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###### Department of Transportation

###### Federal Aviation Administration

          - 14 CFR Part 39
          - [Docket No. FAA-2024-0997; Project Identifier MCAI-2022-01306-R; Amendment 39-22832; AD 2024-17-07]
          - RIN 2120-AA64

# AGENCY:

Federal Aviation Administration (FAA), DOT.

# ACTION:

Final rule.

# SUMMARY:

The FAA is adopting a new airworthiness directive (AD) for all Leonardo S.p.a. Model AB139 and AW139 helicopters. This AD was prompted by multiple reports of cracks found on tail rotor (TR) damper bracket assemblies. This AD requires accomplishing repetitive detailed visual inspections (DVIs) of certain part-numbered TR damper bracket assemblies for corrosion and cracks and, depending on the results, taking corrective action. This AD also prohibits installing an affected TR damper bracket assembly unless it is new. These actions are 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 November 12, 2024.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of November 12, 2024.

# ADDRESSES:

*AD Docket:*                         You may examine the AD docket at                         *regulations.gov*                         under Docket No. FAA-2024-0997; 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 EASA material identified in this AD, contact EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; phone +49 221 8999 000; email: ADs@easa.europa.eu;                          internet:                          easa.europa.eu.                          You may find the EASA material on the EASA website at                          ad.easa.europa.eu. 
      - You may view this material at the FAA, Office of the Regional Counsel, Southwest Region, 10101 Hillwood Pkwy., Room 6N-321, Fort Worth, TX 76177. For information on the availability of this material at the FAA, call (817) 222-5110. The EASA material is also available at regulations.gov                          under Docket No. FAA-2024-0997.                    

*Other Related Material:*                         For Leonardo Helicopters material, contact Leonardo S.p.A., Emanuele Bufano, Head of Airworthiness, Viale G. Agusta 520, 21017 C. Costa di Samarate (Va) Italy; phone: (+39) 0331-225074; fax: (+39) 0331-229046; or at                         *customerportal.leonardocompany.com/en-US/.*

# FOR FURTHER INFORMATION CONTACT:

                        Sungmo Cho, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (781) 238-7241; email:                         *Sungmo.D.Cho@faa.gov*.                    

# 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 Leonardo S.p.a. Model AB139 and AW139 helicopters. The NPRM published in the                     **Federal Register**                     on April 10, 2024 (89 FR 25194). The NPRM was prompted by EASA AD 2022-0154, dated August 1, 2022 (EASA AD 2022-0154; also referred to as the MCAI), issued by EASA, which is the Technical Agent for the Member States of the European Union. EASA AD 2022-0154 stated that during scheduled                           ( print page 80996)                        inspections, some TR damper bracket assemblies were found cracked and that subsequent investigation revealed that the cracks originated from the outer edges of the TR damper bracket lug bores and were due to stress corrosion. That condition, if not detected and corrected, could lead to fracture of the affected part (TR damper bracket assembly), TR blade loss, unbalance or damage to the tail or other parts of the helicopter, possibly resulting in failure of the TR damper, and consequent loss of control of the helicopter. Therefore, EASA AD 2022-0154 required repetitive DVIs of the affected part for cracks and corrosion, and, depending on findings, replacing the affected part with a serviceable part.                

After EASA AD 2022-0154 was issued, new occurrences were reported on additional serial-numbered and part-numbered TR damper bracket assemblies that were not included in the initial batch of affected parts and it was determined that additional TR damper bracket assemblies must also be inspected. Consequently, EASA issued EASA AD 2022-0205, dated October 4, 2022 (EASA AD 2022-0205), to retain the requirements of EASA AD 2022-0154, which is superseded, expand the definition of “affected part,” and require the DVIs for all affected parts.

In the NPRM, the FAA proposed to require accomplishing repetitive DVIs of certain part-numbered TR damper bracket assemblies for corrosion and cracks and, depending on the results, taking corrective action. In the NPRM, the FAA also proposed to prohibit installing an affected TR damper bracket assembly unless it is new. The FAA is issuing this AD to address the unsafe condition on these products.

