Airworthiness Directives; Various Helicopters

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to adopt a new airworthiness directive (AD) for various helicopters modified by certain supplemental type certificates (STCs) that approve the installation of an emergency float kit or an emergency float with liferaft kit. This proposed AD was prompted by the results of an accident investigation and subsequent reports of difficulty pulling the emergency float kit float activation handle installed on the pilot cyclic. This proposed AD would require repetitively inspecting the pull force on the float activation handle and, depending on the results, accomplishing corrective actions. For certain model helicopters, this proposed AD would also require removing from service and replacing certain part-numbered float inflation reservoirs (reservoirs) and pull cable assemblies (cables) with certain other part-numbered reservoirs and cables. Finally, this proposed AD would prohibit installing certain part-numbered reservoirs and cables on certain helicopters. The FAA is proposing this AD to address the unsafe condition on these products.

DATES:

The FAA must receive comments on this proposed AD by June 10, 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-2024-1004; 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 Dart Aerospace service information identified in this NPRM, contact Dart Aerospace, LTD., 1270 Aberdeen St., Hawkesbury, ON, K6A 1K7, Canada; phone: 1-613-632-5200; Fax: 1-613-632-5246; or at dartaero.com.

• You may view this service information at the FAA, Office of the Regional Counsel, Southwest Region, 10101 Hillwood Parkway, Room 6N-321, Fort Worth, TX 76177. For information on the availability of this material at the FAA, call (817) 222-5110.

Other Related Service Information: For additional Dart Aerospace service information identified in this NPRM, use the Dart Aerospace, LTD., contact information under Material Incorporated by Reference above. You may also view this service information at the FAA contact information under Material Incorporated by Reference above.

FOR FURTHER INFORMATION CONTACT:

Johann Magana, Aviation Safety Engineer, FAA, 3960 Paramount Boulevard, Lakewood, CA 90712; phone: (562) 627-5322; email: johann.magana@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-2024-1004; Project Identifier AD-2023-01058-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 Johann Magana, Aviation Safety Engineer, FAA, 3960 Paramount Boulevard, Lakewood, CA 90712; phone: (562) 627-5322; email: johann.magana@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 reports of an accident involving an Airbus Helicopters Model AS350B2 helicopter impacting a body of water during an autorotation. The left-hand and right-hand emergency floats did not inflate symmetrically, and the helicopter subsequently capsized.

During the accident investigation, the FAA learned of reports of difficulty pulling the emergency float kit float activation handle installed on the pilot cyclic. Asymmetric inflation of the float system and difficulty deploying the float system from the float activation handle installed on the pilot cyclic can be caused by improperly installed cables. These emergency float kits utilize a system of cables to activate and release compressed gas from the float cylinders into the floats. Proper installation of the cables allows the two float cylinders installed on the aircraft to activate simultaneously, allowing for proper distribution of gas to all floats in the system. Improperly installed cables, if not addressed, could result in loss of the left or right-hand float, causing the helicopter to roll to one side but remain buoyant, or loss of both floats, causing the helicopter to capsize underwater.

Accordingly, the FAA issued AD 2020-02-23, Amendment 39-21027 (85 FR 8150, February 13, 2020) (AD 2020-02-23), for Airbus Helicopters Model AS350B, AS350BA, AS350B1, AS350B2, AS350B3, AS350C, AS350D, and AS350D1 helicopters modified by STC SR00470LA, and Airbus Helicopters Model AS355E, AS355F, AS355F1, AS355F2, AS355N, and AS355NP helicopters modified by STC SR00645LA. AD 2020-02-23 requires repetitive inspections of the installation of the cables on the emergency float kits. After AD 2020-02-23 was issued, the National Transportation Safety Board reported that similar deficiencies may remain unresolved in other similar FAA-approved emergency flotation systems.

