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 certain Airbus Helicopters Model AS332C, AS332C1, AS332L, and AS332L1 helicopters. This proposed AD was prompted by a report of a yaw control failure that was the result of the disconnection of the tail rotor hub (TRH) pitch control rod from the tail rotor servo-control, which resulted from a seized TRH bearing. The TRH bearing had grease dissolving after contamination by leaked hydraulic fluid from the tail rotor servo-control that came through the TRH assembly boot. This proposed AD would require repetitive inspections for hydraulic leaks, corrective actions if necessary, and an optional modification which constitutes terminating action, as specified in a European Union Aviation Safety Agency (EASA) AD, which is proposed for incorporation by reference (IBR). 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 7, 2021.

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: 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.

For material that is proposed for IBR in this AD, contact the EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; phone: +49 221 8999 000; email: ADs@easa.europa.eu; internet: www.easa.europa.eu. You may find this 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 817-222-5110. It is also available in the AD docket on the internet at https://www.regulations.gov by searching for and locating Docket No. FAA-2021-0333.

Examining the AD Docket

You may examine the AD docket on the internet at https://www.regulations.gov by searching for and locating Docket No. FAA-2021-0333; 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. Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT:

Hal Jensen, Aerospace Engineer, Operational Safety Branch, FAA, 950 L'Enfant Plaza SW, Washington, DC 20024; phone: 202-267-9167; email: hal.jensen@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-2021-0333; Project Identifier MCAI-2020-00252-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 proposal.

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 Hal Jensen, Aerospace Engineer, Operational Safety Branch, FAA, 950 L'Enfant Plaza SW, Washington, DC 20024; phone: 202-267-9167; email: hal.jensen@faa.gov. Any commentary that the FAA receives that is not specifically designated as CBI will be placed in the public docket for this rulemaking.

Discussion

The EASA, which is the Technical Agent for the Member States of the European Union, has issued EASA AD 2020-0021, dated February 6, 2020 (EASA AD 2020-0021) (also referred to as the Mandatory Continuing Airworthiness Information, or the MCAI), to correct an unsafe condition for all Airbus Helicopters Model AS332C, AS332C1, AS332L, and AS332L1 helicopters. Although EASA AD 2020-0021 applies to all Model AS332C, AS332C1, AS332L, and AS332L1 helicopters, this proposed AD applies to helicopters with an affected part installed instead.

This proposed AD was prompted by a report of a yaw control failure that was the result of the disconnection of the TRH pitch control rod from the tail rotor servo-control, which resulted from a seized TRH bearing. The TRH bearing had grease dissolving after contamination by leaked hydraulic fluid from the tail rotor servo-control that came through the TRH assembly boot. The FAA is proposing this AD to address seized TRH bearings, which could reduce the effectiveness of the pitch control of the tail rotor system, possibly resulting in reduced yaw control of the helicopter. See the MCAI for additional background information.

Related Service Information Under 1 CFR Part 51

EASA AD 2020-0021 describes procedures for repetitive inspections for hydraulic leaks, corrective actions if necessary (i.e., replacement of the pitch control rod bearing of the affected TRH assembly), and an optional modification (i.e., installation of a TRH assembly having certain part numbers) which constitutes terminating action.

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 and Requirements of This Proposed AD

These products have been approved by the aviation authority of another country, and are approved for operation in the United States. Pursuant to the bilateral agreement with the State of Design Authority, the FAA has been notified of the unsafe condition described in the MCAI referenced above. The FAA is proposing this AD after evaluating all the relevant information and determining the unsafe condition described previously is likely to exist or develop in other products of the same type design.

Proposed AD Requirements

This proposed AD would require accomplishing the actions specified in EASA AD 2020-0021, 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 initially worked with Airbus and EASA to develop a process to use certain EASA ADs as the primary source of information for compliance with requirements for corresponding FAA ADs. The FAA has since coordinated with other manufacturers and civil aviation authorities (CAAs) to use this process. As a result, EASA AD 2020-0021 will be incorporated by reference in the FAA final rule. This proposed AD would, therefore, require compliance with EASA AD 2020-0021 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 the EASA AD 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 the EASA AD. Service information specified in EASA AD 2020-0021 that is required for compliance with EASA AD 2020-0021 will be available on the internet at https://www.regulations.gov by searching for and locating Docket No. FAA-2021-0333 after the FAA final rule is published.

Costs of Compliance

The FAA estimates that this proposed AD affects 10 helicopters of U.S. registry. The FAA estimates the following costs to comply with this proposed AD:

The FAA estimates the following costs to do any necessary on-condition actions 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 these on-condition actions:

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:

Airbus Helicopters: Docket No. FAA-2021-0333; Project Identifier MCAI-2020-00252-R.

(a) Comments Due Date

The FAA must receive comments by June 7, 2021.

(b) Affected Airworthiness Directives (ADs)

None.

(c) Applicability

This AD applies to Airbus Helicopters Model AS332C, AS332C1, AS332L, and AS332L1 helicopters, certificated in any category, with a tail rotor hub (TRH) assembly, having part number (P/N) 332A33-0001-05 or P/N 332A33-0001-06, installed.

(d) Subject

Joint Aircraft System Component (JASC) Code 6420, Tail rotor head.

(e) Reason

This AD was prompted by a report of a yaw control failure that was the result of a disconnection of the TRH pitch control rod from the tail rotor servo-control, which resulted from a seized TRH bearing. The TRH bearing had grease dissolving after contamination by leaked hydraulic fluid from the tail rotor servo-control that came through the TRH assembly boot. The FAA is issuing this AD to address seized TRH bearings, which could reduce the effectiveness of the pitch control of the tail rotor system, possibly resulting in reduced yaw 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 2020-0021, dated February 6, 2020 (EASA AD 2020-0021).

(h) Exceptions to EASA AD 2020-0021

(1) Where EASA AD 2020-0021 refers to its effective date, this AD requires using the effective date of this AD.

(2) The “Remarks” section of EASA AD 2020-0021 does not apply to this AD.

(3) Where EASA AD 2020-0021 refers to flight hours (FH), this AD requires using hours time-in-service.

(4) Where paragraph (1) of EASA AD 2020-0021 requires doing inspections “in accordance with the instructions of the ASB [alert service bulletin],” this AD requires accomplishing a visual inspection for any hydraulic fluid leak at the TRH boot.

(5) Where EASA AD 2020-0021 refers to February 28, 2004 (the effective date of Direction Générale de l'Aviation Civile (DGAC) AD F-2004-031, dated February 18, 2004), this AD requires using the effective date of this AD.

(i) 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 (j)(2) 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.

(j) Related Information

(1) For EASA AD 2020-0021, contact the EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; phone: +49 221 8999 000; email: ADs@easa.europa.eu; internet: www.easa.europa.eu. You may find this EASA AD 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 817-222-5110. This material may be found in the AD docket on the internet at https://www.regulations.gov by searching for and locating Docket No. FAA-2021-0333.

(2) For more information about this AD, contact Hal Jensen, Aerospace Engineer, Operational Safety Branch, FAA, 950 L'Enfant Plaza SW, Washington, DC 20024; phone: 202-267-9167; email: hal.jensen@faa.gov.