DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2020-1174; Project Identifier MCAI-2019-00135-E]
RIN 2120-AA64

Airworthiness Directives; Rolls-Royce Deutschland Ltd & Co KG
(Type Certificate Previously Held by Rolls-Royce Deutschland GmbH,
Formerly BMW Rolls-Royce GmbH) 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) BR700-710A1-10,
BR700-710A2-20 and BR700-710C4-11 model turbofan engines. This proposed
AD was prompted by an investigation by RRD, which revealed a quality
escape during the high-pressure turbine (HPT) stage 1 disk rim cooling
air hole manufacturing process. This proposed AD would require removing
affected HPT disks from service prior to reaching specified compliance
times or at the next engine shop visit, whichever occurs first. 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 March 8,
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 Deutschland Ltd & Co KG, Eschenweg 11, Dahlewitz 15827, Germany;
phone: +49 0 33 7086 1200; email: rrd.techhelp@rolls-royce.com. 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-2020-1174; 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: Wego Wang, Aviation Safety Engineer,
ECO Branch, FAA, 1200 District Avenue, Burlington MA 01803; phone:
(781) 238-7134; fax: (781) 238-7199; email: wego.wang@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-2020-1174; Project Identifier
MCAI-2019-00135-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 agency 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 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 NPRM. Submissions containing CBI should be sent to Wego
Wang, 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 2019-0299, dated December 10, 2019 (referred to after
this as "the MCAI"), to address the unsafe condition on these
products. The MCAI states:

An occurrence was reported of an HPT stage 1 disc burst on an
industrial gas turbine engine. Subsequent investigation revealed a
quality escape during HPT stage 1 disc rim cooling air hole
manufacturing process. A review revealed that 28 HPT stage 1 discs
were subject to a similar quality escape, two of which have been
recovered and removed from service. The consequence of this
manufacturing error is that the affected parts can no longer safely
reach their Declared Safe Cyclic Life (DSCL).

This condition, if not corrected, may lead to failure of an
affected part, possibly resulting in release of high-energy debris,
with consequent damage to, and/or reduced control of, the aeroplane.
To address this potentially unsafe condition, RRD issued the NMSB,
providing instructions to remove the engine from service for in-shop
replacement of the affected part.

For the reasons described above, this [EASA] AD reduces the DSCL
for the affected parts, requires identification of the affected
parts and removal from service of each affected engine for
replacement of the affected part. This [EASA] AD also prohibits
(re)installation 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-2020-1174.

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 in other
products of the same type design.

Related Service Information Under 1 CFR Part 51

The FAA reviewed RRD Alert Non-Modification Service Bulletin (NMSB)
SB-BR700-72-A900659, Revision 1, dated November 5, 2019 (the NMSB). The
NMSB provides the part numbers and serial numbers for affected HPT
disks, the serial numbers for all engines with an affected HPT disk
installed, and instructions for replacement of the affected HPT 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 replacement of the affected HPT disk
before reaching specified compliance times or at the next engine shop
visit, whichever occurs first.

Costs of Compliance

The FAA estimates that this AD, if adopted as proposed, would
affect 21 engines installed on airplanes of U.S. registry.

The FAA estimates the following costs to comply with this proposed AD:

Estimated Costs

The FAA has included all known costs in its cost estimate.
According to the manufacturer, however, all of the costs of this
proposed AD may be covered under warranty, thereby reducing the cost
impact on affected operators.

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

(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

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]

2. The FAA amends Sec. 39.13 by adding the following new airworthiness
directive: