

    The FAA gave the public the opportunity to comment on the NPRM. The 
following presents the comments received on the NPRM and the FAA's 
response to each comment.

Request To Update Service Information

    A commenter requested that the FAA update all service information 
references from RR Alert NMSB RB.211-72-AH465, Revision 4, to Revision 
5. The commenter indicated that updated service information contains 
all the inspection compliance time and requirements as Revision 4, but 
Revision 5 also addresses NSO.
    The FAA agrees to reference the latest revision of the service 
information in this proposed AD.

Support for the AD

    The Air Line Pilots Association International supported the NPRM as 
written.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed RR Alert NMSB RB.211-72-AH465, Revision 5, dated 
July 26, 2018. The NMSB describes procedures for performing a UI of the 
LP compressor blades. 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 the ADDRESSES section.

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 proposing this AD because it 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. Certain changes described above 
expand the scope of the NPRM. As a result, the FAA has determined that 
it is necessary to reopen the comment period to provide additional 
opportunity for the public to comment on this SNPRM.

Proposed Requirements of This SNPRM

    This SNPRM would require initial and repetitive UIs of the affected 
LP compressor blades and, depending on the results, their replacement 
with a part eligible for installation.

Costs of Compliance

    The FAA estimates that this proposed AD affects 56 engines 
installed on airplanes of U.S. registry.

[[Page 62484]]

    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 LP compressor blade...........  44 work-hours x $85 per               $0          $3,740        $209,440
                                         hour = $3,740.
----------------------------------------------------------------------------------------------------------------

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

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                     Cost per
                    Action                                 Labor cost               Parts cost        product
----------------------------------------------------------------------------------------------------------------
Replace LP compressor blade (one blade per 77   6 work-hours x $85 per hour =           $103,000        $103,510
 engine sets).                                   $510.
----------------------------------------------------------------------------------------------------------------

    According to the manufacturer, some of the costs of this proposed 
AD may be covered under warranty, thereby reducing the cost impact on 
affected individuals. The FAA does not control warranty coverage for 
affected individuals. As a result, the FAA has included all costs in 
our cost estimate.

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.
    This AD is issued in accordance with authority delegated by the 
Executive Director, Aircraft Certification Service, as authorized by 
FAA Order 8000.51C. In accordance with that order, issuance of ADs is 
normally a function of the Compliance and Airworthiness Division, but 
during this transition period, the Executive Director has delegated the 
authority to issue ADs applicable to engines, propellers, and 
associated appliances to the Manager, Engine and Propeller Standards 
Branch, Policy and Innovation Division.

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) 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 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 (AD):

Rolls-Royce plc: Docket No. FAA-2018-0538; Product Identifier 2012-
NE-47-AD.

(a) Comments Due Date

    The FAA must receive comments by December 30, 2019.

(b) Affected ADs

    This AD replaces AD 2017-03-02, Amendment 39-18793 (82 FR 10701, 
February 15, 2017).

 (c) Applicability

    This AD applies to Rolls-Royce plc (RR) RB211 Trent 768-60, 772-
60, and 772B-60 turbofan engines, with low-pressure (LP) compressor 
blade, part number (P/N) FK23411, FK25441, FK25968, FW11901, 
FW15393, FW23643, FW23741, FW23744, KH23403, or KH23404, installed.

(d) Subject

    Joint Aircraft System Component (JASC) Code 7230, Turbine Engine 
Compressor Section.

(e) Unsafe Condition

    This AD was prompted by LP compressor blade partial airfoil 
release events. While released sections were contained in each case, 
projection of secondary debris and effects could present a potential 
hazard. The FAA is issuing this AD to prevent LP compressor blade 
airfoil separation. The unsafe condition, if not addressed, could 
result in 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) Within the compliance time specified in Figure 1 to 
paragraph (g)(1) of this AD and

[[Page 62485]]

thereafter, at intervals not to exceed 1,200 flight cycles (FCs) or 
Standard Duty Cycle (SDCs) for Non-Standard Operations (NSO), as 
applicable, since the last ultrasonic inspection (UI), perform a UI 
of each affected LP compressor blade in accordance with the 
Accomplishment Instructions, paragraph 3, of RR Alert Non-
Modification Service Bulletin (NMSB) RB.211-72-AH465, Revision 5, 
dated July 26, 2018.

