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###### Department of Transportation

###### Federal Aviation Administration

          - 14 CFR Part 39
          - [Docket No. FAA-2019-0293; Product Identifier 2017-SW-052-AD; Amendment 39-21610; AD 2021-13-05]
          - RIN 2120-AA64

# AGENCY:

Federal Aviation Administration (FAA), DOT.

# ACTION:

Final rule.

# SUMMARY:

The FAA is adopting a new airworthiness directive (AD) for Airbus Helicopters Deutschland GmbH (Airbus Helicopters) Model EC135P1, EC135P2, EC135P2+, EC135P3, EC135T1, EC135T2, EC135T2+, and EC135T3 helicopters. This AD requires modifying the tail rotor (T/R) control installation, a functional test, and corrective actions as necessary. This AD was prompted by cases of insufficient clearance between a certain T/R control bearing connection and the helicopter structure, which were detected on the production line. The FAA is issuing this AD to address the unsafe condition on these products.

# DATES:

This AD is effective August 11, 2021.

The Director of the Federal Register approved the incorporation by reference of a certain document listed in this AD as of August 11, 2021.

# ADDRESSES:

For service information identified in this final rule, contact Airbus Helicopters, 2701 North Forum Drive, Grand Prairie, TX 75052; telephone 972-641-0000 or 800-232-0323; fax 972-641-3775; or at *https://www.airbus.com/​helicopters/​services/​technical-support.html*. You may view the referenced service information at the FAA, Office of the Regional Counsel, Southwest Region, 10101 Hillwood Pkwy., Room 6N-321, Fort Worth, TX 76177. Service information that is incorporated by reference is also available at *https://www.regulations.gov*      ( print page 35600)    by searching for and locating Docket No. FAA-2019-0293. 

## Examining the AD Docket

You may examine the AD docket at *https://www.regulations.gov* by searching for and locating Docket No. FAA-2019-0293; 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 European Aviation Safety Agency (now European Union Aviation Safety Agency) (EASA) AD, any comments received, and other information. The street 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.

# FOR FURTHER INFORMATION CONTACT:

David Hatfield, Aviation Safety Engineer, Aircraft Systems Section, Technical Innovation Policy Branch, FAA, 10101 Hillwood Pkwy., Fort Worth, TX 76177; telephone 817-222-5110; email *david.hatfield@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 Airbus Helicopters Model EC135P1, EC135P2, EC135P2+, EC135P3, EC135T1, EC135T2, EC135T2+, and EC135T3 helicopters with serial number (S/N) up to and including 1254 (except S/N 1235). The NPRM published in the **Federal Register** on April 16, 2021 (86 FR 20089). In the NPRM, the FAA proposed to require modifying the T/R control within 360 hours time-in-service (TIS) by installing a Teflon washer and performing a functional test in accordance with specified portions of Airbus Helicopters Alert Service Bulletin ASB EC135-67A-031, Revision 0, dated March 30, 2017 (ASB EC135-67A-031). Based on the results of the functional test, the NPRM proposed to require making repairs in accordance with FAA-approved procedures. The NPRM was prompted by EASA AD 2017-0147, dated August 10, 2017 (EASA AD 2017-0147), issued by EASA, which is the Technical Agent for the Member States of the European Union, to correct an unsafe condition for Airbus Helicopters Model EC135P1, EC135P2, EC135P2+, EC135P3, EC135T1, EC135T2, EC135T2+, EC135T3, EC635P2+, EC635P3, EC635T1, EC635T2+, and EC635T3 helicopters. EASA advises that several cases of insufficient clearance between a certain T/R bearing connection and the helicopter structure were detected during inspections of helicopters on the production line. EASA states that this condition, if not corrected and in the case of an unglued bearing, could lead to blockage of the pedal controlling the T/R thrust and loss of the T/R control. EASA further advises that this could result in a forced landing with damage to the helicopter and injury to the occupants.

Accordingly, EASA AD 2017-0147 requires modifying the T/R control installation by adding a Teflon washer, which reduces the degree of freedom in case of a drifting bearing at the affected connection. EASA AD 2017-0147 also requires a functional test for clearance, and depending on the results, either accomplishing additional corrective actions or contacting Airbus Helicopters for instructions.

## Comments

The FAA received no comments on the NPRM or on the determination of the costs.

## Conclusion

These helicopters have been approved by 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 about the unsafe condition described in its AD. The FAA reviewed the relevant data and determined that air safety requires adopting this AD as proposed. Accordingly, the FAA is issuing this AD to address the unsafe condition on these helicopters.

