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 AS-365N2, AS 365 N3, EC 155B, EC155B1, and SA-365N1 helicopters. This proposed AD was prompted by a large amount of critical scale particles found on the tail rotor gearbox (TGB) chip detector magnetic plug during an unscheduled check of the TGB. The particles belonged to the double bearing (pitch control rod bearing) installed inside the TGB. This proposed AD would require repetitive inspections of the TGB chip detector for particles, analyzing any particles collected, performing a double bearing washing, repetitive replacements of certain part-numbered double bearings, and corrective actions if necessary, 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 May 26, 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: (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 EASA material that is proposed for IBR in this AD, contact EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; telephone +49 221 8999 000; email ADs@easa.europa.eu; 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 (817) 222-5110. The EASA material is also available at https://www.regulations.gov by searching for and locating Docket No. FAA-2022-0295.

Examining the AD Docket

You may examine the AD docket at https://www.regulations.gov by searching for and locating Docket No. FAA-2022-0295; 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 (516) 228-7330; email andrea.jimenez@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-2022-0295; Project Identifier MCAI-2021-00840-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 (516) 228-7330; email andrea.jimenez@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.

Background

EASA, which is the Technical Agent for the Member States of the European Union, has issued EASA AD 2021-0170, dated July 19, 2021 (EASA AD 2021-0170), to correct an unsafe condition for all Airbus Helicopters (AH), formerly Eurocopter, Eurocopter France, Aerospatiale, Sud Aviation, Model AS 365 N2, AS 365 N3, EC 155 B, EC 155 B1 and SA 365 N1 helicopters.

This proposed AD was prompted by a large amount of critical scale particles found on the TGB chip detector magnetic plug during an unscheduled check of a Model AS 365 N2 helicopter. EASA advises the particles belonged to the double bearing (pitch control rod bearing) installed inside the TGB and further advises the reported event showed a speed of degradation faster than expected. The FAA is proposing this AD to prevent bearing degradation and subsequent failure, which could result in loss of yaw control. See EASA AD 2021-0170 for additional background information.

Related Service Information Under 1 CFR Part 51

EASA AD 2021-0170 requires analyzing any particles collected during close monitoring or during any required inspections, repetitive inspections of the TGB chip detector for particles, performing a double bearing washing, and corrective actions. Corrective actions include removing an affected TGB and repairing or replacing that TGB, sending affected parts and certain information to the manufacturer, replacing a TGB chip detector or TGB electrical magnetic plug, and replacing an affected O-ring and double bearing. EASA AD 2021-0170 also requires performing a double bearing washing or performing a metallurgical analysis based on inspection results.

EASA AD 2021-0170 also requires for any double bearing part number (P/N) 704A33-651-245 or 704A33-651-246, installed on any TGB P/N 365A33-6005-09, before exceeding 610 flight hours (FH) since first installation, or within 110 FH after October 28, 2019 (the effective date of EASA AD 2019-0267-E, dated October 25, 2019), whichever occurs later, and thereafter at intervals not to exceed 500 FH, replacing the affected double bearing with a serviceable one. EASA AD 2021-0170 allows double bearing part number P/N 704A33-651-245 or 704A33-651-246 to be installed, provided it has never been installed on a helicopter and it is inspected as required by EASA AD 2021-0170. Finally, EASA AD 2021-0170 allows TGB P/N 365A33-6005-09 to be installed, provided it has a serviceable double bearing installed that is inspected as required by the EASA AD.

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 reviewed Airbus Helicopters Emergency Alert Service Bulletin (EASB) No. 01.00.24 for non FAA-type certificated military Model AS565MA, MB, MBe, SA, SB, and UB helicopters; EASB No. 01.00.71 for Model AS365N1, N2, and N3 helicopters, and non FAA-type certificated military Model AS365F, Fi, K, and K2 helicopters; EASB No. 01.31 for non FAA-type certificated military Model SA366GA helicopters; and EASB No. 04A016 for Model EC155B and B1 helicopters, each Revision 3 and dated June 14, 2021 (co-published as one document).

This service information specifies procedures to inspect the TGB chip detector for particles, analyze and define the particles by performing a metallurgical analysis, perform a washing of the double bearing, replace the double bearing, and send certain information and affected parts to the manufacturer.

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 2021-0170, 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 EASA AD 2021-0170.”

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 2021-0170 by reference in the FAA final rule. This proposed AD would, therefore, require compliance with EASA AD 2021-0170 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 2021-0170 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 2021-0170. Service information referenced in EASA AD 2021-0170 for compliance will be available at https://www.regulations.gov by searching for and locating Docket No. FAA-2022-0295 after the FAA final rule is published.

