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###### Department of Transportation

###### Federal Aviation Administration

          - 14 CFR Part 39
          - [Docket No. FAA-2024-0232; Project Identifier MCAI-2023-00353-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 certain Bell Textron Canada Limited Model 407 helicopters. This proposed AD was prompted by a report that a certain part-numbered fuel system standpipe assembly (standpipe) may have sharp edges at the interval weld joints due to a quality escape during the manufacturing process. This proposed AD would require inspecting certain fuel system parts and, depending on the inspection results, taking corrective actions and performing a fuel quantity gauging system calibration. Depending on the results of the fuel quantity gauging system calibration, this proposed AD would require performing additional corrective action and repeating the fuel quantity gauging system calibration. The FAA is proposing this AD to address the unsafe condition on these products.

# DATES:

The FAA must receive comments on this NPRM by April 5, 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-2024-0232; 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 service information identified in this NPRM, 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 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.

# FOR FURTHER INFORMATION CONTACT:

                        Michael Hughlett, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (817) 222-5889; email:                         *michael.hughlett@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-2024-0232; Project Identifier MCAI-2023-00353-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                           ( print page 12793)                        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 Michael Hughlett, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (817) 222-5889; email:                     *michael.hughlett@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

Transport Canada, which is the aviation authority for Canada, issued Transport Canada AD CF-2023-11, dated February 23, 3023 (Transport Canada AD CF-2023-11), to correct an unsafe condition on Bell Textron Canada Limited Model 407 helicopters, serial numbers 54832 through 54931, 54933 through 54939, and 54942 through 54954. Transport Canada advises that, due to a quality escape, standpipe part number (P/N) 407-062-032-103 may have been delivered with sharp edges at the internal weld joints.

Accordingly, Transport Canada AD CF-2023-11 requires a one-time inspection of standpipe P/N 407-062-032-103 for sharp edges, and depending on the inspection results, reworking the standpipe. Transport Canada AD CF-2023-11 also requires inspecting certain parts of the fuel quantity harness assembly (harness assembly) for damage. Depending on the inspection results, Transport Canada AD CF-2023-11 requires contacting Bell for disposition results of the harness assembly and replacing any unserviceable harness assembly.

                    You may examine the Transport Canada AD in the AD docket at                     *regulations.gov*                     under Docket No. FAA-2024-0232.                

## Related Service Information Under 1 CFR Part 51

The FAA reviewed Bell Alert Service Bulletin 407-21-124, dated February 1, 2022, which specifies procedures for a one-time visual inspection of the internal joint welds of standpipe P/N 407-062-032-103. If there are any sharp edges, this service information specifies rework procedures, which include deburring the sharp edges, removing all residue, and applying a chemical film. This service information also specifies procedures to remove and inspect the harness assembly connectors for any damage to the electrical pins and inspect the insulation tubing and wires for any cracks and chafing.

Additionally, this service information specifies if any damage is found, contacting product support engineering and submitting certain information. Finally, this service information specifies instructions for various fuel procedures and checks.

The FAA also reviewed Fuel Quantity Gauging System, DMC-407-A-95-65-10-01A-273A-A, Issue 002, dated June 2, 2022, of Bell Model 407 Maintenance Manual, BHT-407-MM, Issue No. 014, dated December 12, 2023, which specifies procedures for a fuel quantity gauging system calibration procedure and inspecting the fuel quantity display information.

                    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**                    .                

## FAA's Determination

These helicopters have been approved by the aviation authority of Canada and are approved for operation in the United States. Pursuant to the FAA's bilateral agreement with Canada, Transport Canada has notified the FAA of the unsafe condition described in its AD. The FAA is proposing this AD after determining that the unsafe condition described previously is likely to exist or develop on other helicopters of the same type design.

## Proposed AD Requirements in This NPRM

This proposed AD would require, with the standpipe removed, inspecting its interior for any sharp edges on each internal weld joint. If there are any sharp edges on any weld joint, this proposed AD would require deburring the edges, ensuring not to exceed a certain depth into the tube. This proposed AD would then require removing all sanding residue and applying a chemical film to any bare metal surfaces. This proposed AD would also require, with the harness assembly removed, inspecting the harness assembly connectors for any mechanical damage and corrosion to the electrical pins, and inspecting the insulation tubing and wires of the harness assembly for any crack and chafing. Depending on these results, this proposed AD would require replacing the harness assembly.

If the harness assembly was required to be replaced as a result of the proposed AD requirements, this proposed AD would require performing a fuel quantity gauging system calibration. Depending on the calibration results, this proposed AD would require replacing the harness assembly and repeating the fuel quantity gauging system calibration.

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

Transport Canada AD CF-2023-11 requires contacting Bell for disposition instructions if damage is found on the harness assembly, whereas this proposed AD would require removing an affected harness assembly from service and replacing it with an airworthy harness assembly.

## Costs of Compliance

The FAA estimates that this AD, if adopted as proposed, would affect 51 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.

Inspecting the interior of the standpipe would take approximately 1 work-hour for an estimated cost of $85 per helicopter and $4,335 for the U.S. fleet.

Inspecting the harness assembly connectors, insulation tubing, and wiring would take approximately 1 work-hour for an estimated cost of $85 per helicopter and $4,335 for the U.S. fleet.

