# AD 2021-21-08: Ice/Rain Protection System Wiring, Tail Rotor Blades

- Type: Airworthiness directive
- Status: Current
- Products: Leonardo AB139 and AW139
- Effective: December 10, 2021
- Published: November 5, 2021, 86 FR 61058–61060
- Issued: October 7, 2021
- Issued as: Final rule
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Rotorcraft
- Amendment: 39-21768
- Docket: FAA-2021-0671 (https://www.regulations.gov/docket/FAA-2021-0671)
- Project: 2019-SW-036-AD
- Registered aircraft: 165 may be affected, by airframe or engine model (OpenAirDocs)
- Official PDF: https://openairdocs.org/files/sha256/93/a6/93a6a087b10a6a3b5c015f8540e6f58b5235daff9749f70d90028fd16986b21e (from https://www.govinfo.gov/content/pkg/FR-2021-11-05/pdf/2021-24153.pdf)
- Federal Register: https://www.federalregister.gov/documents/2021/11/05/2021-24153/airworthiness-directives-leonardo-spa-helicopters
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/FR-ADFRAWD-2021-24153-0000000000.0001
- DRS record last changed: November 21, 2025
- Page: https://openairdocs.org/ad/2021-21-08

## Summary

The FAA is adopting a new airworthiness directive (AD) for certain Leonardo S.p.a. Model AB139 and AW139 helicopters. This AD was prompted by a report of damage (burns) on the tail rotor blades (TRBs). This AD requires an inspection of each TRB for the general condition and any evidence of burns and replacement if necessary, 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.

## The airworthiness directive

1. The authority citation for part 39 continues to read as follows:

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

2021-21-08 Leonardo S.p.a.: Amendment 39-21768; Docket No. FAA-2021-0671; Project Identifier 2019-SW-036-AD.

### (a) Effective Date

This airworthiness directive (AD) is effective December 10, 2021.

### (b) Affected ADs

None.

### (c) Applicability

This AD applies to Leonardo S.p.a. Model AB139 and AW139 helicopters, certificated in any category, as identified in European Union Aviation Safety Agency (EASA) AD 2019-0073, dated March 28, 2019 (EASA AD 2019-0073).

### (d) Subject

Joint Aircraft Service Component (JASC) Codes: 3097, Ice/Rain Protection System Wiring; 6410, Tail Rotor Blades.

### (e) Unsafe Condition

This AD was prompted by a report of damage (burns) on the tail rotor blades (TRBs). The FAA is issuing this AD to address damage (burns) on the TRBs. The unsafe condition, if not addressed, could result in loss of a TRB, possibly resulting in reduced control of the helicopter.

### (f) Compliance

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

### (g) Requirements

Except as specified in paragraph (h) of this AD: Comply with all required actions and compliance times specified in, and in accordance with, EASA AD 2019-0073.

### (h) Exceptions to EASA AD 2019-0073

  (1) Where EASA AD 2019-0073 requires compliance in terms of flight hours, this AD requires using hours time-in-service.

  (2) Where EASA AD 2019-0073 refers to its effective date, this AD requires using the effective date of this AD.

  (3) Where the service information required by EASA AD 2019-0073 specifies returning a part to the manufacturer, this AD does not include that requirement.

  (4) This AD does not require the “Remarks” section of EASA AD 2019-0073.

  (5) Where paragraph (2) of EASA AD 2019-0073 specifies to replace if there are burn signs or other damage, for this AD, other damage is defined as being consistent with wire overheat ( e.g., possible melted or exposed wires).

### (i) No Reporting Requirement

Although the service information referenced in EASA AD 2019-0073 specifies to submit certain information to the manufacturer, this AD does not include that requirement.

### (j) Special Flight Permit

Special flight permits, as described in 14 CFR 21.197 and 21.199, are not allowed.

### (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 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 International Validation Branch, send it to the attention of the person identified in paragraph (l) of this AD. Information may be emailed to: 9-AVS-AIR-730-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

For more information about this AD, contact Jacob Fitch, Aerospace Engineer, COS Program Management Section, Operational Safety Branch, Compliance & Airworthiness Division, FAA, 10101 Hillwood Pkwy., Fort Worth, TX 76177; phone: (817) 222-4130; email: jacob.fitch@faa.gov.

### (m) Material Incorporated by Reference

  (1) The Director of the Federal Register approved the incorporation by reference (IBR) 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 this AD specifies otherwise.

    (i) European Union Aviation Safety Agency (EASA) AD 2019-0073, dated March 28, 2019.

    (ii) [Reserved]

  (3) For EASA AD 2019-0073, contact the EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; phone: +49 221 8999 000; email: ADs@easa.europa.eu; Internet: www.easa.europa.eu. You may find this EASA AD on the EASA website at https://ad.easa.europa.eu.

  (4) You may view this service information 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. This material may be found in the AD docket on the internet at https://www.regulations.gov by searching for and locating Docket No. FAA-2021-0671.