Additionally, after AD 2020-02-23 was issued, the FAA determined additional design approval holders that use the same float activation pull system may have similar deployment mechanism deficiencies as the unsafe condition addressed in AD 2020-02-23. Consequently, this proposed AD would require repetitively inspecting the pull force on the float activation handle to detect and address improperly installed cables and, depending on the results, accomplishing corrective actions. This condition, if not addressed, could result in loss of the left-hand or right-hand float, causing the helicopter to roll to one side, or loss of both floats, causing the helicopter to capsize underwater.

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 designs.

Related Service Information Under 1 CFR Part 51

The FAA reviewed DART Aerospace Operation Instructional Manual for General Pull Cable Rigging and Testing Procedure, Revision A, dated December 23, 2020. This service information specifies procedures for testing the pull cable rigging on the DART Aerospace emergency float and liferaft systems using certain part-numbered pull cable test tools.

The FAA also reviewed DART Aerospace Service Bulletin (SB) No. SB2020-09, Revision A, dated March 16, 2021, DART Aerospace SB No. SB2021-01, Revision A, dated December 28, 2021, DART Aerospace SB No. SB2021-02, dated April 30, 2021, DART Aerospace SB No. SB2021-03, dated June 30, 2021, and DART Aerospace SB No. SB2022-01, dated March 14, 2022. This service information specifies procedures for inspecting the installation of the cable emergency float kits ( e.g., inspecting for activation pull forces on the float activation handle), readjusting the cable rigging if improperly installed, and contacting DART if readjusting the rigging is not successful. This service information also specifies optional procedures for deactivating the emergency float system as inoperative and reporting compliance to DART.

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 .

Other Related Service Information

The FAA reviewed DART Aerospace SB No. SB 2022-03, dated May 12, 2023, for Model R44 and R44 II helicopters, which specifies procedures for removing and replacing certain-part numbered reservoirs and cables with new part-numbered reservoirs and cables. This service information also specifies procedures for revising the rotorcraft flight manual and recording compliance with the service information in the aircraft logbook.

Proposed AD Requirements in This NPRM

This proposed AD would require repetitively inspecting the installation of the cables on certain emergency float systems and, depending on the results, repairing the cable installation or, deactivating and placarding the emergency float system as inoperative. For certain helicopters, this proposed AD would also require removing from service and replacing certain part-numbered reservoirs and cables with other part-numbered reservoirs and cables. Additionally, this proposed AD would prohibit installing certain part-numbered reservoirs and cables on certain helicopters.

Differences Between This Proposed AD and the Service Information

The service information specifies a one-time pull cable test, whereas this proposed AD would require repetitively inspecting the pull force on the float activation handle.

Where the service information specifies contacting DART, this proposed AD would require actions in accordance with FAA-approved procedures.

Appendix A of the service information specifies to ty-wrap the pin into place on the pilot collective and contacting DART customer service for a resolution, whereas this proposed AD would require accomplishing corrective actions in accordance with FAA-approved procedures.

Costs of Compliance

The FAA estimates that this AD, if adopted as proposed, would affect 1,150 emergency float kits or emergency float with liferaft kits installed on helicopters of U.S. registry. The FAA estimates the following costs to comply with this proposed AD. Labor costs are estimated at $85 per work-hour.

Inspecting the pull force on the float activation handle would take approximately 1 work-hour with one test kit costing approximately $2,000 for an estimated cost of $2,085 per helicopter and $2,397,750 for the U.S. fleet, per inspection cycle.

Replacing a reservoir and cable (Model R44 and R44 II helicopters) would take approximately 2 work-hours and parts would cost approximately $5,800 for an estimated cost of $5,970 per helicopter.

The FAA has no way of determining what repairs may be required following the inspection required by this proposed AD, the number of helicopters that may need repairs, or the costs to perform repairs. However, if required as a repair, replacing and adjusting an affected cable would take approximately 8 work-hours and parts would cost approximately $255 for an estimated cost of $935 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

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.

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

Various Helicopters: Docket No. FAA-2024-1004; Project Identifier AD-2023-01058-R.

(a) Comments Due Date

The FAA must receive comments on this airworthiness directive (AD) by June 10, 2024.