                    You may examine EASA AD 2022-0205 in the AD docket at                     *regulations.gov*                     under Docket No. FAA-2024-0997.                

## Discussion of Final Airworthiness Directive

## Comments

The FAA received a comment from one anonymous commenter. The commenter supported the NPRM without change.

## Conclusion

These products have been approved EASA and are approved for operation in the United States. Pursuant to the FAA's bilateral agreement with the European Union, EASA 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 Material Under 1 CFR Part 51

EASA AD 2022-0205 requires repetitive DVIs of the TR damper bracket assembly for cracks and corrosion. Depending on the results of these inspections, EASA AD 2022-0205 requires removing any corrosion, replacing any cracked part or a part which the corrosion cannot be removed with a serviceable part, and reporting any discrepancies to Leonardo. EASA AD 2022-0205 allows installing an affected part on any helicopter, provided it is a serviceable part, which is an affected part that is new. EASA AD 2022-0205 also allows installing any TR damper bracket assembly that is not an affected part as defined within.

                    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**                     section.                

## Other Related Material

The FAA also reviewed Leonardo Helicopters Alert Service Bulletin No. 139-724, Revision B, dated September 29, 2022. This material specifies procedures for inspecting and if necessary, replacing certain part-numbered and serial-numbered TR damper bracket assemblies.

## Differences Between This AD and EASA AD 2022-0205

EASA AD 2022-0205 requires reporting certain information to Leonardo, whereas this AD does not.

## Costs of Compliance

The FAA estimates that this AD affects 126 helicopters of U.S. registry. Labor rates are estimated at $85 per work-hour. Based on these numbers, the FAA estimates the following costs to comply with this AD.

A DVI of the TR damper bracket assembly takes approximately 1 work-hour for an estimated cost of $85 per helicopter and up to $10,710 for the U.S. fleet, per inspection cycle.

If required, removing corrosion from the TR damper bracket assembly takes approximately 1 work-hour for an estimated cost of $85 per helicopter.

If required, removing a TR damper bracket assembly and replacing it with a serviceable part takes approximately 8 work-hours and parts cost approximately $4,540 for an estimated cost of $5,220 per TR damper bracket assembly.

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

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: 

      ( print page 80997)    Authority:49 U.S.C. 106(g), 40113, 44701.

§ 39.13

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

**2024-17-07 Leonardo S.p.a.:**                             Amendment 39-22832; Docket No. FAA-2024-0997; Project Identifier MCAI-2022-01306-R.                        

## (a) Effective Date

This airworthiness directive (AD) is effective November 12, 2024.

## (b) Affected ADs

None.

## (c) Applicability

This AD applies to Leonardo S.p.a. Model AB139 and AW139 helicopters, certificated in any category.

## (d) Subject

Joint Aircraft System Component (JASC) Code: 6400, Tail Rotor System.

## (e) Unsafe Condition

This AD was prompted by multiple reports of cracks found on tail rotor (TR) damper bracket assemblies. The FAA is issuing this AD to detect and address corrosion or cracks on the TR damper bracket assembly. The unsafe condition, if not addressed, could lead to fracture of the affected part (TR damper bracket assembly), TR blade loss, unbalance or damage to the tail or other parts of the helicopter, possibly resulting in failure of the TR damper, and consequent loss of control of the helicopter.

## (f) Compliance

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

## (g) Requirements

Except as specified in paragraphs (h) and (i) of this AD: Comply with all required actions and compliance times specified in, and in accordance with, European Union Aviation Safety Agency (EASA) AD 2022-0205, dated October 4, 2022 (EASA AD 2022-0205).

## (h) Exceptions to EASA AD 2022-0205

(1) Where EASA AD 2022-0205 requires compliance in terms of flight hours, this AD requires using hours time-in-service.

