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###### Department of Transportation

###### Federal Aviation Administration

          - 14 CFR Part 39
          - [Docket No. FAA-2023-1813; Project Identifier MCAI-2023-00980-R; Amendment 39-22540; AD 2023-17-51]
          - RIN 2120-AA64

# AGENCY:

Federal Aviation Administration (FAA), DOT.

# ACTION:

Final rule; request for comments.

# SUMMARY:

The FAA is adopting a new airworthiness directive (AD) for all Bell Textron Canada Limited Model 407 helicopters. The FAA previously sent this AD as an emergency AD to all known U.S. owners and operators of these helicopters. This AD was prompted by a report of a disbonded area in a tail rotor (T/R) blade. This AD requires determining if an affected T/R blade is installed, inspecting each of those T/R blades and, depending on the results, replacing the T/R blade as specified in a Transport Canada emergency AD, which is incorporated by reference. This AD also limits the installation of T/R blades to certain T/R blades. The FAA is issuing this AD to address the unsafe condition on these products.

# DATES:

This AD is effective September 21, 2023. Emergency AD 2023-17-51, issued on August 18, 2023, which contained the requirements of this amendment, was effective with actual notice.

The Director of the Federal Register approved the incorporation by reference of a certain publication identified in this AD as of September 21, 2023.

The FAA must receive comments on this AD by October 23, 2023.

# 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                          regulations.gov . Follow the instructions for submitting comments.                    
      -  Fax:                          (202) 493-2251.                    
      -  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.                    

*AD Docket:*                         You may examine the AD docket at                         *regulations.gov*                         under Docket No. FAA-2023-1813; 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 Transport Canada emergency AD, any comments received, and other information. The street address for Docket Operations is listed above.                    

*Material Incorporated by Reference:*
      - For Transport Canada material that is incorporated by reference in this final rule, contact Transport Canada, Transport Canada National Aircraft Certification, 159 Cleopatra Drive, Nepean, Ontario, K1A 0N5, CANADA; phone 888-663-3639; email TC.AirworthinessDirectives-Consignesdenavigabilite.TC@tc.gc.ca;                          internet                          tc.canada.ca/en/aviation.                          You may find the Transport Canada material                                ( print page 60884)                              on the Transport Canada website at                          tc.canada.ca/en/aviation. 
      - 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 at regulations.gov                          under Docket No. FAA-2023-1813.                    

*Other Related Service Information:*                         For Bell service information identified in this final rule, contact Bell Textron Canada Limited, 12,800 Rue de l'Avenir, Mirabel, Quebec J7J 1R4, Canada; phone 1-450-437-2862 or 1-800-363-8023; fax 1-450-433-0272; email                         *productsupport@bellflight.com;*                         or at                         *bellflight.com/support/contact-support.*                         You may also view this service information at the FAA contact information under                         *Material Incorporated by Reference*                         above.                    

# FOR FURTHER INFORMATION CONTACT:

                        Dan McCully, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone (404) 474-5548; email                         *william.mccully@faa.gov*.                    

# SUPPLEMENTARY INFORMATION:

## Comments Invited

                    The FAA invites you to send any written data, views, or arguments about this final rule. Send your comments to an address listed under                     **ADDRESSES**                    . Include “Docket No. FAA-2023-1813; Project Identifier MCAI-2023-00980-R” at the beginning of your comments. The most helpful comments reference a specific portion of the final rule, 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 final rule 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                     *regulations.gov*, including any personal information you provide. The agency will also post a report summarizing each substantive verbal contact received about this final rule.                

## 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 AD 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 AD, 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 AD. Submissions containing CBI should be sent to Dan McCully, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone (404) 474-5548; email                     *william.mccully@faa.gov.*                     Any commentary that the FAA receives which is not specifically designated as CBI will be placed in the public docket for this rulemaking.                

## Background

The FAA issued Emergency AD 2023-17-51, dated August 18, 2023 (the emergency AD), to address an unsafe condition on Bell Textron Canada Limited Model 407 helicopters. The FAA sent the emergency AD to all known U.S. owners and operators of these helicopters. The emergency AD requires determining if certain serial-numbered T/R blade part number 406-016-100-119 is installed, tap inspecting each affected T/R blade for skin to core voids and, depending on the results, replacing the T/R blade. The emergency AD also limits the installation of T/R blades to affected T/R blades that have passed its required inspection and unaffected T/R blades.

