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 Department of Transportation Federal Aviation Administration 14 CFR Part 39
[Docket No. FAA-2024-2419; Project Identifier MCAI-2023-00366-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 Airbus Helicopters (Airbus) Model AS350B, AS350B1, AS350B2, AS350B3, AS350BA, AS350D, AS355E, AS355F, AS355F1, AS355F2, AS355N, AS355NP, EC130B4, and EC130T2 helicopters. This proposed AD was prompted by a manufacturer assessment that determined additional actions are necessary to improve particle detection for main gearboxes (MGBs) with certain planet gear bearings installed. This proposed AD would require repetitively inspecting the MGB bevel wheel for the presence of particles, repetitively inspecting the MGB magnetic plug for particles, and prohibit installing an affected MGB unless certain requirements are met. These actions are specified in a European Union Aviation Safety Agency (EASA) AD, which is proposed for incorporation by reference. The FAA is proposing this AD to address the unsafe condition on these products.
 DATES: The FAA must receive comments on this NPRM by December 20, 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.
                        ( print page 87822)
                    *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-2024-2419; 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, the EASA AD, any comments received, and other information. The street address for Docket Operations is listed above. *Material Incorporated by Reference:* For EASA material identified in this proposed AD, contact EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; phone: +49 221 8999 000; email:*ADs@easa.europa.eu;*
                         website: 
                        *easa.europa.eu.*
                         You may find the EASA material on the EASA website at 
                        *ad.easa.europa.eu.*
                    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. The EASA material is also available at*regulations.gov*
                         under Docket No. FAA-2024-2419. *Other Related Material:*
                         For Airbus material identified in this proposed AD, contact Airbus Helicopters, 2701 North Forum Drive, Grand Prairie, TX 75052; phone: (972) 641-0000 or (800) 232-0323; fax: (972) 641-3775; or at 
                        *airbus.com/en/products-services/helicopters/hcare-services/airbusworld.*
 FOR FURTHER INFORMATION CONTACT: Dan McCully, Aviation Safety Engineer, FAA, 1600 Stewart Ave., 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 relevant data, views, or arguments about this proposal. Send your comments to an address listed under 
                    **ADDRESSES**
                    . Include “Docket No. FAA-2024-2419; Project Identifier MCAI-2023-00366-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 Dan McCully, Aviation Safety Engineer, FAA, 1600 Stewart Ave., 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 EASA, which is the Technical Agent for the Member States of the European Union, has issued EASA AD 2023-0044, dated February 28, 2023, (EASA AD 2023-0044) to correct an unsafe condition on Airbus Model AS 350 B, AS 350 D, AS 350 B1, AS 350 B2, AS 350 BA, AS 350 BB, AS 350 B3, EC 130 B4, EC 130 T2, AS 355 E, AS 355 F, AS 355 F1, AS 355 F2, AS355 N, and AS355 NP helicopters. EASA advises that after a fleet design review for detection of particles in the MGB, it was determined that additional maintenance actions are necessary to improve detection of particles in the MGB. The FAA is proposing this AD to detect and correct the presence of particles in the MGB, which if not addressed, could result in reduced or loss of control of the helicopter. You may examine EASA AD 2023-0044 in the AD docket at 
                    *regulations.gov*
                     under Docket No. FAA-2024-2419. Material Incorporated by Reference Under 1 CFR Part 51 EASA AD 2023-0044 requires repetitive borescope visual inspections of the bevel wheel of the affected MGB for particles, collecting and analyzing any found particles, and depending on the results, further actions, accomplishing corrective action in accordance with the ASB defined within, or contacting AH [Airbus Helicopters] for further corrective action. EASA AD 2023-0044 also requires accomplishing a borescope visual inspection of the bevel wheel of the affected MGB for particles following the detection of any particles at the MGB magnetic plug during accomplishment of certain maintenance tasks and depending on the results, taking corrective action. Lastly, EASA AD 2023-0044 prohibits installing an affected MGB on any helicopter unless it is a serviceable part as defined within and certain requirements are met. 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 the 
                    **ADDRESSES**