(2) Where EASA AD 2022-0205 refers to its effective date and August 15, 2022 (the effective date of EASA AD 2022-0154, dated August 1, 2022), this AD requires using the effective date of this AD.

(3) Where paragraph (4) of EASA AD 2022-0205 states to “replace the affected part with a serviceable part in accordance with the instructions of section 3 of the ASB;” for this AD, replace that text with “remove the affected part, as defined in EASA AD 2022-0205, from service and replace it with a serviceable part, as defined in EASA AD 2022-0205, in accordance with the instructions of section 3 of the ASB.”

(4) Where the material referenced in paragraph (4) of EASA AD 2022-0205 specifies to perform detailed visual inspections (DVIs) and “If no cracks are found, but suspected evidences of corrosion signs are found, gently polish the interested area,” for the purposes of this AD, “suspected signs of corrosion” and “suspected evidences of corrosion signs” are signs of discoloration, pitting, flaking, or rust stains.

(5) Where the material referenced in paragraph (4) of EASA AD 2022-0205 specifies to discard certain parts, this AD requires removing those parts from service.

(6) This AD does not require compliance with paragraph (6) of EASA AD 2022-0205.

(7) This AD does not adopt the “Remarks” section of EASA AD 2022-0205.

## (i) No Reporting Requirement

Although the material referenced in EASA AD 2022-0205 specifies to reporting certain information to the manufacturer, this AD does not include that requirement.

## (j) Credit for Previous Actions

This paragraph provides credit for the initial instance of the detailed visual inspections (DVIs) required by paragraph (g) of this AD, for TR damper bracket assemblies identified in Table 1 of EASA AD 2022-0205, if those actions were performed before the effective date of this AD using Leonardo Helicopters Alert Service Bulletin No. 139-724, Revision A, dated September 19, 2022.

## (k) Alternative Methods of Compliance (AMOCs)

                            (1) The Manager, International Validation Branch, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in §  39.19. In accordance with §  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 certification office, send it to the attention of the person identified in paragraph (l)(1) of this AD. If sending information directly to the manager of the International Validation Branch, mail it to the address identified in paragraph (l)(1) of this AD or email to:                             *9-AVS-AIR-730-AMOC@faa.gov.*                             If mailing information, also submit information by email.                        

(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) Additional Information

                            (1) For more information about this AD, contact Sungmo Cho, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (781) 238-7241; email:                             *Sungmo.D.Cho@faa.gov.*

                            (2) For Leonardo Helicopters material identified in this AD that is not incorporated by reference, contact Leonardo S.p.A., Emanuele Bufano, Head of Airworthiness, Viale G. Agusta 520, 21017 C. Costa di Samarate (Va) Italy; phone: (+39) 0331-225074; fax: (+39) 0331-229046; or at                             *customerportal.leonardocompany.com/en-US/.*

## (m) Material Incorporated by Reference

(1) The Director of the Federal Register approved the incorporation by reference of the material listed in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.

(2) You must use this material as applicable to do the actions required by this AD, unless the AD specifies otherwise.

(i) European Union Aviation Safety Agency (EASA) AD 2022-0205, dated October 4, 2022.

(ii) [Reserved]

                            (3) For EASA material identified in this AD, contact EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; phone: +49 221 8999 000; email:                             *ADs@easa.europa.eu;*                             internet:                             *easa.europa.eu.*                             You may find the EASA material on the EASA website at                             *ad.easa.europa.eu.*

(4) You may view this material at the FAA, Office of the Regional Counsel, Southwest Region, 10101 Hillwood Pkwy., Room 6N-321, Fort Worth, TX 76177. For information on the availability of this material at the FAA, call (817) 222-5110.

                            (5) You may view this material at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, visit                             *www.archives.gov/​federal-register/​cfr/​ibr-locations*                             or email                             *fr.inspection@nara.gov.*

Issued on August 22, 2024.

Steven W. Thompson,

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

[FR Doc. 2024-23066 Filed 10-4-24; 8:45 am]

BILLING CODE 4910-13-P