The emergency AD was prompted by Transport Canada Emergency AD CF-2023-63, dated August 17, 2023 (Transport Canada AD CF-2023-63), issued by Transport Canada, which is the aviation authority for Canada, to correct an unsafe condition on certain serial-numbered Bell Textron Canada Limited Model 407 helicopters. Transport Canada AD CF-2023-63 states that an operator identified an abnormal sound in a T/R blade while manually rotating it. A subsequent tap inspection revealed a disbonded area that exceeds allowable limits. According to Transport Canada, an investigation by Bell Textron Canada Limited identified 43 T/R blades that could have missing adhesive between the upper skin and core that was caused during the manufacturing process. This condition, if not addressed, could result in severe vibration, failure of the T/R blade, and subsequent loss of T/R control. The FAA is issuing this AD to address the unsafe condition on these products.

                    You may examine Transport Canada AD CF-2023-63 in the AD docket at                     *regulations.gov*                     under Docket No. FAA-2023-1813.                

## Related Service Information Under 1 CFR Part 51

The FAA reviewed Transport Canada AD CF-2023-63, which requires determining if an affected T/R blade is installed, inspecting each of those T/R blades and, depending on the results, replacing the T/R blade. Transport Canada AD CF-2023-63 also limits installation of T/R blades to serviceable T/R blades, as defined therein.

                    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 also reviewed Bell Alert Service Bulletin 407-23-132, dated August 14, 2023, which identifies affected T/R blade part number 406-016-100-119 serial numbers and specifies procedures for inspecting affected T/R blades for skin to core voids. Depending on the results, this service information specifies procedures for reporting information to Bell Product Support Engineering, returning specified T/R blades to Bell for investigation, and replacing a T/R blade.

## FAA's Determination

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 its emergency AD referenced above. The FAA is issuing this AD after determining that the unsafe condition described previously is likely to exist or develop on other products of the same type design.

## AD Requirements

This AD requires accomplishing the actions specified in Transport Canada AD CF-2023-63, described previously, as incorporated by reference, except for any differences identified as exceptions in the regulatory text of this AD and except as discussed under “Differences Between this AD and the Transport Canada Emergency 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                           ( print page 60885)                        requirements for corresponding FAA ADs. The FAA has been coordinating this process with manufacturers and CAAs. As a result, Transport Canada AD CF-2023-63 is incorporated by reference in this FAA AD. This AD, therefore, requires compliance with Transport Canada AD CF-2023-63 in its entirety through that incorporation, except for any differences identified as exceptions in the regulatory text of this AD. Using common terms that are the same as the heading of a particular section in Transport Canada AD CF-2023-63 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 “Corrective Actions” in Transport Canada AD CF-2023-63.                

## Differences Between This AD and the Transport Canada Emergency AD

Transport Canada AD CF-2023-63 applies to certain serial-numbered Bell Textron Canada Limited Model 407 helicopters, whereas this AD applies to all Bell Textron Canada Limited Model 407 helicopters. Transport Canada AD CF-2023-63 does not clearly specify how to inspect affected T/R blades for skin to core voids, whereas this AD requires tap inspecting each affected T/R blade for skin to core voids.

## Justification for Immediate Adoption and Determination of the Effective Date

                    Section 553(b)(3)(B) of the Administrative Procedure Act (APA) (5 U.S.C. 551*et seq.*) authorizes agencies to dispense with notice and comment procedures for rules when the agency, for “good cause,” finds that those procedures are “impracticable, unnecessary, or contrary to the public interest.” Under this section, an agency, upon finding good cause, may issue a final rule without providing notice and seeking comment prior to issuance. Further, section 553(d) of the APA authorizes agencies to make rules effective in less than thirty days, upon a finding of good cause.                

An unsafe condition exists that required the immediate adoption of Emergency AD 2023-17-51, issued on August 18, 2023, to all known U.S. owners and operators of these helicopters. The FAA found that the risk to the flying public justified waiving notice and comment prior to adoption of this rule because each T/R blade is critical to the control of a helicopter. Debonding of a T/R blade could lead to instantaneous failure before detection. Additionally, affected T/R blades are installed on high usage helicopters, which could increase the likeliness of occurrence of a failure. In light of this, the initial action required by this AD must be accomplished within 10 hours time-in-service or 14 days, whichever occurs first. This compliance time is shorter than the time necessary for the public to comment and for publication of the final rule. These conditions still exist, therefore, notice and opportunity for prior public comment are impracticable and contrary to the public interest pursuant to 5 U.S.C. 553(b)(3)(B).

