2022-04276. 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:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to adopt a new airworthiness directive (AD) for all Rolls-Royce Deutschland Ltd. & Co KG (RRD) Trent 7000-72 and Trent 7000-72C model turbofan engines. This proposed AD was prompted by in-service experience showing that certain high-pressure turbine (HPT) blades may prematurely deteriorate to an unacceptable condition when managed in accordance with the inspection intervals in the Time Limits Manual (TLM). This proposed AD would require initial and repetitive on-wing borescope inspections (BSIs) of the HPT blades to detect axial cracking and, depending on the results of the inspections, replacement of the HPT blade set, as specified in a European Union Aviation Safety Agency (EASA) AD, which is proposed for incorporation by reference (IBR). This proposed AD would also require replacement of the HPT blade set before exceeding a specified number of flight cycles. 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 April 15, 2022.

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: [phone].

• 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 material that is proposed for IBR in this AD, contact EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; phone: [phone]; email: [e-mail]. You may find this material on the EASA website at https://ad.easa.europa.eu. For Rolls-Royce service information identified in this NPRM, contact Rolls-Royce plc, Corporate Communications, P.O. Box 31, Derby, DE24 8BJ, United Kingdom; phone: [phone]; fax: [phone]; website: https://www.rolls-royce.com/​contact-us.aspx. You may view this material 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 [phone]. It is also available at https://www.regulations.gov by searching for and locating Docket No. FAA-2022-0150. For the material identified in this AD that is not incorporated by reference, contact Rolls-Royce plc, Corporate Communications, P.O. Box 31, Derby, DE24 8BJ, United Kingdom; phone: [phone]; fax: [phone]; website: https://www.rolls-royce.com/​contact-us.aspx.

Examining the AD Docket

You may examine the AD docket at https://www.regulations.gov by searching for and locating Docket No. FAA-2022-0150; 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 EASA AD, any comments received, and other information. The street address for Docket Operations is listed above.

FOR FURTHER INFORMATION CONTACT:

Nicholas Paine, Aviation Safety Engineer, ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803; phone: [phone]; email: [e-mail].

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-2022-0150; Project Identifier MCAI-2021-00839-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 Nicholas Paine, Aviation Safety Engineer, ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803. Any commentary that the FAA receives that is not specifically designated as CBI will be placed in the public docket for this rulemaking.

Background

EASA, which is the Technical Agent for the Member States of the European Union, has issued EASA AD 2021-0169, dated July 19, 2021 (EASA AD 2021-0169), to address an unsafe condition for all RRD Trent 7000-72 and Trent 7000-72C model turbofan engines.

This proposed AD was prompted by in-service experience showing that certain HPT blades may prematurely deteriorate to an unacceptable condition when managed in accordance with the inspection intervals in the TLM. The manufacturer has issued Rolls-Royce (RR) Alert Non-Modification Service Bulletin (NMSB) Trent 1000 72-AK449, Revision 2, dated July 5, 2021 (the Alert NMSB) specifying procedures for performing initial and repetitive on-wing BSIs of the HPT blades to detect axial cracking. The Alert NMSB also specifies procedures for removing the engine from service to replace the HPT blade set before exceeding a specified number of flight cycles. The compliance time for the initial and repetitive BSIs of the HPT blades proposed by this AD meet the TLM inspection intervals for HPT blade, part number KH64485. The FAA is proposing this AD to prevent failure of the HPT blades. This condition, if not addressed, could result in failure of the engine, in-flight shutdown, and loss of the airplane. See EASA AD 2021-0169 for additional background information.

FAA's Determination

This product has been approved by the aviation authority of another country, and is approved for operation in the United States. Pursuant to the FAA's bilateral agreement with the State of Design Authority, the FAA has been notified about the unsafe condition described in the EASA AD. 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 EASA AD 2021-0169. EASA AD 2021-0169 specifies instructions for performing initial and repetitive on-wing BSIs of the HPT blades to detect axial cracking and, depending on the results of the inspections, removal from service of the engine for in-shop replacement of the HPT blade set. EASA AD 2021-0169 also specifies instructions for replacing HPT blades with a new HPT blade set before exceeding a specified number of flight cycles.

This material is reasonably available because the interested parties have access to it through their normal course of business or by the means identified in ADDRESSES .

Other Related Service Information

The FAA reviewed RR Alert NMSB Trent 1000 72-AK449, Revision 2, dated July 5, 2021. This Alert NMSB specifies procedures for performing initial and repetitive on-wing BSIs of the HPT blades to detect axial cracking. The Alert NMSB also specifies procedures for removing the engine to replace the HPT blade set before exceeding a specified number of flight cycles.