    Note 1 to paragraph (g): Paragraph 1.D of Rolls-Royce Alert NMSB 
RB.211-72-AH465, Revision 5, dated July 26, 2018, describes how to 
determine the applicable SDCs. The Time Limits Manual (TLM), 05-00-
01, defines NSO.

[GRAPHIC] [TIFF OMITTED] TP15NO19.580

    (2) If, during any inspection required by paragraph (g)(1) of 
this AD, a LP compressor blade is rejected by the UI, as defined in 
Accomplishment Instructions, paragraph 3, of RR Alert NMSB RB.211-
72-AH465, Revision 5, dated July 26, 2018, before further flight, or 
before returning the LP compressor blade to service, whichever 
occurs first, remove the affected LP compressor blade from service 
and replace with a part eligible for installation.

(h) Installation Prohibition

    After the effective date of this AD, do not install an affected 
LP compressor blade on an engine unless the LP compressor blade 
meets the conditions specified in paragraphs (h)(1) or (2) of this 
AD, as applicable.
    (1) The affected part has not exceeded 1,200 FC or SDCs (for 
NSO) since new, or since inspection in accordance with RR Alert NMSB 
RB.211-72-AH465, Revision 5, dated July 26, 2018, or since an 
inspection as specified in paragraph (k) of this AD, whichever 
occurs later.
    (2) Prior to installation, the affected part has passed an 
ultrasonic inspection in accordance with paragraph (g)(1) of this 
AD.

(i) No Reporting Requirement

    The reporting requirements in the Accomplishment Instructions, 
paragraph 3 of RR Alert NMSB RB.211-72-AH465, Revision 5, dated July 
26, 2018, are not required by this AD.

(j) Credit for Previous Actions

    You may take credit for LP compressor blade UIs required by 
paragraph (g)(1) of this AD, if you performed the UI before the 
effective date of this AD using:
    (1) The instructions referenced in the mandatory inspection 
paragraph of the applicable engine TLM, provided the compliance 
times of this AD are not exceeded; or
    (2) RR NMSB RB.211-72-G702, dated May 23, 2011; RR NMSB RB.211-
72-G872, Revision 2, dated March 8, 2013, or earlier versions; RR 
NMSB RB.211-72-H311, dated March 8, 2013; RR NMSB RB.211-72-AH465, 
Revision 4, dated October 3, 2017, or earlier versions; Engine 
Manual E-Trent-1RR, Task 72-31-11-200-806; or Airbus A330 Aircraft 
Maintenance Manual (AMM) Task 72-31-41-270-801, or AMM Task 72-31-
41-270-802.

(k) 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 (l)(1) of this AD. 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.

(l) Related Information

    (1) For more information about this AD, contact Stephen Elwin, 
Aerospace Engineer, ECO Branch, FAA, 1200 District Avenue, 
Burlington, MA 01803; phone: 781-238-7236; fax: 781-238-7199; email: 
stephen.l.elwin@faa.gov.
    (2) Refer to European Union Aviation Safety Agency (EASA) AD 
2018-0188R1, dated September 5, 2018, for more information. You may 
examine the EASA AD in the AD docket on the internet at https://www.regulations.gov by searching for and locating it in Docket No. 
FAA-2018-0538.
    (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; fax: 44 (0)1332 249936; email: https://www.rolls-royce.com/contact/civil_team.jsp. You may view this 
referenced service information at the FAA, Engine and Propeller 
Standards Branch, 1200 District Avenue, Burlington, MA 01803. For 
information on the availability of this material at the FAA, call 
781-238-7759.

    Issued in Burlington, Massachusetts, on November 6, 2019.
Robert J. Ganley,
Manager, Engine and Propeller Standards Branch, Aircraft Certification 
Service.
[FR Doc. 2019-24594 Filed 11-14-19; 8:45 am]
 BILLING CODE 4910-13-P