In addition, the FAA finds that good cause exists pursuant to 5 U.S.C. 553(d) for making this amendment effective in less than 30 days, for the same reasons the FAA found good cause to forego notice and comment.

## Regulatory Flexibility Act

The requirements of the Regulatory Flexibility Act (RFA) do not apply when an agency finds good cause pursuant to 5 U.S.C. 553 to adopt a rule without prior notice and comment. Because FAA has determined that it has good cause to adopt this rule without prior notice and comment, RFA analysis is not required.

## Costs of Compliance

The FAA estimates that this AD affects up to 43 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.

Determining if an affected T/R blade is installed takes about 0.5 work-hour for an estimated cost of $43 per helicopter and up to $1,849 for the U.S. fleet. Tap inspecting an affected T/R blade takes about 1 work-hour for an estimated cost of $85 per T/R blade. If required, replacing a T/R blade takes about 5 work-hours and parts cost about $42,951 for an estimated cost of $43,376 per T/R 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, and

(2) Will not affect intrastate aviation in Alaska.

# 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: 

**2023-17-51 Bell Textron Canada Limited:**                             Amendment 39-22540; Docket No. FAA-2023-1813; Project Identifier MCAI-2023-00980-R.                        

## (a) Effective Date

The FAA issued Emergency Airworthiness Directive (AD) 2023-17-51 on August 18, 2023, directly to affected owners and operators. As a result of such actual notice, the emergency AD was effective for those owners and operators on the date it was provided. This AD contains the same requirements as the emergency AD and, for those who did not receive actual notice, is effective on September 21, 2023.

## (b) Affected ADs

                            None.                                  ( print page 60886)    

## (c) Applicability

This AD applies to Bell Textron Canada Limited Model 407 helicopters, certificated in any category.

## (d) Subject

Joint Aircraft Service Component (JASC) Code: 6410, Tail Rotor Blades.

## (e) Unsafe Condition

This AD was prompted by a report of a disbonded area in a tail rotor (T/R) blade due to missing adhesive between the upper skin and core. The FAA is issuing this AD to detect skin to core voids that exceed allowable limits in affected T/R blades. The unsafe condition, if not addressed, could result in severe vibration, failure of the T/R blade, and subsequent loss of T/R control.

## (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, Transport Canada Emergency AD CF-2023-63, dated August 17, 2023 (Transport Canada AD CF-2023-63).

## (h) Exceptions to Transport Canada AD CF-2023-63

(1) Where Transport Canada AD CF-2023-63 refers to its effective date, this AD requires using the effective date of this AD.

(2) Where Transport Canada AD CF-2023-63 requires compliance in terms of hours air time, this AD requires compliance using hours time-in-service.

(3) Where paragraph A.2. of Transport Canada AD CF-2023-63 requires inspecting an affected T/R blade and the service information referenced in paragraph A.2. of Transport Canada AD CF-2023-63 specifies inspecting an affected T/R blade, this AD requires using a steel tap hammer and tap inspecting each affected T/R blade.

(4) Where the service information referenced in Transport Canada AD CF-2023-63 specifies returning parts to the manufacturer, this AD does not include that requirement.

## (i) No Reporting Requirement

Although the service information referenced in Transport Canada AD CF-2023-63 specifies to submit certain information to the manufacturer, this AD does not include that requirement.

## (j) Special Flight Permits

A special flight permit may be issued in accordance with 14 CFR 21.197 and 21.199 to operate the helicopter to a location where the tap inspection can be performed, provided no passengers are onboard.

## (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 International Validation Branch, mail it to the address identified in paragraph (l) 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

                            For more information about this AD, contact Dan McCully, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone (404) 474-5548; email                             *william.mccully@faa.gov*.                        

## (m) 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) Transport Canada Emergency AD CF-2023-63, dated August 17, 2023.

(ii) [Reserved]

                            (3) For Transport Canada Emergency AD CF-2023-63, contact Transport Canada, Transport Canada National Aircraft Certification, 159 Cleopatra Drive, Nepean, Ontario, K1A 0N5, CANADA; phone 888-663-3639; email                             *TC.AirworthinessDirectives-Consignesdenavigabilite.TC@tc.gc.ca;*                             internet                             *tc.canada.ca/en/aviation.*                             You may find the Transport Canada material on the Transport Canada website at                             *tc.canada.ca/en/aviation.*

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

Issued on August 25, 2023.

Victor Wicklund,

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

[FR Doc. 2023-19324 Filed 9-1-23; 4:15 pm]

BILLING CODE 4910-13-P