Differences Between This Proposed AD and EASA AD 2021-0170

Service information referenced in EASA AD 2021-0170 specifies sending compliance forms, and certain parts to the manufacturer; this proposed AD would not. Service information referenced in EASA AD 2021-0170 specifies contacting Airbus Helicopters for approved repairs or corrective actions if certain discrepancies are found, whereas this proposed AD would require accomplishing repairs or corrective actions using a method approved by the Manager, General Aviation and Rotorcraft Section, International Validation Branch, FAA; or EASA; or Airbus Helicopters' EASA Design Organization Approval (DOA). If approved by the DOA, the approval must include the DOA-authorized signature.

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.

Costs of Compliance

The FAA estimates that this AD, if adopted as proposed, would affect 53 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.

Analyzing any particles collected during close monitoring would take about 1 work-hour for an estimated cost of $85 per inspection and up to $4,505 for the U.S. fleet.

Replacing a double bearing would take about 16 work-hours and parts cost about $1,620 for an estimated cost of 2,980 per replacement and $157,940 for the U.S. fleet.

Inspecting the TGB chip detector for particles would take about 1 work-hour for an estimated cost of $85 per inspection and $4,505 for the U.S. fleet.

Performing a double bearing washing would take about 8 work-hours for an estimated cost of $680 per helicopter.

The FAA estimates the following costs to do any necessary on-condition replacements that would be required based on the results of the inspection. The agency has no way of determining the number of aircraft that might need these on-condition replacements:

Analyzing collected particles would take about 1 work-hour for an estimated cost of $85 per helicopter.

Replacing a double bearing would take about 16 work-hours and parts would cost about $1,620 for an estimated cost of $2,980 per bearing.

Replacing a TGB chip detector or TGB electrical magnetic plug would take about 1 work-hour and parts would cost about $900 for an estimated cost of $985 per part replacement.

Replacing an O-ring would take about 1 work-hour and parts would cost about $100 for an estimated cost of $185 per O-ring.

Replacing a TGB would take about 8 work-hours and parts would cost about $155,302 for an estimated cost of $155,982 per replacement.

The FAA has received no definitive data for the repair cost of a TGB.

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-2022-0295; Project Identifier MCAI-2021-00840-R.

(a) Comments Due Date

The FAA must receive comments on this airworthiness directive (AD) by May 26, 2022.

(b) Affected ADs

None.

(c) Applicability

This AD applies to all Airbus Helicopters Model AS-365N2, AS 365 N3, EC 155B, EC155B1, and SA-365N1 helicopters, certificated in any category.

(d) Subject

Joint Aircraft Service Component (JASC) Code 6500, Tail Rotor Drive System.

(e) Unsafe Condition

This AD was prompted by a large amount of critical scale particles found on the tail rotor gearbox (TGB) chip detector magnetic plug during an unscheduled check of the TGB. The particles belonged to the double bearing (pitch control rod bearing) installed inside the TGB. The FAA is issuing this AD to prevent bearing degradation and subsequent failure. The unsafe condition, if not addressed, could result in loss of 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 2021-0170, dated July 19, 2021 (EASA AD 2021-0170).

(h) Exceptions to EASA AD 2021-0170

(1) Where EASA AD 2021-0170 requires compliance in terms of flight hours (FH), this AD requires using hours time-in-service (TIS).

(2) Where EASA AD 2021-0170 refers to the effective dates specified in paragraphs (h)(2)(i) through (iii) of this AD, this AD requires using the effective date of this AD.

(i) October 28, 2019 (the effective date of EASA AD 2019-0267-E, dated October 25, 2019).

(ii) November 19, 2019 (the effective date of EASA AD 2019-0267R1, dated November 12, 2019 and corrected November 13, 2019).

(iii) The effective date of EASA AD 2021-0170.

(3) Where EASA AD 2021-0170 requires actions during each “after last flight (ALF) of the day inspection” or “ALF,” this AD requires those actions before the first flight of each day.

(4) Where paragraph (7) of EASA AD 2021-0170 specifies “any discrepancy,” for this AD discrepancies include the presence of particles and other conditions such as abrasions, particles that consist of any scale, chip, flake, splinter, M50 particles, magnetic abrasion dust, or other particles other than cotter pin fragments, pieces of lock wire, swarf, or miscellaneous non-metallic waste.

(5) Where paragraph (8) of EASA AD 2021-0170 specifies for Group 2 helicopters, the first replacement of the affected part must be accomplished not later than December 31, 2021, this AD requires, for Group 2 helicopters, the first replacement of the affected part as defined in EASA AD 2021-0170 must be accomplished within 5 months after the effective date of this AD.

