2021-26037. 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 AS332L2 and EC225LP helicopters. This proposed AD was prompted by a report of loss of tightening torque on the nut that attaches the tail gear box (TGB) bevel wheel. This proposed AD would require repetitive inspections (measurements) of the angular clearances of the TGB, and, depending on the findings, replacement of the TGB with a serviceable TGB, as specified in a European Union Aviation Safety Agency (EASA) AD, which is proposed for incorporation by reference (IBR). This proposed AD would also provide terminating action for certain repetitive inspections. 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 January 18, 2022.

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 https://www.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.

For EASA material that is proposed for IBR in this AD, contact EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; telephone [phone]; email [e-mail]; internet www.easa.europa.eu. You may find the EASA material on the EASA website at https://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 [phone]. This material is also available at https://www.regulations.gov by searching for and locating Docket No. FAA-2021-1018.

Examining the AD Docket

You may examine the AD docket at https://www.regulations.gov by searching for and locating Docket No. FAA-2021-1018; 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.

FOR FURTHER INFORMATION CONTACT:

Andrea Jimenez, Aerospace Engineer, COS Program Management Section, Operational Safety Branch, Compliance & Airworthiness Division, 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-2021-1018; Project Identifier MCAI-2021-00902-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 https://www.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 Andrea Jimenez, Aerospace Engineer, COS Program Management Section, Operational Safety Branch, Compliance & Airworthiness Division, 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

The EASA, which is the Technical Agent for the Member States of the European Union, has issued EASA AD 2021-0184R1, dated October 8, 2021 (EASA AD 2021-0184R1), to correct an unsafe condition for Airbus Helicopters, formerly Eurocopter, Eurocopter France, Aerospatiale, Model AS 332 L2 and EC 225 LP helicopters, all serial numbers.

This proposed AD was prompted by a report of loss of tightening torque on the nut that attaches the TGB bevel wheel. Additionally, the subsequent investigation highlighted that loss of the tightening torque might lead to degradation of the splines between the tail rotor shaft and the TGB bevel wheel. The investigation is still on-going to identify the root cause of the tightening torque loss. The FAA is proposing this AD to address loss of tightening torque on the nut that attaches the TGB bevel wheel, which, if not corrected, could lead to structural failure of the TGB drive, resulting in reduced, or loss of, control of the helicopter. See EASA AD 2021-0184R1 for additional background information.

Related Service Information Under 1 CFR Part 51

EASA AD 2021-0184R1 requires repetitive inspections (measurements) of the angular clearances of the TGB, and, depending on the findings, additional repetitive inspections (measurements) of the angular clearances of the TGB at a reduced interval and replacement of the TGB with a serviceable TGB. EASA AD 2021-0184R1 provides terminating action for the repetitive inspections at the reduced interval for a helicopter if, during two consecutive inspections, the value of the measured angular clearance remains unchanged for that helicopter.

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.

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 the same type design.

Proposed AD Requirements in This NPRM

This proposed AD would require accomplishing the actions specified in EASA AD 2021-0184R1, described previously, as incorporated by reference, except for any differences identified as exceptions in the regulatory text of this proposed 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 2021-0184R1 by reference in the FAA final rule. This proposed AD would, therefore, require compliance with EASA AD 2021-0184R1 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 2021-0184R1 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 2021-0184R1. Service information referenced in EASA AD 2021-0184R1 for compliance will be available at https://www.regulations.gov by searching for and locating Docket No. FAA-2021-1018 after the FAA final rule is published.

Interim Action

The FAA considers this proposed AD would be an interim action. If final action is later identified, the FAA might consider further rulemaking then.

Costs of Compliance

The FAA estimates that this AD, if adopted as proposed, would affect 38 helicopters of U.S. Registry. The FAA estimates the following costs to comply with this proposed AD:

Estimated Costs for Required Actions

Action	Labor cost	Parts cost	Cost per product	Cost on U.S. operators
Inspection of TGB Clearance	2 work-hours × $85 per hour = $170 per inspection cycle	$0	$170 per inspection cycle	$6,460 per inspection cycle.

The FAA estimates the following costs to do any necessary on-condition action that would be required based on the results of any required actions. The FAA has no way of determining the number of helicopters that might need this on-condition action:

Estimated Costs of On-Condition Actions

Action	Labor cost	Parts cost	Cost per product
Replacement of TGB	33 work-hours × $85 per hour = $2,805	Up to $410,000	Up to $412,805.

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-2021-1018; Project Identifier MCAI-2021-00902-R.

(a) Comments Due Date

The FAA must receive comments on this airworthiness directive (AD) by January 18, 2022.

(b) Affected ADs

None.

(c) Applicability

This AD applies to all Airbus Helicopters Model AS332L2 and EC225LP helicopters, certificated in any category.

(d) Subject

Joint Aircraft Service Component (JASC) Code: 6400, Tail Rotor System.

(e) Unsafe Condition

This AD was prompted by a report of loss of tightening torque on the nut that attaches the tail gear box (TGB) bevel wheel. The FAA is issuing this AD to address loss of tightening torque on the nut that attaches the TGB bevel wheel, which, if not corrected, could lead to structural failure of the TGB drive, resulting 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 paragraph (h) of this AD: Comply with all required actions and compliance times specified in, and in accordance with, European Union Aviation Safety Agency (EASA) AD 2021-0184R1, dated October 8, 2021 (EASA AD 2021-0184R1).

(h) Exceptions to EASA AD 2021-0184R1

(1) Where EASA AD 2021-0184R1 requires compliance in terms of flight hours, this AD requires using hours time-in-service.

(2) Where EASA AD 2021-0184R1 refers to August 19, 2021 (the effective date of EASA AD 2021-0184, dated August 5, 2021), this AD requires using the effective date of this AD.

(3) Where the service information referenced in EASA AD 2021-0184R1 specifies sending parts to the manufacturer or an approved repair station to be examined, this AD does not include that requirement.

(4) This AD does not mandate compliance with the “Remarks” section of EASA AD 2021-0184R1.

(i) No Reporting Requirement

Although the service information referenced in EASA AD 2021-0184R1 specifies to submit certain information to the manufacturer, this AD does not include that requirement.

(j) Special Flight Permit

Special flight permits may be permitted provided that there are no passengers on board.

(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)(2) 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.

(l) Related Information

(1) For EASA AD 2021-0184R1, contact EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; telephone [phone]; email [e-mail]; internet www.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 [phone]. This material may be found in the AD docket at https://www.regulations.gov by searching for and locating Docket No. FAA-2021-1018.

(2) For more information about this AD, contact Andrea Jimenez, Aerospace Engineer, COS Program Management Section, Operational Safety Branch, Compliance & Airworthiness Division, FAA, 1600 Stewart Ave., Suite 410, Westbury, NY 11590; telephone [phone]; email [e-mail].

Issued on November 23, 2021.

Lance T. Gant,

Director, Compliance & Airworthiness Division, Aircraft Certification Service.