  (5) You may view this material that is incorporated by reference at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, email fedreg.legal@nara.gov, or go to https://www.archives.gov/federal-register/cfr/ibr-locations.html.

## Rule preamble

### Dates

This AD is effective December 10, 2021.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of December 10, 2021.

### Addresses

For material incorporated by reference (IBR) in this AD, contact the EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; phone: +49 221 8999 000; email: ADs@easa.europa.eu; internet: www.easa.europa.eu. You may find this material on the EASA website at https://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. It is also available in the AD docket on the internet at https://www.regulations.gov by searching for and locating Docket No. FAA-2021-0671.

### For further information contact

Jacob Fitch, Aerospace Engineer, COS Program Management Section, Operational Safety Branch, Compliance & Airworthiness Division, FAA, 10101 Hillwood Pkwy., Fort Worth, TX 76177; phone: (817) 222-4130; email: jacob.fitch@faa.gov.

### Background

The EASA, which is the Technical Agent for the Member States of the European Union, has issued EASA AD 2019-0073, dated March 28, 2019 (EASA AD 2019-0073) (also referred to as the Mandatory Continuing Airworthiness Information, or the MCAI), to correct an unsafe condition for Leonardo S.p.a. Model AB139 and AW139 helicopters.

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 by adding an AD that would apply to certain Leonardo S.p.a. Model AB139 and AW139 helicopters. The NPRM published in the Federal Register on August 18, 2021 (86 FR 46162). The NPRM was prompted by a report of damage (burns) on the TRBs. The NPRM proposed to require an inspection of each TRB for the general condition and any evidence of burns and replacement if necessary, as specified in an EASA AD.

The FAA is issuing this AD to address damage (burns) on the TRBs. The unsafe condition, if not addressed, could result in loss of a TRB, possibly resulting in reduced control of the helicopter. See the MCAI for additional background information.

### Comments

The FAA gave the public the opportunity to participate in developing this final rule. The FAA received no comments on the NPRM or on the determination of the cost to the public.

### Conclusion

The FAA reviewed the relevant data and determined that air safety and the public interest require adopting this final rule as proposed, except for minor editorial changes. The FAA has determined that these minor changes:

• Are consistent with the intent that was proposed in the NPRM for addressing the unsafe condition; and

• Do not add any additional burden upon the public than was already proposed in the NPRM.

### Related Service Information Under 1 CFR Part 51

EASA AD 2019-0073 requires an inspection of each TRB for the general condition and any evidence of burns and replacement if necessary. 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 the ADDRESSES section.

### Costs of Compliance

The FAA estimates that this AD, affects 138 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 |
| --- | --- | --- | --- | --- |
| Inspection | 3 work-hours × $85 per hour = $255 (4 blades) | $0 | $255 | $35,190 |

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 |
| --- | --- | --- | --- |
| Replacement (per blade) | 2 work-hours × $85 per hour = $170 | $57,500 per blade | $57,670 per blade. |

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.

### The Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows:

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS R00002RD](https://openairdocs.org/tcds/R00002RD): Leonardo S.p.a.; names 2 of 2 models: AW139, AB139

## Registered aircraft it may apply to (OpenAirDocs)

Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment.

- Aircraft: 165 (165 by airframe model, 0 by engine model)
- Makers: Agustawestland Philadelphia 99, Agusta 22, Agusta Aerospace 21, Leonardo 13, Leonardo Helicopters US 6, Agustawestland 3, Leonardo S P A 1

Models with the most aircraft:

- [Agustawestland Philadelphia AW139](https://openairdocs.org/model/agustawestland-philadelphia-aw139): 99 aircraft (airframe model)
- [Agusta Aerospace AW139](https://openairdocs.org/model/agusta-aerospace-aw139): 21 aircraft (airframe model)
- [Agusta AW139](https://openairdocs.org/model/agusta-aw139): 14 aircraft (airframe model)
- [Leonardo AW139](https://openairdocs.org/model/leonardo-aw139): 13 aircraft (airframe model)
- [Agusta AB139](https://openairdocs.org/model/agusta-ab139): 8 aircraft (airframe model)
- [Leonardo Helicopters US AW139](https://openairdocs.org/model/leonardo-helicopters-us-aw139): 6 aircraft (airframe model)
- [Agustawestland AW139](https://openairdocs.org/model/agustawestland-aw139): 3 aircraft (airframe model)
- [Leonardo S P A AB139](https://openairdocs.org/model/leonardo-s-p-a-ab139): 1 aircraft (airframe model)

All 8 models: https://openairdocs.org/ad/2021-21-08/models.md
Every aircraft: https://openairdocs.org/ad/2021-21-08/aircraft.md

## Related documents

- [Proposed rule FAA-2021-0671](https://openairdocs.org/proposed/FAA-2021-0671): Notice of proposed rulemaking (NPRM), published Aug 18, 2021

Its text cites no advisory circulars or STCs.

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