## Related Service Information Under 1 CFR Part 51

The FAA reviewed ASB EC135-67A-031 for Airbus Helicopters Model EC135P1, EC135P2, EC135P2+, EC135P3, EC135T1, EC135T2, EC135T2+, EC135T3, EC635P2+, EC635P3, EC635T1, EC635T2+, and EC635T3 helicopters. For S/Ns up to 1254 inclusive, except S/N 1235, this service information specifies retrofitting a Teflon washer on the T/R controls, performing a functional test of the modified T/R control installation to inspect for clearance, and making any necessary adjustments. This service information advises that S/N 1255 and up will have the Teflon washer installed in production.

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 the **ADDRESSES** section.

## Differences Between This AD and the EASA AD

The EASA AD sets compliance times at 12 months, while this AD requires compliance within 360 hours TIS. The EASA AD applies to Airbus Helicopters Model EC635T1, EC635T2+, EC635T3, EC635P2+, and EC635P3 helicopters; this AD does not because these models do not have an FAA type certificate. The EASA AD requires contacting Airbus Helicopters for approved repair procedures; this AD requires a repair using FAA-approved procedures. The EASA AD requires revising the “aircraft maintenance program,” whereas this AD does not because not all U.S. operators are required to have a maintenance program.

## Costs of Compliance

The FAA estimates that this AD affects 331 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.

Modifying the T/R control installation and conducting a functional test takes about 3 work-hours and parts cost about $25 for an estimated cost of $280 per helicopter and $92,680 for the U.S. fleet.

If required, adjusting the clearance takes about 1 work-hour for an estimated cost of $85 per helicopter.

## 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 helicopters 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       ( print page 35601)    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

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

**2021-13-05 Airbus Helicopters Deutschland GmbH:** Amendment 39-21610; Docket No. FAA-2019-0293; Product Identifier 2017-SW-052-AD.

## (a) Effective Date

This airworthiness directive (AD) is effective August 11, 2021.

## (b) Affected ADs

None.

## (c) Applicability

This AD applies to Airbus Helicopters Deutschland GmbH Model EC135P1, EC135P2, EC135P2+, EC135P3, EC135T1, EC135T2, EC135T2+, and EC135T3 helicopters with serial number (S/N) up to and including 1254 (except S/N 1235), certificated in any category.

## (d) Subject

Joint Aircraft Service Component (JASC) Code: 6720, Tail Rotor Control System.

## (e) Unsafe Condition

This AD defines the unsafe condition as interference between the tail rotor (T/R) control bearing connection close-tolerance bolt and the helicopter structure, which could lead to blockage of the pedal controlling the T/R thrust. This condition could result in loss of T/R control, prompting a forced landing.

## (f) Compliance

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

## (g) Required Actions

Within 360 hours time-in-service, modify the T/R control by installing a Teflon washer and perform a functional test of the modification in accordance with the Accomplishment Instructions, paragraphs 3.B.2 through 3.B.4.2., of Airbus Helicopters Alert Service Bulletin ASB EC135-67A-031, Revision 0, dated March 30, 2017. If, during the functional test, the clearance between the end of the close‐tolerance bolt, castellated nut, and the lower stringer is less than 1.0 mm, repair in accordance with FAA-approved procedures.

## (h) 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 (i)(1) 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.

## (i) Related Information

(1) For more information about this AD, contact David Hatfield, Aviation Safety Engineer, Aircraft Systems Section, Technical Innovation Policy Branch, FAA, 10101 Hillwood Pkwy., Fort Worth, TX 76177; telephone 817-222-5110; email *david.hatfield@faa.gov.*

(2) The subject of this AD is addressed in European Aviation Safety Agency (now European Union Aviation Safety Agency) (EASA) AD 2017-0147, dated August 10, 2017. You may view the EASA AD at *https://www.regulations.gov* in Docket No. FAA-2019-0293.

## (j) 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) Airbus Helicopters Alert Service Bulletin ASB EC135-67A-031, Revision 0, dated March 30, 2017.

(ii) [Reserved]

(3) For Airbus Helicopters service information identified in this AD, contact Airbus Helicopters, 2701 North Forum Drive, Grand Prairie, TX 75052; telephone 972-641-0000 or 800-232-0323; fax 972-641-3775; or at *https://www.airbus.com/​helicopters/​services/​technical-support.html.*

(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.

(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: *fedreg.legal@nara.gov,* or go to: *https://www.archives.gov/​federal-register/​cfr/​ibr-locations.html.*

Issued on June 10, 2021.

Lance T. Gant,

Director, Compliance & Airworthiness Division, Aircraft Certification Service.

[FR Doc. 2021-14343 Filed 7-6-21; 8:45 am]

BILLING CODE 4910-13-P