If required, deburring, cleaning, and applying a chemical film to each affected weld joint would take approximately 0.5 work-hour for an estimated cost of $43 per weld joint.

If required, replacing an affected harness assembly would take approximately 1 work-hour and parts would cost approximately $1,071 for an estimated cost of $1,156 per harness replacement.

If required, performing a fuel quantity gauging system calibration would take approximately 10 work-hours for an estimated cost of $850 per procedure.

The FAA has included all known costs in its cost estimate. According to the manufacturer, however, some of the costs of this proposed 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                           ( print page 12794)                        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: 

**Bell Textron Canada Limited:**                         Docket No. FAA-2024-0232; Project Identifier MCAI-2023-00353-R.                    

## (a) Comments Due Date

The FAA must receive comments on this airworthiness directive (AD) by April 5, 2024.

## (b) Affected ADs

None.

## (c) Applicability

This AD applies to Bell Textron Canada Limited Model 407 helicopters, serial numbers 54832 through 54931 inclusive, 54933 through 54939 inclusive, and 54942 through 54954 inclusive, certificated in any category, with a fuel system standpipe assembly (standpipe) part number 407-062-032-103 installed.

## (d) Subject

Joint Aircraft System Component (JASC) Code: 2897, Fuel system wiring.

## (e) Unsafe Condition

This AD was prompted by a report that certain standpipes may have sharp edges at the interval weld joints due to a quality escape during the manufacturing process. The FAA is issuing this AD to detect sharp edges in the standpipe. The unsafe condition, if not addressed, could result in fuel quantity system wiring damage, loss of erratic fuel quantity indication, or fuel tank ignition.

## (f) Compliance

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

## (g) Requirements

(1) Within 300 hours time-in-service (TIS) or 6 months after the effective date of this AD, whichever occurs first, accomplish the actions required by paragraphs (g)(1)(i) and (ii) of this AD.

(i) With the standpipe removed from the aft fuel cell, inspect the interior of the standpipe for any sharp edges on each internal weld joint, as shown in Figure 1 of Bell Alert Service Bulletin 407-21-124, dated February 1, 2022. If there is a sharp edge on any internal weld joint, before further flight, deburr the edges of each affected weld joint using an aluminum oxide abrasive cloth or paper, or equivalent, ensuring not to exceed 0.015 in (0.38 mm) depth into the tube material at a 45-degree angle to the weld joint. Then, using a clean cloth dampened with isopropyl alcohol or equivalent, remove all sanding residue from the weld joint and apply a chemical film material to any bare metal surfaces.

(ii) With the fuel quantity harness assembly (harness assembly) removed, inspect the harness assembly connectors for any mechanical damage and corrosion to the electrical pins and inspect the insulation tubing and wires for any cracks and chafing. For the purposes of this AD, mechanical damage is indicated by deterioration of the connections or pins.

(A) If there is any corrosion or mechanical damage, before further flight, remove the harness assembly from service and replace it with an airworthy harness assembly.

(B) If there is a crack or any chafing, before further flight, remove the harness assembly from service and replace it with an airworthy harness assembly.

(2) If the harness assembly was required to be replaced as a result of the inspection required by paragraph (g)(1)(ii) of this AD or by this paragraph, before further flight, with the standpipe and harness assembly installed, perform a fuel quantity gauging system calibration in accordance with paragraphs 4 through 18 of Fuel Quantity Gauging System, DMC-407-A-95-65-10-01A-273A-A, Issue 002, dated June 2, 2022, of Bell Model 407 Maintenance Manual, BHT-407-MM, Issue No. 014, dated December 12, 2023. As a result of the fuel quantity gauging system calibration, if a fuel level does not indicate the correct reading or displays no reading, before further flight, remove the harness assembly from service and replace it with an airworthy harness assembly; and repeat the actions required by this paragraph for the newly installed harness assembly.

## (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. The following provisions also apply to this AD.

## (i) Related Information

                        (1) For more information about this AD, contact Michael Hughlett, Aviation Safety Engineer, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 11590; phone: (817) 222-5889; email:                         *michael.hughlett@faa.gov.*

                        (2) Refer to Transport Canada AD CF-2023-11, dated February 23, 2023, for related information. This Transport Canada AD may be found in the AD docket at                         *regulations.gov*                         under Docket No. FAA-2024-0232.                    

## (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) Bell Alert Service Bulletin 407-21-124, dated February 1, 2022.

(ii) Fuel Quantity Gauging System, DMC-407-A-95-65-10-01A-273A-A, Issue 002, dated June 2, 2022, of Bell Model 407 Maintenance Manual, BHT-407-MM, Issue No. 014, dated December 12, 2023.

                        (3) For Bell service information identified in this AD, 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.*

                        (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                               ( print page 12795)                            information on the availability of this material at the FAA, call (817) 222-5110.                    

                        (5) You may view this material at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, visit                         *www.archives.gov/​federal-register/​cfr/​ibr-locations*                         or email                         *fr.inspection@nara.gov.*

Issued on February 12, 2024.

Victor Wicklund,

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

[FR Doc. 2024-03288 Filed 2-16-24; 8:45 am]

BILLING CODE 4910-13-P