                     section. Other Related Material The FAA reviewed Airbus Alert Service Bulletin No. AS350-05.01.04, No. AS355-05.00.87, and No. EC130-05A040, each Revision 0, and each dated January 25, 2023. This material specifies procedures for borescope inspecting the MGB bevel wheel for particles and, depending on the results, replacing a damaged epicyclic module or bevel reduction module with an airworthy part, and collecting the particles using a vacuum pump and analyzing the particles. FAA's Determination These helicopters have been approved by EASA and are approved for operation in the United States. Pursuant to the FAA's bilateral agreement with the European Union, EASA has notified the FAA about the unsafe condition described in its AD. The FAA is proposing this AD after evaluating all known relevant information and determining that the unsafe condition described previously is likely to exist or develop on other helicopters of these same type designs. Proposed AD Requirements in This NPRM This proposed AD would require accomplishing the actions specified in EASA AD 2023-0044, described previously, as incorporated by reference, except for any differences identified as exceptions in the 
                    ( print page 87823)
                    regulatory text of this proposed AD and except as discussed under “Differences Between this Proposed AD and EASA AD 2023-0044.” This proposed AD would require certain actions within compliance times specified in certain material referenced for compliance in EASA AD 2023-0044, particularly for corrective actions for scales, flakes, or splinters. Depending on the measurements of the scales, flakes, or splinters, corrective actions include close monitoring, metallurgical analysis within 50 hours time-in-serivce, or removing each affected module and additional actions when certain criteria are exceeded. 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 requirements for corresponding FAA ADs. The FAA has been coordinating this process with manufacturers and CAAs. As a result, the FAA proposes to incorporate EASA AD 2023-0044 by reference in the FAA final rule. This proposed AD would, therefore, require compliance with EASA AD 2023-0044 in its entirety through that incorporation, except for any differences identified as exceptions in the regulatory text of this proposed AD. Using common terms that are the same as the heading of a particular section in EASA AD 2023-0044 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 “Required Action(s) and Compliance Time(s)” in EASA AD 2023-0044. Material referenced in EASA AD 2023-0044 for compliance will be available at 
                    *www.regulations.gov*
                     by searching for and locating Docket No. FAA-2024-2419 after the FAA final rule is published. Differences Between This Proposed AD and EASA AD 2023-0044 EASA AD 2023-0044 applies to Model AS350BB helicopters, whereas this proposed AD would not because that model is not FAA-type certificated. Where Note 1 in the material referenced in EASA AD 2023-0044 specifies the option of 1 mechanical technician and 1 crew member, for this proposed AD, the pilot is only permitted to turn the tail rotor (b) because the other actions specified in the note must be accomplished by persons authorized under 14 CFR 43.3. Therefore, for the purposes of this proposed AD, the owner/operator (pilot) may turn the tail rotor (b) and must enter compliance with the applicable paragraph of this proposed AD in the helicopter maintenance records in accordance with 14 CFR 43.9(a) and 91.417(a)(2)(v). The pilot may perform this action because it only involves turning the tail rotor (b). This action can be performed equally well by a pilot or a mechanic. This action is an exception to the FAA's standard maintenance regulations. This proposed AD would not require complying with paragraph (2) of EASA AD 2023-0044. Instead, this proposed AD would require repetitively inspecting the MGB magnetic plug for particles and, if there is any particle, accomplishing a borescope visual inspection, as specified in paragraphs (h)(6)(i) and (ii) of this proposed AD. Where the material referenced in EASA AD 2023-0044 specifies contacting Airbus Helicopters for a certain action, this proposed AD would require accomplishing action in accordance with a method approved the FAA, EASA, or Airbus Helicopters' EASA Design Organization Approval. Costs of Compliance The FAA estimates that this AD, if adopted as proposed, would affect 522 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. A repetitive visual borescope inspection of the MGB bevel wheel would take 1 work-hour for an estimated cost of $85 per helicopter and $44,370 for the U.S. fleet, per inspection cycle. If necessary, collecting and performing a metallurgical analysis of the detected particles would take 6 work-hours for an estimated cost of $510 per helicopter, per analysis. Repetitively inspecting the magnetic plugs of the MGB would take 1 work-hour for an estimated cost of $85 per helicopter and $44,370 for the U.S. fleet, per inspection cycle. If required, close monitoring would take 2 work-hours for an estimated cost of $170 per helicopter, per close monitoring cycle. Accomplishing a visual borescope inspection of the MGB bevel wheel as a result of an MGB magnetic plug inspection would take 1 work-hour for an estimated cost of $85 per helicopter. If necessary, replacing an epicyclic module would take 56 work-hours and parts would cost $50,524 (overhauled) for an estimated cost of $55,284 per module. If necessary, replacing a bevel reduction module would take 56 work-hours and parts would cost $18,500 (overhaled) for an estimated cost of $23,260 per module. Certain corrective action could vary significantly from helicopter to helicopter. The FAA has no data to determine the costs to accomplish the corrective action. 