2024-07878. Airworthiness Directives; Airbus 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 all Airbus Helicopters Model AS350B, AS350BA, AS350B1, AS350B2, AS350D, AS355E, AS355F, AS355F1, AS355F2, and AS355N helicopters. This proposed AD was prompted by reports of debonding on the leading edge protection of certain part-numbered main rotor blades (MRBs). This proposed AD would require repetitively tap inspecting the MRB and, depending on the results, taking corrective action. This proposed AD would also prohibit installing an affected MRB on any helicopter unless its 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 proposed AD by May 31, 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: [phone].

• 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-2024-1002; 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, contact EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; telephone [phone]; email [e-mail]. You may find the EASA material on the EASA website easa.europa.eu.

• You may view this material 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 [phone]. The EASA material is also available at regulations.gov under Docket No. FAA-2024-1002.

Other Related Service Information: For Airbus Helicopters service information identified in this NPRM, contact Airbus Helicopters, 2701 North Forum Drive, Grand Prairie, TX 75052; phone [phone] or [phone]; fax [phone]; or at airbus.com/en/products-services/helicopters/hcare-services/airbusworld. You may also view this service information at the FAA contact information under Material Incorporated by Reference above.

FOR FURTHER INFORMATION CONTACT:

Dan McCully, Aviation Safety Engineer, FAA, 1600 Stewart Ave., Suite 410, Westbury, NY 11590; telephone [phone]; email [e-mail].

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-2024-1002; Project Identifier MCAI-2022-01574-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; telephone [phone]; email [e-mail]. Any commentary that the FAA receives that 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 2022-0246, dated December 12, 2022 (EASA AD 2022-0246), to correct an unsafe condition for all Airbus Helicopters Model AS 350 B, AS 350 BA, AS 350 B1, AS 350 B2, AS 350 BB, AS 350 D, AS 355 E, AS 355 F, AS 355 F1, AS 355 F2, and AS 355 N helicopters.

This proposed AD was prompted by reports of debonding on the stainless steel leading edge protection of certain part-numbered MRBs. The FAA is proposing this AD to address the debonding of the MRB leading edge protection. The unsafe condition, if not detected and corrected, could lead to significant unbalance of the main rotor, a high level of vibration, failure of the main rotor, failure of the main gearbox, and subsequent loss of control of the helicopter.

Related Service Information Under 1 CFR Part 51

EASA AD 2022-0246 requires repetitively tap inspecting affected MRBs and, depending on findings, either repairing or replacing the MRB. For certain helicopters, EASA AD 2022-0246 prohibits installing an affected MRB unless it is a serviceable part as defined within and is inspected following installation. For other certain helicopters, EASA AD 2022-0246 prohibits installing an affected MRB.

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 Service Information

The FAA also reviewed Airbus Helicopters Alert Service Bulletin No. AS350-05.01.07 and No. AS355-05.00.91, both Revision 0 and dated December 6, 2022. This service information specifies procedures for tap inspecting the stainless steel leading edge protection of the MRB and, depending on the results, repairing or sending the MRB for repair to Airbus Helicopters. The service information also specifies sending certain information to Airbus Helicopters.

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 2022-0246, described previously, as incorporated by reference, except for any differences identified as exceptions in the regulatory text of this proposed AD and except as discussed under “Differences Between this Proposed AD and the EASA AD.”

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 2022-0246 by reference in the FAA final rule. This proposed AD would, therefore, require compliance with EASA AD 2022-0246 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 2022-0246 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 2022-0246. Service information referenced in EASA AD 2022-0246 for compliance will be available at regulations.gov under Docket No. FAA-2024-1002 after the FAA final rule is published.

Differences Between This Proposed AD and the EASA AD

EASA AD 2022-0246 applies to Model AS350BB helicopters, whereas this proposed AD would not because that model is not FAA-type certificated.

Costs of Compliance

The FAA estimates that this AD, if adopted as proposed, would affect 405 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.

Tap inspecting affected MRBs for disbonding would take up to approximately 1 work-hour (up to three MRBs per helicopter) for an estimated cost of up to $85 per helicopter and $34,425 for the U.S. fleet, per inspection cycle. Replacing a blade would take approximately 6 work-hours and parts would cost up to approximately $84,000 for an estimated cost of up to $84,510 per MRB. The FAA has no data to determine the cost of or the number of helicopters that might need the MRB repaired.

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.

§ 39.13

[Amended]

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

Airbus Helicopters: Docket No. FAA-2024-1002; Project Identifier MCAI-2022-01574-R.

(a) Comments Due Date

The FAA must receive comments on this airworthiness directive (AD) by May 31, 2024.

(b) Affected ADs

None.

(c) Applicability

This AD applies to Airbus Helicopters Model AS350B, AS350BA, AS350B1, AS350B2, AS350D, AS355E, AS355F, AS355F1, AS355F2, and AS355N helicopters, certificated in any category.

(d) Subject

Joint Aircraft Service Component (JASC) Code: 6210, Main Rotor Blades.

(e) Unsafe Condition

This AD was prompted by reports of debonding on the stainless steel leading edge protection of certain main rotor blades (MRBs). The FAA is issuing this AD to address the debonding of the MRB leading edge protection. The unsafe condition, if not addressed, could result in a significant unbalance of the main rotor, a high level of vibration, failure of the main rotor, failure of the main gearbox, and subsequent 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 (EASA) AD 2022-0246, dated December 12, 2022 (EASA AD 2022-0246).

(h) Exceptions to EASA AD 2022-0246

(1) Where EASA AD 2022-0246 requires compliance in terms of flight hours, this AD requires using hours time-in-service.

(2) Where EASA AD 2022-0246 refers to its effective date, this AD requires using the effective date of this AD.

(3) Where the service information referenced in paragraphs (2) and (3) of EASA AD 2022-0246 specifies sending removed blade(s) to Airbus Helicopters, this AD does not require that action.

(4) This AD does not adopt the “Remarks” section of EASA AD 2022-0246.

(i) No Reporting Requirement

Although the service information referenced in EASA AD 2022-0246 specifies to submit certain information to the manufacturer, this AD does not include that requirement.

(j) 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 (k) of this AD. Information may be emailed to: [e-mail].

(2) Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the local flight standards district office/certificate holding district office.

(k) Related Information

For more information about this AD, contact Dan McCully, Aviation Safety Engineer, FAA, 1600 Stewart Ave., Suite 410, Westbury, NY 11590; telephone [phone]; email [e-mail].

(l) 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 this AD specifies otherwise.

(i) European Union Aviation Safety Agency (EASA) AD 2022-0246, dated December 12, 2022.

(ii) [Reserved]

(3) For EASA AD 2022-0246, contact EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; telephone [phone]; email [e-mail]; internet easa.europa.eu. You may find the EASA material on the EASA website ad.easa.europa.eu.

(4) You may view this material 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 [phone].

(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 [e-mail].

Issued on April 9, 2024.

James D. Foltz,

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