Proposed AD Requirements in This NPRM

This proposed AD would require accomplishing the actions specified in EASA AD 2021-0169, described previously, as incorporated by reference, except for any differences identified as exceptions in the regulatory text of this proposed AD and except as discussed under “Differences Between this Proposed AD and the EASA AD.”

Explanation of Required Compliance Information

In the FAA's ongoing efforts to improve the efficiency of the AD process, the FAA developed a process to use some civil aviation authority (CAA) ADs as the primary source of information for compliance with requirements for corresponding FAA ADs. The FAA has since coordinated with other manufacturers and CAAs to use this process. As a result, the FAA proposes to incorporate by reference EASA AD 2021-0169 in the FAA final rule. This proposed AD would, therefore, require compliance with EASA AD 2021-0169 in its entirety through that incorporation, except for any differences identified as exceptions in the regulatory text of this proposed AD. Using common terms that are the same as the heading of a particular section in EASA AD 2021-0169 does not mean that operators need comply only with that section. For example, where the AD requirement refers to “all required actions and compliance times,” compliance with this AD requirement is not limited to the section titled “Required Action(s) and Compliance Time(s)” in EASA AD 2021-0169. Service information specified by EASA AD 2021-0169 for compliance will be available at https://www.regulations.gov by searching for and locating Docket No. FAA-2022-0150 after the FAA final rule is published.

Differences Between This Proposed AD and the EASA AD

Where EASA AD 2021-0169 requires compliance from its effective date, this proposed AD would require using the effective date of this AD. This proposed AD does not mandate compliance with the “Remarks” section of EASA AD 2021-0169.

Interim Action

The FAA considers that 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 16 engines installed on airplanes of U.S. Registry.

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

Estimated Costs

Action	Labor cost	Parts cost	Cost per product	Cost on U.S. operators
BSI HPT Blades	4 work-hours × $85 per hour = $340	$0	$340	$5,440

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

On-Condition Costs

Action	Labor cost	Parts cost	Cost per product
Replace HPT Blade Set	16 work-hours × $85 per hour = $1,360	$2,001,780	$2,003,140

The FAA has included all known costs in its cost estimate. According to the manufacturer, however, some 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.

§ 39.13

[Amended]

2. The FAA amends § 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-2022-0150; Project Identifier MCAI-2021-00839-E.

(a) Comments Due Date

The FAA must receive comments on this airworthiness directive (AD) by April 15, 2022.

(b) Affected ADs

None.

(c) Applicability

This AD applies to Rolls-Royce Deutschland Ltd. & Co KG (Type Certificate previously held by Rolls-Royce plc) Trent 7000-72 and Trent 7000-72C model turbofan engines.

(d) Subject

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

(e) Unsafe Condition

This AD was prompted by in-service experience showing that certain high-pressure turbine (HPT) blades may prematurely deteriorate to an unacceptable condition when managed in accordance with the inspection intervals defined in the Time Limits Manual. The FAA is issuing this AD to prevent failure of the HPT blades. The unsafe condition, if not addressed, could result in failure of the engine, in-flight shutdown, and loss of the airplane.

(f) Compliance

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

(g) Required Actions

Except as specified in paragraph (h) of this AD: Perform all required actions within the compliance times specified in, and in accordance with, European Union Aviation Safety Agency AD 2021-0169, dated July 19, 2021 (EASA AD 2021-0169).

(h) Exceptions to EASA AD 2021-0169

(1) Where EASA AD 2021-0169 requires compliance from its effective date, this proposed AD would require using the effective date of this AD.

(2) This AD does not require compliance with the “Remarks” section of EASA AD 2021-0169.

(i) 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 (j)(2) of this AD and email to: [e-mail].

(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.

(j) Related Information

(1) For more information about EASA AD 2021-0169, contact EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; phone: [phone]; email: [e-mail]. You may find this material on the EASA website at https://ad.easa.europa.eu. You may view this material 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 [phone]. This material may be found in the AD docket at https://www.regulations.gov by searching for and locating Docket No. FAA-2022-0150.

(2) For more information about this AD, contact Nicholas Paine, Aviation Safety Engineer, ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803; phone: [phone]; email: [e-mail].

(3) For service information identified in this AD, contact Rolls-Royce plc, Corporate Communications, P.O. Box 31, Derby, DE24 8BJ, United Kingdom; phone: [phone]; fax: [phone]; website: https://www.rolls-royce.com/​contact-us.aspx. You may view this material 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 [phone].

Issued on February 24, 2022.

Lance T. Gant,

Director, Compliance & Airworthiness Division, Aircraft Certification Service.