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, 
                    ( print page 87824)
                    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: **Airbus Helicopters:**
                         Docket No. FAA-2024-2419; Project Identifier MCAI-2023-00366-R. (a) Comments Due Date The FAA must receive comments on this airworthiness directive (AD) by December 20, 2024. (b) Affected ADs None. (c) Applicability This AD applies to all Airbus Helicopters Model AS350B, AS350B1, AS350B2, AS350B3, AS350BA, AS350D, AS355E, AS355F, AS355F1, AS355F2, AS355N, AS355NP, EC130B4, and EC130T2 helicopters, certificated in any category. (d) Subject Joint Aircraft System Component (JASC) Code: 6320, Main Rotor Gearbox. (e) Unsafe Condition This AD was prompted by an assessment performed by the manufacturer which determined that additional actions are necessary to improve particle detection for main gearboxes (MGBs) with certain part-numbered planet gear bearings installed. The FAA is issuing this AD to detect and correct particles in the MGB. The unsafe condition, if not addressed, could result in reduced or loss of control of the helicopter. (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, European Union Aviation Safety Agency AD 2023-0044, dated February 28, 2023 (EASA AD 2023-0044). (h) Exceptions to EASA AD 2023-0044 (1) Where EASA AD 2023-0044 defines “serviceable MGB” as “An affected MGB which has accumulated less than 330 flight hours (FH) since new (first installation on a helicopter), or since an overhaul, or since an inspection in accordance with the instructions of the ASB;” for this AD, replace that text with “An affected MGB which has accumulated less than 330 total hours time-in-service since new (zero total hours time-in-service), since last overhaul if an overhaul has been accomplished, or since last inspection and any specified corrective action in accordance with the instructions of the ASB if an inspection and any specified corrective action by following the instructions of the ASB have been accomplished.” (2) Where EASA AD 2023-0044 requires compliance in terms of flight hours, this AD requires using hours time-in-service (TIS). (3) Where EASA AD 2023-0044 refers to its effective date, this AD requires using the effective date of this AD. (4) Where Note 1 in the material referenced in paragraph (1) of EASA AD 2023-0044 specifies the option of 1 mechanical technician and 1 crew member, for this AD, the pilot is only permitted to turn the tail rotor (b). The owner/operator (pilot) holding at least a private pilot certificate may turn the tail rotor (b) and must enter compliance with paragraph (g) of this AD in the helicopter maintenance records in accordance with 14 CFR 43.9(a) and 91.417(a)(2)(v). The record must be maintained as required by 14 CFR 91.417, 121.380, or 135.43. All other actions specified in Note 1 in the material referenced in paragraph (1) of EASA AD 2023-0044 must be accomplished by persons authorized under 14 CFR 43.3. (5) Where Note 2 in the material referenced in paragraph (1) of EASA AD 2023-0044 specifies contacting Airbus Helicopters for further instructions if the bottom of the radius (a6) of the bevel wheel (a3) or head screws (a4) (see Figure 2) are not clearly visible, this AD requires, before further flight, accomplishing action in accordance with a method approved by the FAA, EASA, or Airbus Helicopters' EASA Design Organization Approval (DOA). If approved by the DOA, the approval must include the DOA-authorized signature. (6) Instead of complying with paragraph (2) of EASA AD 2023-0044, comply with the actions required by paragraphs (h)(6)(i) and (ii) of this AD. (i) After the effective date of this AD, and within the compliance time intervals specified table 1 to paragraph (h)(6)(i) of this AD, visually inspect the MGB magnetic plug for particles. **Note 1 to paragraph (h)(6)(i):**
                         Aircraft Maintenance Manual (AMM) task 60-00-00, 6-2A, or AMM task 60-00-00, 6-2, or work card 60-00-00-602, as applicable, provides information regarding inspecting the MGB magnetic plug. Table 1 to Paragraph (
                            h
                            )(6)(
                            i
                            )—MGB Magnetic Plug Inspections