(b) Affected ADs

None.

(c) Applicability

This AD applies to the helicopters identified in paragraphs (c)(1) through (8) of this AD, certificated in any category.

(1) Airbus Helicopters Model AS350B, AS350BA, AS350B1, AS350B2, AS350B3, AS350C, AS350D, AS350D1, AS355E, AS355F, AS355F1, AS355F2, and AS355N helicopters modified by Supplemental Type Certificate (STC) SR00831LA; Model EC120B helicopters modified by STC SR00780LA; and Model EC130B4 helicopters modified by STC SR01687LA.

Note 1 to paragraph (c)(1): Helicopters with an AS350B3e designation are Model AS350B3 helicopters.

(2) Airbus Helicopters Deutschland GmbH (AHD) Model BO-105A, BO-105C, BO-105S, and BO-105LS A-3 helicopters modified by STC SR00856LA; Model EC135P1, EC135P2, EC135P2+, EC135P3, EC135T1, EC135T2, EC135T2+, and EC135T3 helicopters modified by STC SR01855LA; and Model MBB-BK 117 C-2 and MBB-BK 117 D-2 helicopters modified by STC SR02244LA.

Note 2 to paragraph (c)(2): Helicopters with an EC135P3H designation are Model EC135P3 helicopters; helicopters with an EC135T3H designation are Model EC135T3 helicopters; and helicopters with an MBB-BK117 C-2e designation are Model MBB-BK117 C-2 helicopters.

(3) Bell Textron Inc., Model 210, 212, 412, 412CF, and 412EP helicopters modified by STC SR01779LA; and Model 412, 412CF, and 412EP helicopters modified by STC SR01459LA.

(4) Bell Textron Canada Limited Model 206A, 206B, 206L, 206L-1, 206L-3, 206L-4, and 407 helicopters modified by STC SR01535LA.

Note 3 to paragraph (c)(4): Helicopters with a 206B3 designation are Model 206B helicopters; helicopters with a 206L-1+ designation are Model 206L-1 helicopters; and helicopters with a 206L-3+ designation are Model 206L-3 helicopters.

(5) Leonardo S.p.a. Model AB412 and AB412 EP helicopters modified by STC SR01779LA.

(6) MD Helicopters, LLC, Model 369D, 369E, 369F, 369FF, 369HE, 369HM, 369HS, and 500N helicopters modified by STC SR00932LA.

(7) Robinson Helicopter Company Model R44 and R44 II helicopters modified by STC SR02049LA; and Model R66 helicopters modified by STC SR02484LA.

(8) Sikorsky Aircraft Corporation Model S-76A, S-76B, and S-76C helicopters modified by STC SR01902LA.

(d) Subject

Joint Aircraft System Component (JASC) Code: 2560, Emergency Equipment; and 3212, Emergency Flotation Section.

(e) Unsafe Condition

This AD was prompted by the results of an accident investigation and subsequent reports of difficulty pulling the emergency float kit float activation handle installed on the pilot cyclic. The FAA is issuing this AD to detect and address improperly installed cables, which can lead to difficulty deploying the float system from the float activation handle. The unsafe condition, if not addressed, could result in loss of the left-hand or right-hand float, causing the helicopter to roll to one side, or loss of both floats causing the helicopter to capsize underwater.

(f) Compliance

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

(g) Required Actions

(1) Within 100 hours time-in-service (TIS) or 30 days after the effective date of this AD, whichever occurs first, and thereafter at intervals not to exceed six months, accomplish the actions required by paragraphs (g)(1)(i) through (vi) of this AD, as applicable to your model helicopter.

(i) For Airbus Helicopters Model EC130B4 helicopters identified in paragraph (c)(1) of this AD, accomplish the actions required by paragraphs (g)(1)(i)(A) or (B) of this AD, as applicable, and paragraph (g)(1)(i)(C) of this AD, as applicable.

