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###### Department of Transportation

###### Federal Aviation Administration

          - 14 CFR Part 39
          - [Docket No. FAA-2023-1891; Project Identifier AD-2023-00612-R]
          - RIN 2120-AA64

# AGENCY:

Federal Aviation Administration (FAA), DOT.

# ACTION:

Notice of proposed rulemaking (NPRM).

# SUMMARY:

The FAA proposes to adopt a new airworthiness directive (AD) for all Centerpointe Aerospace Inc. (Centerpointe) Model S-58BT, S-58DT, S-58ET, S-58FT, S-58HT, and S-58JT helicopters. This proposed AD was prompted by an indication of a crack on the angle gearbox mount (AGBM). This proposed AD would require repetitively performing a fluorescent penetrant inspection (FPI) and depending on the results, removing the AGBM from service. The FAA is proposing this AD to address the unsafe condition on these products.

      ( print page 68003)    

# DATES:

The FAA must receive comments on this proposed AD by November 17, 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*                         by searching for and locating Docket No. FAA-2023-1891; 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 NPRM, any comments received, and other information. The street address for Docket Operations is listed above.                    

*Material Incorporated by Reference:*
      - For Centerpointe service information identified in this NPRM, contact Centerpointe Aerospace Inc. at 279 Blackland Road, Fate, TX 75189; (972) 636-9601; email Operations@avnresources.com; https://www.californiahelicopter.com. 
      - You may view this service information at the FAA, 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.

# FOR FURTHER INFORMATION CONTACT:

                        Jacob Fitch, Aviation Safety Engineer, FAA, 10101 Hillwood Pkwy., Fort Worth, TX 76177; phone: (817) 222-4130; email:                         *jacob.fitch@faa.gov*.                    

# SUPPLEMENTARY INFORMATION:

## Comments Invited

                    The FAA invites you to send any written relevant data, views, or arguments about this proposal. Send your comments to an address listed under                     **ADDRESSES**                    . Include “Docket No. FAA-2023-1891; Project Identifier AD-2023-00612-R” at the beginning of your comments. The most helpful comments reference a specific portion of the proposal, 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 proposal 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 NPRM.                

## 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 NPRM 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 NPRM, 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 NPRM. Submissions containing CBI should be sent to Jacob Fitch, Aviation Safety Engineer, FAA, 10101 Hillwood Pkwy., Fort Worth, TX 76177; phone: (817) 222-4130; email:                     *jacob.fitch@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 proposes to adopt a new AD for all Centerpointe Model S-58BT, S-58DT, S-58ET, S-58FT, S-58HT, and S-58JT helicopters. During a preflight inspection, fatigue cracking was found on a Model S-58BT helicopter in the angle supports and cross-members forming the edges of the AGBM. Due to their similarity to the Model S-58BT helicopter, the FAA has determined that Centerpointe Model S-58DT, S-58ET, S-58FT, S-58HT, and S-58JT helicopters are also affected by the same unsafe condition. This condition, if not addressed, could result in loss of the angle gearbox, resulting in loss of main rotor drive and subsequent loss of control of the helicopter.

## FAA's Determination

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

## Related Service Information Under 1 CFR Part 51

                    The FAA reviewed Centerpointe Aerospace Service Bulletin No. 58B75, dated April 26, 2023. This service information specifies procedures for repetitively performing an FPI and reporting the results to the manufacturer. 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                     **ADDRESSES**                    .                

## Proposed AD Requirements in This NPRM

This proposed AD would require repetitive FPIs of the AGBM for a crack, as specified in the service information already described, except as discussed under “Differences Between this Proposed AD and the Service Information.” This proposed AD would also require removing any cracked AGBM from service before further flight.

## Differences Between This Proposed AD and the Service Information

Where the service information specifies that the initial FPI be performed within 120 days after receipt of the service information, this proposed AD would require the initial FPI to be performed within 250 hours time-in-service. The service information specifies reporting the results of the FPI to the manufacturer, whereas this proposed AD would not.

## Costs of Compliance

The FAA estimates that this AD, if adopted as proposed, would affect 14 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 proposed AD.

Performing an FPI of the AGBM would take about 5 work-hours and parts cost $150 for an estimated cost of $575 per helicopter, and $8,050 for the U.S. fleet, per inspection.

If necessary, replacing an AGBM would take about 41 work-hours and the parts cost would be $30,000 for an estimated cost of $33,485 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                           ( print page 68004)                        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

The FAA determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would 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 this proposed regulation:

(1) Is not a “significant regulatory action” under Executive Order 12866,

(2) Would not affect intrastate aviation in Alaska, and

(3) Would 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 Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 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: 

**Centerpointe Aerospace Inc.:**                         Docket No. FAA-2023-1891; Project Identifier AD-2023-00612-R.                    

## (a) Comments Due Date

The FAA must receive comments on this airworthiness directive (AD) by November 17, 2023.

## (b) Affected ADs

None.

## (c) Applicability

This AD applies to Centerpointe Aerospace Inc, Model S-58BT, S-58DT, S-58ET, S-58FT, S-58HT, and S-58JT helicopters, certificated in any category.

## (d) Subject

Joint Aircraft System Component (JASC) Code 6300, Main Rotor Drive System.

## (e) Unsafe Condition

This AD was prompted by the discovery of a fatigue crack on the angle gearbox mount (AGBM). The FAA is issuing this AD to detect fatigue cracking of the AGBM. The unsafe condition, if not addressed, could lead to loss of the angle gearbox, resulting in loss of main rotor drive and subsequent loss of control of the helicopter.

## (f) Compliance

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

## (g) Required Actions

(1) Within 250 hours time-in-service (TIS) after the effective date of this AD, and thereafter at intervals not to exceed 250 hours TIS, perform a fluorescent penetrant inspection (FPI) to inspect for any crack on the AGBM in the eight areas depicted in the Accomplishment Instructions, Figures 1A and 1B, of Centerpointe Aerospace Service Bulletin No. 58B75, dated April 26, 2023. This FPI must be accomplished by a Level II or Level III inspector certified in the FAA-acceptable standards for nondestructive inspection personnel.

(2) If there is any crack, before further flight, remove the AGBM from service.

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

(1) The Manager, Central 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 certification office, send it to the attention of the person identified in paragraph (i) of this AD.

(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) Additional Information

                        Jacob Fitch, Aviation Safety Engineer, FAA, 10101 Hillwood Pkwy., Fort Worth, TX 76177; phone: (817) 222-4130; email:                         *jacob.fitch@faa.gov*.                    

## (j) 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 the AD specifies otherwise.

(i) Centerpointe Aerospace Service Bulletin No. 58B75, dated April 26, 2023.

(ii) [Reserved]

                        (3) For Centerpointe service information identified in this NPRM, contact Centerpointe Aerospace Inc. at 279 Blackland Road, Fate, TX 75189; (972) 636-9601; email                         *Operations@avnresources.com; https://www.californiahelicopter.com.*

(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 September 22, 2023.

Victor Wicklund,

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

[FR Doc. 2023-21684 Filed 10-2-23; 8:45 am]

BILLING CODE 4910-13-P