2023-14596. Airworthiness Directives; Rolls-Royce Deutschland Ltd & Co KG 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) Model Trent 1000 engines. This AD was prompted by reports of excessive wear on the inner seal fins of certain high-pressure turbine (HPT) triple seals. This AD requires an inspection of the HPT triple seal for excessive wear and, depending on the results of the inspection, replacement of the HPT triple seal and the intermediate-pressure turbine (IPT) disk, as specified in a European Union Aviation Safety Agency (EASA) AD, which is incorporated by reference. The FAA is issuing this AD to address the unsafe condition on these products.

DATES:

This AD is effective August 15, 2023.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of August 15, 2023.

ADDRESSES:

AD Docket: You may examine the AD docket at regulations.gov under Docket No. FAA–2023–0660; 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.

Material Incorporated by Reference:

• For the EASA AD identified in this final rule, contact EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; phone: [phone]; email: [e-mail]; website: easa.europa.eu. You may find this material on the EASA website at ad.easa.europa.eu.

• You may view this EASA AD 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 regulations.gov under Docket No. FAA–2023–0660.

FOR FURTHER INFORMATION CONTACT:

Sungmo Cho, Aviation Safety Engineer, FAA, 2200 South 216th Street, Des Moines, WA 98198; phone: [phone]; email: [e-mail].

SUPPLEMENTARY INFORMATION:

Background

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to certain RRD Model 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 engines. The NPRM published in the Federal Register on April 7, 2023 (88 FR 20782). The NPRM was prompted by EASA AD 2022–0241, dated December 7, 2022, issued by EASA, which is the Technical Agent for the Member States of the European Union (EASA AD 2022–0241) (referred to after this as the MCAI). The MCAI states that occurrences have been reported of finding higher than expected levels of wear on the seal fins of certain HPT triple seals. The secondary air system is affected by the resulting increased turbine cooling air leakage, which changes the air flow around the IPT disk. The Modulated Air System (MAS) was designed to optimize cooling air flow and intended to be active only during cruise conditions, but the design did not account for a high level of seal wear. Rolls-Royce issued Non-Modification Service Bulletin Trent 1000 75–AK642, Initial Issue, dated November 30, 2020, to provide instructions for MAS deactivation, and consequently, EASA published EASA AD 2021–0009, dated January 8, 2021, specifying deactivation of the MAS control valves. Despite this, a significantly worn HPT triple seal under flight conditions, while MAS was activated prior to the above action, could have reduced the safety of flight.

In the NPRM, the FAA proposed to require accomplishing the actions specified in EASA AD 2022–0241 described previously, except for any differences identified as exceptions in the regulatory text of this AD. The FAA is issuing this AD to address the unsafe condition on these products.

You may examine the MCAI in the AD docket at regulations.gov under Docket No. FAA–2023–0660.

Discussion of Final Airworthiness Directive

Comments

The FAA received a comment from one commenter, The Boeing Company (Boeing). Boeing supported the NPRM without change.

Conclusion

These products have been approved by the aviation authority of another country and are approved for operation in the United States. Pursuant to the FAA's bilateral agreement with this State of Design Authority, it has notified the FAA of the unsafe condition described in the MCAI referenced above. The FAA reviewed the relevant data, considered the comment received, and determined that air safety requires adopting the AD as proposed. Accordingly, the FAA is issuing this AD to address the unsafe condition on these products. Except for minor editorial changes, this AD is adopted as proposed in the NPRM.

Related Service Information Under 1 CFR Part 51

The FAA reviewed EASA AD 2022–0241. EASA AD 2022–0241 specifies procedures for inspecting the HPT triple seal for excessive wear and, depending on the results of the inspection, replacing the HPT triple seal and the IPT 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 .

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

Action	Labor cost	Parts cost	Cost per product	Cost on U.S. operators
Inspect HPT triple seal	1 work-hour × $85 per hour = $85	$0	$85	$340

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

On-Condition Costs

Action	Labor cost	Parts cost	Cost per product
Replace HPT triple seal and IPT disk	4 work-hours × $85 per hour = $340	$737,832	$738,172

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 that 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

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:

2023–12–16 Rolls-Royce Deutschland Ltd & Co KG: Amendment 39–22474; Docket No. FAA–2023–0660; Project Identifier MCAI–2022–01561–E.

(a) Effective Date

This airworthiness directive (AD) is effective August 15, 2023.

(b) Affected ADs

None.

(c) Applicability

This AD applies to certain Rolls-Royce Deutschland Ltd & Co KG (RRD) Model 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 engines, as identified in European Union Aviation Safety Agency (EASA) AD 2022–0241, dated December 7, 2022 (EASA AD 2022–0241).

(d) Subject

Joint Aircraft System Component (JASC) Code 7240, Turbine Engine Combustion Section.

(e) Unsafe Condition

This AD was prompted by reports of excessive wear on the inner seal fins of certain high-pressure turbine (HPT) triple seals. The FAA is issuing this AD to prevent excessive wear on the inner seal fins of certain HPT triple seals. The unsafe condition, if not addressed, could lead to a temperature increase at the intermediate-pressure turbine (IPT) disk rim, possibly resulting in IPT disk failure and high energy debris release, with consequent damage to the airplane and reduced control of the airplane.

(f) Compliance

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

(g) Required Actions

Except as specified in paragraphs (h) and (i) of this AD: Perform all required actions within the compliance times specified in, and in accordance with, EASA AD 2022–0241.

(h) Exceptions to EASA AD 2022–0241

(1) Where EASA AD 2022–0241 refers to its effective date, this AD requires using the effective date of this AD.

(2) This AD does not adopt the Remarks paragraph of EASA AD 2022–0241.

(i) No Reporting Requirement

Although EASA AD 2022–0241 specifies to submit inspection results to the manufacturer, this AD does not include that requirement.

(j) Alternative Methods of Compliance (AMOCs)

(1) The Manager, AIR–520, Continued Operational Safety 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 branch office, send it to the attention of the person identified in paragraph (k) 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.

(k) Additional Information

For more information about this AD, contact Sungmo Cho, Aviation Safety Engineer, FAA, 2200 South 216th Street, Des Moines, WA 98198; phone: [phone]; email: [e-mail].

(l) Material Incorporated by Reference

(1) The Director of the Federal Register approved the incorporation by reference 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) European Union Aviation Safety Agency AD 2022–0241, dated December 7, 2022.

(ii) [Reserved]

(3) For EASA AD 2022–0241, contact EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; phone: [phone]; email: [e-mail]; website: easa.europa.eu. You may find this material on the EASA website at ad.easa.europa.eu.

(4) 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. This material may be found in the AD docket at regulations.gov by searching for and locating Docket No. FAA–2023–0660.

(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: [e-mail], or go to: www.archives.gov/​federal-register/​cfr/​ibr-locations.html.

Issued on June 13, 2023.

Michael Linegang,

Acting Director, Compliance & Airworthiness Division, Aircraft Certification Service.