(A) Inspect the pull force on the float activation handle in accordance with section 2.0 (for pull cable test tool part-number (P/N) 606.7803), paragraphs 1 through 14 of DART Aerospace Operation Instructional Manual for General Pull Cable Rigging and Testing Procedure, Revision B, dated May 12, 2023 (DART OIM-11 Rev B), except if the inflation handle makes contact with the cyclic stick in paragraph 6, before further flight, perform cable rigging in accordance with FAA-approved procedures and, once the cable is properly rigged, continue with the actions required by this paragraph, and except the measurement in paragraph 8 must be 0.85 in (2.16 cm) or greater; or

(B) Inspect the pull force on the float activation handle in accordance with section 3.0 (for pull cable test tool P/N 607.1602), paragraphs 3 through 20 of DART OIM-11 Rev B, except in paragraph 3, where it states, “it is advised to mark these locations and verify the hole centers by removing the two set screws from the test tool and sliding the tool onto the shroud and aligning the tool with the marks,” replace that text with “mark these locations and verify the hole centers by removing the two set screws from the test tool and sliding the tool onto the shroud and aligning the tool with the marks,” and except the measurement in paragraph 13 must be 0.75 in (1.91 cm) or greater.

(C) If the pull force is greater than 25 lbf (111.2N) or exceeds the limits in the existing Installation Instructions or Instructions for Continued Airworthiness for your helicopter, as applicable, before further flight, comply with paragraph (g)(2) of this AD, as applicable to your model helicopter.

(ii) For Airbus Helicopters Deutschland GmbH (AHD) Model MBB-BK 117 C-2 and MBB-BK 117 D-2 helicopters identified in paragraph (c)(2) of this AD, accomplish the actions required by paragraphs (g)(1)(ii)(A) and (B) of this AD, as applicable.

(A) Inspect the pull force on the float activation handle in accordance with section 2.0 (for pull cable test tool P/N 606.7803), paragraphs 1 through 14 of DART OIM-11 Rev B, except if the inflation handle makes contact with the cyclic stick in paragraph 6, before further flight perform cable rigging in accordance with FAA-approved procedures, and except the measurement in paragraph 8 must be 0.85 in (2.16 cm) or greater.

(B) If the pull force is greater than 25 lbf (111.2N), or exceeds the limits in the existing Installation Instructions or Instructions for Continued Airworthiness for your helicopter, as applicable, before further flight, comply with paragraph (g)(2) of this AD, as applicable to your model helicopter.

(iii) For Bell Textron Inc., Model 210, 212, 412, 412CF, and 412EP helicopters identified in paragraph (c)(3) of this AD, accomplish the actions required by paragraphs (g)(1)(iii)(A) or (B) of this AD, as applicable, and paragraph (g)(1)(iii)(C) of this AD, as applicable.

(A) Inspect the pull force on the float activation handle in accordance with section 2.0 (for pull cable test tool P/N 606.7803), paragraphs 1 through 14 of DART OIM-11 Rev B, except if the inflation handle makes contact with the cyclic stick in paragraph 6, before further flight perform cable rigging in accordance with FAA-approved procedures, and except the measurement in paragraph 8 must be 0.85 in (2.16 cm) or greater; or

(B) Inspect the pull force on the float activation handle in accordance with section 3.0 (for pull cable test tool P/N 607.1602), paragraphs 3 through 20 of DART OIM-11 Rev B, except in paragraph 3, where it states, “it is advised to mark these locations and verify the hole centers by removing the two set screws from the test tool and sliding the tool onto the shroud and aligning the tool with the marks.” replace that text with “mark these locations and verify the hole centers by removing the two set screws from the test tool and sliding the tool onto the shroud and aligning the tool with the marks,” and except the measurement in paragraph 13 must be 0.75 in (1.91 cm) or greater.

(C) If the pull force is greater than 25 lbf (111.2N), or exceeds the limits in the existing Installation Instructions or Instructions for Continued Airworthiness for your helicopter, as applicable, before further flight, comply with paragraph (g)(2) of this AD, as applicable to your model helicopter.

