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###### Department of Transportation

###### Federal Aviation Administration

          - 14 CFR Part 39
          - [Docket No. FAA-2024-2329; Project Identifier AD-2024-00451-R; Amendment 39-22864; AD 2024-20-05]
          - 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 Columbia Helicopters, Inc., Model 234 helicopters and restricted category Model CH-47D helicopters. This AD was prompted by two reports of a flight control rigid connecting link (link) failure, due to a manufacturing defect.                               ( print page 82497)                            This AD requires removing certain links from service and prohibits installing those links. The FAA is issuing this AD to address the unsafe condition on these products.                    

# DATES:

This AD is effective October 28, 2024.

The FAA must receive comments on this AD by November 25, 2024.

# 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-2024-2329; 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, any comments received, and other information. The street address for Docket Operations is listed above.                    

*Related Material:*                         For Boeing material identified in this AD, contact Billings Flying Service, Inc., 309 Jellison Road, Billings, MT 59101; phone: (406) 252-6937; email:                         *jed@flybfscom.*

# FOR FURTHER INFORMATION CONTACT:

                        David Herron, Aviation Safety Engineer, FAA, 3960 Paramount Boulevard, Lakewood, CA 90712; phone: (206) 231-3544; email:                         *david.herron@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 the                     **ADDRESSES**                     section. Include “Docket No. FAA-2024-2329; Project Identifier AD-2024-00451-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 David Herron, Aviation Safety Engineer, FAA, 3960 Paramount Boulevard, Lakewood, CA 90712; phone: (206) 231-3544; email:                     *david.herron@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 received two reports of a link part number (P/N) 145C3340-10 failure involving a Model CH-47D helicopter. In both reports, it was determined that the failed link was manufactured by Aero Components Inc., which was not an approved supplier for these links. Boeing advised that failure of one link was caused by an eccentricity of the threaded bore in the end of the tube associated with the rod-end installation, which was determined to be a manufacturing defect; this resulted in a thin wall condition on one-side. Failure of the other link showed the same contributor, but on the opposite end of the tube.

Boeing advised some links having P/N 145C3340 have been found to have missing or illegible markings; however, both failed links involve clear Aero Components Inc. CAGE code markings. Columbia Helicopters, Inc., Model 234 helicopters are also affected by the unsafe condition since the affected links may also be installed on that model helicopter.  

This condition, if not addressed, could result in link failure within the flight control system due to fatigue. The FAA is issuing this AD to address the unsafe condition on these products and subsequent immediate loss of control of the helicopter.

## FAA's Determination

The FAA is issuing this AD because the agency determined the unsafe condition described previously is likely to exist or develop in other products of the same type design.

## Related Material

The FAA reviewed Boeing CH-47 Service Bulletin No. 145-67-1047, dated May 22, 2024. This material specifies procedures for inspecting link P/N 145C3340-10 to determine its manufacturing code and, depending on the results, contacting Boeing for additional assistance or replacing the link.

## AD Requirements

This AD requires removing links P/N 145C3340-10 with manufacturing CAGE code 59213 from service and prohibits installing those links on any helicopter.

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

                    Section 553(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 requires the immediate adoption of this AD without providing an opportunity for public comments prior to adoption. The FAA has found that the risk to the flying public justifies forgoing notice and comment prior to adoption of this rule because the affected component is part of an assembly that is critical to the flight control of a helicopter, such that if failure occurs in the affected component subsequent immediate loss of control of a helicopter will occur. As the FAA has no information pertaining to the extent of fatigue of the affected component that may currently exist in helicopters or how quickly the condition may propagate to failure, the actions required by this AD must be accomplished within 5 days. The compliance time in this AD is shorter than the time necessary for the public to comment and for publication of the final                           ( print page 82498)                        rule. Accordingly, notice and opportunity for prior public comment are impracticable and contrary to the public interest pursuant to 5 U.S.C. 553(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 forgo 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 36 helicopters of U.S. registry. Labor costs are estimated at $85 per work-hour. Based on these numbers, the FAA estimates the following costs to comply with this AD.

Replacing a link will take 8 work-hours and parts will cost $1,963 for an estimated cost of $2,643 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 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: 

**2024-20-05 Columbia Helicopters, Inc., and Restricted Category Model CH-47D Helicopters:**                             Amendment 39-22864; Docket No. FAA-2024-2329; Project Identifier AD-2024-00451-R.                        

## (a) Effective Date

This airworthiness directive (AD) is effective October 28, 2024.

## (b) Affected ADs

None.

## (c) Applicability

This AD applies to the helicopters identified in paragraphs (c)(1) and (2) of this AD with a flight control rigid connecting link (link) part number (P/N) 145C3340-10 having manufacturing CAGE code 59213, a link P/N 145C3340-10 having an unknown manufacturing CAGE code, a link with an unknown P/N having manufacturing CAGE code 59213, or a link with an unknown P/N and unknown manufacturing CAGE code, installed.

(1) Columbia Helicopters, Inc., Model 234 helicopters, certificated in any category; and

(2) Restricted category Model CH-47D helicopters; current type certificate holders include, but are not limited to, Billings Flying Service, Inc., Columbia Helicopters, Inc, Tandem Rotor, LLC, and Unical Air Inc.

**Note 1 to paragraph (c):**                             A flight control rigid connecting link is also referred to as a rigid connecting link in related material.                        

**Note 2 to paragraph (c):**                             The P/N and manufacturing CAGE code information may be located on the tube of the link assembly. Information about the location of the P/N and manufacturing CAGE code is available in Boeing Service Bulletin CH-47, No. 145-67-1047, dated May 22, 2024.                        

## (d) Subject

Joint Aircraft System Component (JASC) Code: 2700, Flight control systems.

## (e) Unsafe Condition

This AD was prompted by two reports of a link failure, due to a manufacturing defect. The FAA is issuing this AD to address non-conforming links. The unsafe condition, if not addressed, could result in a link failure within the flight control system due to fatigue and subsequent immediate loss of control of the helicopter.

## (f) Compliance

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

## (g) Required Actions

Within 5 days after the effective date of this AD, remove the link from service and replace it with an airworthy link.

## (h) Parts Installation Prohibition

As of the effective date of this AD, do not install a link identified in the introductory text of paragraph (c) of this AD on any helicopter.

## (i) Special Flight Permit

Special flight permits are prohibited.

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

                            (1) The Manager, West Certification 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 West Certification Branch, send it to the attention of the person identified in paragraph (k)(1) of this AD. Information may be emailed to:                             *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.

## (k) Additional Information

                            (1) For more information about this AD, contact David Herron, Aviation Safety Engineer, FAA, 3960 Paramount Boulevard, Lakewood, CA 90712; phone: (206) 231-3544; email:                             *david.herron@faa.gov.*

                            (2) For Boeing material identified in this AD that is not incorporated by reference, contact Billings Flying Service, Inc., 309 Jellison Road, Billings, MT 59101; phone: (406) 252-6937; email:                             *jed@flybfscom.*

## (l) Material Incorporated by Reference

None.

Issued on October 3, 2024.

Steven W. Thompson,

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

[FR Doc. 2024-23547 Filed 10-8-24; 11:15 am]

BILLING CODE 4910-13-P