(6) Where any work card referenced in the service information referenced in EASA AD 2021-0170 specifies “if there is an anomaly, replace the chip detector,” or “if there is an anomaly, replace the TGB electrical magnetic plug,” for this AD an anomaly may be indicated by the magnetic component of the TGB chip detector or the TGB electrical magnetic plug not being magnetized. If there is an anomaly, this AD requires before further flight, removing from service the TGB chip detector or the TGB electrical magnetic plug as applicable to your model helicopter.

(7) Where any work card referenced in the service information referenced in EASA AD 2021-0170 specifies “make sure that the chip detector is in good condition,” or “make sure that the TGB electrical magnetic plug is in good condition,” as applicable to your model helicopter, for this AD “good condition” is indicated when there are no signs of wear on the locking systems (including wear on the bayonets, and slotted tubes). If there are any signs of wear on the locking systems, this AD requires before further flight, removing from service the TGB chip detector or the TGB magnetic electrical magnetic plug as applicable to your model helicopter.

(8) Where any work card referenced in the service information referenced in EASA AD 2021-0170 specifies “if necessary, replace the O-rings,” this AD requires before further flight, removing any affected O-ring from service.

(9) Where the service information referenced in EASA AD 2021-0170 specifies to return certain parts to the manufacturer, including for repair, this AD does not require returning parts to the manufacturer, however, this AD does require before further flight, repair done in accordance with a method approved by the Manager, General Aviation and Rotorcraft Section, International Validation Branch, FAA; or EASA; or Airbus Helicopters' EASA Design Organization Approval (DOA). If approved by the DOA, the approval must include the DOA-authorized signature.

(10) Where the service information referenced in EASA AD 2021-0170 specifies to remove the TGB as per technical documentation, or remove the concerned module(s), this AD requires before further flight, removing the TGB and replacing it with an airworthy part, or repairing the TGB in accordance with a method approved by the Manager, General Aviation & Rotorcraft Section, International Validation Branch, FAA; or EASA; or Airbus Helicopters' EASA DOA. If approved by the DOA, the approval must include the DOA-authorized signature.

(11) Where the service information referenced in EASA AD 2021-0170 specifies if the collected particles cannot be clearly defined, perform a metallurgical analysis and contact Airbus Helicopters, before continuing flights, this AD does require before further flight, characterization of the particles collected, and performing a metallurgical analysis for any particles collected using a method in accordance with FAA-approved procedures. However, this AD does not require contacting the manufacturer to determine the characterization of the particles collected.

(12) Where the service information or any work card referenced in EASA AD 2021-0170 specifies to do the actions identified in paragraphs (h)(12)(i) through (v) of this AD, this AD does not include those requirements.

(i) Complete Appendix 4.A and 4.B.

(ii) Comply with paragraph 2.D.

(iii) Send all collected particles and metallurgical analysis report to depot level maintenance facility with the concerned module.

(iv) Inform EST using chip detection tracking sheet.

(v) Complete the “Particle Detection” follow up sheet.

(13) Where a work card referenced in the service information referenced in EASA AD 2021-0170 specifies “send all oversized particles for analysis and wait for results before continuing flight,” this AD does not require sending particles for analysis, however this AD does require before further flight, analyzing the particles using a method in accordance with FAA-approved procedures.

(14) This AD does not mandate compliance with the “Remarks” section of EASA AD 2021-0170.

(15) Where paragraph (7) of EASA AD 2021-0170 specifies to accomplish the applicable corrective actions “within the compliance time as identified in the applicable ASB,” this AD requires accomplishing corrective actions before further flight.

(16) Where paragraph (1) of EASA AD 2021-0170 specifies “within the applicable compliance time as identified in the close monitoring and until completion of the close monitoring,” this AD requires a close monitoring compliance time of a total of 25 hours TIS.

(i) No Reporting Requirement

Although the service information referenced in EASA AD 2021-0170 specifies to submit certain information to the manufacturer, this AD does not include that requirement.

(j) Special Flight Permit

Special flight permits may be issued in accordance with 14 CFR 21.197 and 21.199, provided no passengers are onboard.

(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: 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

(1) For EASA AD 2021-0170, contact EASA, Konrad-Adenauer-Ufer 3, 50668 Cologne, Germany; telephone +49 221 8999 000; email ADs@easa.europa.eu; 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 (817) 222-5110. This material may be found in the AD docket at https://www.regulations.gov by searching for and locating Docket No. FAA-2022-0295.

(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 (516) 228-7330; email andrea.jimenez@faa.gov.