(iv) For Bell Textron Canada Limited Model 206A, 206B, 206L, 206L-1, 206L-3, 206L-4, and 407 helicopters identified in paragraph (c)(4) of this AD, accomplish the actions required by paragraphs (g)(1)(iv)(A) and (B) of this AD, as applicable.

(A) Inspect the pull force on the float activation handle in accordance with section 2.0 (for pull cable test tool P/N 606.7803), paragraphs 1 through 14 of DART OIM-11 Rev B, except if the inflation handle makes contact with the cyclic stick in paragraph 6, before further flight perform cable rigging in accordance with FAA-approved procedures, and except the measurement in paragraph 8 must be 0.85 in (2.16 cm) or greater.

(B) If the pull force is greater than 25 lbf (111.2N), or exceeds the limits in the existing Installation Instructions or Instructions for Continued Airworthiness for your helicopter, as applicable, before further flight, comply with paragraph (g)(2) of this AD, as applicable to your model helicopter.

(v) For Robinson Helicopter Company Model R66 helicopters identified in paragraph (c)(7) of this AD, accomplish the actions required by paragraphs (g)(1)(v)(A) and (B) of this AD, as applicable.

(A) Inspect the pull force on the float activation handle in accordance with section 2.0 (for pull cable test tool P/N 607.7803), paragraphs 1 through 14 of DART OIM-11 Rev B, except if the inflation handle makes contact with the cyclic stick in paragraph 6, before further flight perform cable rigging in accordance with FAA-approved procedures, and except the measurement in paragraph 8 must be 0.85 in (2.16 cm) or greater.

(B) If the pull force is greater than 25 lbf (111.2N), or exceeds the limits in the existing Installation Instructions or Instructions for Continued Airworthiness for your helicopter, as applicable, before further flight, comply with paragraph (g)(2) of this AD, as applicable to your model helicopter.

(vi) For the helicopters identified in paragraphs (g)(1)(vi)(A) through (E) of this AD, inspect the pull force on the float activation handle in accordance with FAA-approved procedures. The threshold for this pull force inspection must not exceed 25 lbf (111.2N). If the float activation handle fails the test, (if the pull force is greater than 25 lbf (111.2N)), or exceeds the limits in the existing Installation Instructions or Instructions for Continued Airworthiness for your helicopter, as applicable, before further flight, comply with paragraph (g)(2) of this AD, as applicable to your model helicopter.

(A) Airbus Helicopters Model AS350B, AS350BA, AS350B1, AS350B2, AS350B3, AS350C, AS350D, AS350D1, AS355E, AS355F, AS355F1, AS355F2, AS355N, and EC120B helicopters identified in paragraph (c)(1) of this AD.

(B) Airbus Helicopters Deutschland GmbH (AHD) Model BO-105A, BO-105C, BO-105S, BO-105LS A-3, EC135P1, EC135P2, EC135 P2+, EC135P3, EC135T1, EC135T2, EC135T2+, and EC135T3 helicopters identified in paragraph (c)(2) of this AD.

(C) Leonardo S.p.a. Model AB412 and AB412 EP helicopters identified in paragraph (c)(5) of this AD.

(D) MD Helicopters, LLC, Model 369D, 369E, 369F, 369FF, 369HE, 369HM, 369HS, and 500N helicopters identified in paragraph (c)(6) of this AD.

(E) Sikorsky Aircraft Corporation Model S-76A, S-76B, and S-76C helicopters identified in paragraph (c)(8) of this AD.

(2) For the helicopters identified in paragraphs (g)(1)(i) through (v) of this AD, as a result of the actions required by paragraphs (g)(1)(i) through (v) of this AD, if the pull force is greater than 25 lbf (111.2N), or exceeds the limits in the existing Installation Instructions or Instructions for Continued Airworthiness for your helicopter, as applicable, before further flight, comply with either paragraph (g)(2)(i) or (ii) of this AD.

(i) Repair the cable installation in accordance with FAA-approved procedures.