Helicopter model(s)
Initial compliance times (after the effective date of this AD)
                                 (hours TIS)
Interval compliance times (thereafter)
                                 (hours TIS)AS350B, AS350B1, AS350BA, and AS350D
5
30AS355E, AS355F, AS355F1, AS355F2, AS355N, and AS355NP
5
30AS350B2 and AS350B3
10
100EC130B4
5
150EC130T2
5
150
 (ii) If there is any particle as a result of any MGB magnetic plug inspection required by paragraph (h)(6)(i) of this AD, before further flight, borescope inspect the bevel wheel of the affected MGB for particles as required by paragraph (1) of EASA AD 2023-0044. If there is any particle as a result of the borescope inspection of the bevel wheel, before further flight, collect and analyze the particles as required by paragraph (3) of EASA AD 2023-0044. (7) Where paragraph (3) of EASA AD 2023-0044 specifies “If, during any inspection as required by paragraph (1) or (2) of this AD;” for this AD, replace that text with “If, during any inspection as required by paragraph (1) of this AD.” (8) Where the material referenced in paragraph (3) of EASA AD 2023-0044 specifies performing a metallurgical analysis and contacting Airbus Helicopters if collected particles cannot be characterized with Work Card 20-08-01-601, this AD does not require contacting Airbus Helicopter but does require performing the metallurgical analysis. (9) This AD does not allow the ferry flight provision specified in the material referenced in paragraph (3) of EASA AD 2023-0044; for this AD, refer to paragraph (j) of this AD. (10) Where the material referenced in paragraph (3) of EASA AD 2023-0044 specifies contacting Airbus Helicopters if the damaged module cannot be identified, this AD requires, before further flight, accomplishing action in accordance with a method approved by the FAA, EASA, or Airbus Helicopters' EASA DOA. If approved by the DOA, the approval must include the DOA-authorized signature. (11) Where paragraph (5) of EASA AD 2023-0044 states “to contact AH for corrective action(s) instructions, and within the compliance time specified therein, to accomplish those instructions accordingly” for this AD, replace that text with 
                        ( print page 87825)
                        “accomplishing corrective actions in accordance with a method approved by the FAA, EASA, or Airbus Helicopters' EASA DOA. If approved by the DOA, the approval must include the DOA-authorized signature.” (12) Where paragraph (7) of EASA AD 2023-0044 states “since new (first installation a helicopter), or since an overhaul, or since an inspection in accordance with the instructions of the ASB, as applicable, and, thereafter, as required by this AD;” for this AD, replace that text with “since new (zero total hours time-in-service), or since last overhaul if an overhaul has been accomplished, or since last inspection and any specified corrective action in accordance with the instructions of the ASB if an inspection and any specified corrective action by following the instructions of the ASB have been accomplished, and thereafter as required by this AD.”.” (13) This AD does not adopt the “Remarks” section of EASA AD 2023-0044. (i) No Reporting Requirement Although the material referenced in EASA AD 2023-0044 specifies to submit certain information to the manufacturer, this AD does not require that action. (j) Special Flight Permit A special flight permit may be issued in accordance with 14 CFR 21.197 and 21.199 to permit a one-time, non-revenue flight to a location where the actions required by this AD can be accomplished. This flight must be performed with only essential flight crew. (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 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 (l) 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. (l) Related Information For more information about this AD, contact Dan McCully, Aviation Safety Engineer, FAA, 1600 Stewart Ave., 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 material listed in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51. (2) You must use this material as applicable to do the actions required by this AD, unless the AD specifies otherwise. (i) European Union Aviation Safety Agency (EASA) AD 2023-0044, dated February 28, 2023. (ii) [Reserved] (3) For EASA material identified in this AD, contact EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; phone: +49 221 8999 000; email: 
                        *ADs@easa.europa.eu;*
                         website: 
                        *easa.europa.eu.*
                         You may find the EASA material on the EASA website at 
                        *ad.easa.europa.eu.* (4) 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. (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 October 29, 2024. Victor Wicklund, Deputy Director, Compliance & Airworthiness Division,  Aircraft Certification Service.


[FR Doc. 2024-25615 Filed 11-4-24; 8:45 am] BILLING CODE 4910-13-P