(ii) Deactivate and placard the emergency float system as inoperative in accordance with Appendix A of DART Aerospace Service Bulletin (SB) No. SB2020-09, Revision A, dated March 16, 2021, DART Aerospace SB No. SB2021-01, Revision A, dated December 28, 2021, DART Aerospace SB No. SB2021-02, dated April 30, 2021, DART Aerospace SB No. SB2021-03, dated June 30, 2021, or DART Aerospace SB No. SB2022-01, dated March 14, 2022, as applicable to your model helicopter, except where Appendix A specifies ty-wrapping the pin into place on the pilot collective, and where Appendix A specifies contacting DART customer service for a resolution, accomplish the deactivation and placarding in accordance with FAA-approved procedures. If the emergency float system is deactivated and placarded as inoperative, you are not required to accomplish the actions required by paragraph (g)(1) of this AD. This AD does not allow operation with an inoperative emergency float system unless the requirements of 14 CFR 91.205, 91.213, 135.183, and 136.11 have been met.

(3) For the helicopters identified in paragraphs (g)(1)(vi)(A) through (E) of this AD, as a result of the actions required by the introductory text of paragraph (g)(1)(vi) of this AD, if the pull force is greater than 25 lbf (111.2N), before further flight, repair the cable installation, or deactivate and placard the emergency float system as inoperative in accordance with FAA-approved procedures.

(4) For Robinson Helicopter Company Model R44 and R44 II helicopters identified in paragraph (c)(7) of this AD, within 36 months or at the next float inflation reservoir (reservoir) overhaul after the effective date of this AD, whichever occurs first, perform the requirements in paragraphs (g)(4)(i) and (ii) of this AD. Thereafter, within intervals not to exceed six months, repeat the actions required by paragraph (g)(4)(ii) of this AD.

(i) Remove cable P/N 644.7501 or P/N 644.7502 from service, as applicable, and replace with cable P/N 644.7503; and remove each reservoir P/N 644.7701 from service and replace with reservoir P/N 644.7702 or P/N 644.7703.

(ii) Inspect the pull force on the float activation handle in accordance with FAA-approved procedures. The threshold for this pull force inspection must not exceed 25 lbf (111.2N). If the pull cable installation fails the test (if the pull force is greater than 25 lbf (111.2N)), before further flight, repair the cable installation, or deactivate and placard the emergency float system as inoperative in accordance with FAA-approved procedures.

(5) As of the effective date of this AD, do not install reservoir P/N 644.7701 and cable P/N 644.7501 or reservoir P/N 644.7701 and cable P/N 644.7502 on any Robinson Helicopter Company Model R44 or R44 II helicopter.

(h) 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 (i) of this AD. Information may be emailed to: 9-ANM-LAACO-AMOC-REQUESTS@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) Additional Information

For more information about this AD, contact Johann Magana, Aviation Safety Engineer, FAA, 3960 Paramount Boulevard, Lakewood, CA 90712; phone: (562) 627-5322; email: johann.magana@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) DART Aerospace Operation Instructional Manual for General Pull Cable Rigging and Testing Procedure, Revision B, dated May 12, 2023.

(ii) DART Aerospace Service Bulletin (SB) No. SB2020-09, Revision A, dated March 16, 2021.

(iii) DART Aerospace SB No. SB2021-01, Revision A, dated December 28, 2021.

(iv) DART Aerospace SB No. SB2021-02, dated April 30, 2021.

(v) DART Aerospace SB No. SB2021-03, dated June 30, 2021.

(vi) DART Aerospace SB No. SB2022-01, dated March 14, 2022.

(3) For service information identified in this AD, contact Dart Aerospace, LTD., 1270 Aberdeen St., Hawkesbury, ON, K6A 1K7, Canada; phone: 1-613-632-5200; Fax: 1-613-632-5246; or at dartaero.com.

(4) You may view this service information at the FAA, Office of the Regional Counsel, Southwest Region, 10101 Hillwood Parkway, 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 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.