2021-07623. Airworthiness Directives; Airbus Helicopters Deutschland GmbH 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 Airbus Helicopters Deutschland GmbH (Airbus Helicopters) Model EC135P1, EC135P2, EC135P2+, EC135P3, EC135T1, EC135T2, EC135T2+, and EC135T3 helicopters. This proposed AD would require modification of the tail rotor (T/R) control installation, a functional test, and corrective actions as necessary. This proposed AD is prompted by cases of insufficient clearance between a certain T/R control bearing connection and the helicopter structure, which were detected on the production line. The FAA is proposing this AD to address an unsafe condition on these products.

DATES:

The FAA must receive comments on this proposed AD by June 1, 2021.

ADDRESSES:

You may send comments by any of the following methods:

• Federal eRulemaking Docket: Go to https://www.regulations.gov. Follow the online instructions for sending your comments electronically.
• Fax: [phone].
• Mail: Send comments to the U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590-0001.
• Hand Delivery: Deliver to the “Mail” address between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

For service information identified in this NPRM, contact Airbus Helicopters, 2701 N Forum Drive, Grand Prairie, TX 75052; telephone [phone] or 800-232-0323; fax [phone]; or at https://www.airbus.com/​helicopters/​services/​technical-support.html. You may view the referenced service information at the FAA, Office of the Regional Counsel, Southwest Region, 10101 Hillwood Pkwy., Room 6N-321, Fort Worth, TX 76177.

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-2019-0293; 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 European Aviation Safety Agency (EASA) AD, any comments received, and other information. The street address for Docket Operations is listed above.

FOR FURTHER INFORMATION CONTACT:

David Hatfield, Aviation Safety Engineer, Aircraft Systems Section, Technical Innovation Policy Branch, FAA, 10101 Hillwood Pkwy., Fort Worth, TX 76177; 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-2019-0293; Product Identifier 2017-SW-052-AD” 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 David Hatfield, Aviation Safety Engineer, Aircraft Systems Section, Technical Innovation Policy Branch, FAA, 10101 Hill wood Pkwy., Fort Worth, TX 76177; telephone [phone]; email [e-mail]. 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 2017-0147, dated August 10, 2017 (EASA AD 2017-0147), to correct an unsafe condition for Airbus Helicopters Model EC135P1, EC135P2, EC135P2+, EC135P3, EC135T1, EC135T2, EC135T2+, EC135T3, EC635P2+, EC635P3, EC635T1, EC635T2+, and EC635T3 helicopters. EASA advises that several cases of insufficient clearance between a certain T/R bearing connection and the helicopter structure were detected during inspections of helicopters on the production line. EASA states that this condition, if not corrected and in the case of an unglued bearing, could lead to blockage of the pedal controlling the T/R thrust and loss of the T/R control. EASA further advises that this could result in a forced landing with damage to the helicopter and injury to the occupants.

Accordingly, EASA AD 2017-0147 requires modifying the T/R control installation by adding a Teflon washer, which reduces the degree of freedom in case of a drifting bearing at the affected connection. EASA AD 2017-0147 also requires a functional test for clearance, and depending on the results, either accomplishing additional corrective actions or contacting Airbus Helicopters for instructions.

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 issuing this NPRM after determining that an unsafe condition described previously is likely to exist or develop on other helicopters of the same type designs.

Related Service Information Under 1 CFR Part 51

The FAA reviewed Airbus Helicopters Alert Service Bulletin EC135-67A-031, Revision 0, dated March 30, 2017 (ASB EC135-67A-031), for Airbus Helicopters Model EC135P1, EC135P2, EC135P2+, EC135P3, EC135T1, EC135T2, EC135T2+, EC135T3, EC635P2+, EC635P3, EC635T1, EC635T2+, and EC635T3 helicopters. For serial numbers (S/N) up to 1254 inclusive, except S/N 1235, this service information specifies retrofitting a Teflon washer on the T/R controls, performing a functional test of the modified T/R control installation to inspect for clearance, and making any necessary adjustments. This service information advises that S/N 1255 and up will have the Teflon washer installed in production.

This service information 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.

Proposed AD Requirements in This NPRM

This proposed AD would apply to Model EC135P1, EC135P2, EC135P2+, EC135P3, EC135T1, EC125T2+, and EC135T3 helicopters with a S/N up to 1254 inclusive (except for S/N 1235) and would require modifying the T/R control within 360 hours time-in-service (TIS) by installing a Teflon washer and performing a functional test in accordance with specified portions of ASB EC135-67A-031. Based on the results of the functional test, this proposed AD would require making repairs in accordance with FAA-approved procedures.

Differences Between This Proposed AD and the EASA AD

The EASA AD sets compliance times at 12 months, while this proposed AD would require compliance within 360 hours TIS. The EASA AD applies to Airbus Helicopters Model 635 T1, 635 T2+, 635 T3, 635 P2+, 635 P3 helicopters, and this proposed AD would not because those models do not have an FAA type certificate. The EASA AD requires contacting Airbus Helicopters for approved repair procedures, while this proposed AD would require a repair using FAA-approved procedures. The EASA AD requires revising the “aircraft maintenance program,” whereas this AD does not because not all U.S. operators are required to have a maintenance program.

Costs of Compliance

The FAA estimates that this AD, if adopted as proposed, would affect 331 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.

Modifying the T/R control installation and conducting a functional test would take about 3 work-hours and parts would cost about $25 for an estimated cost of $280 per helicopter and $92,680 for the U.S. fleet.

If required, adjusting the clearance would take about 1 work-hour for an estimated cost of $85 per helicopter.

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, I certify this proposed regulation:

1. Is not a “significant regulatory action” under Executive Order 12866,

2. Will not affect intrastate aviation in Alaska, and

3. Will 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 Deutschland GmbH: Docket No. FAA-2019-0293; Product Identifier 2017-SW-052-AD.

(a) Comments Due Date

The FAA must receive comments on this airworthiness directive (AD) by June 1, 2021.

(b) Affected ADs

None.

(c) Applicability

This AD applies to Airbus Helicopters Deutschland GmbH Model EC135P1, EC135P2, EC135P2+, EC135P3, EC135T1, EC135T2, EC135T2+, and EC135T3 helicopters with serial number (S/N) up to and including 1254 (except S/N 1235), certificated in any category.

(d) Subject

Joint Aircraft Service Component (JASC) Code: 6720, Tail Rotor Control System.

(e) Unsafe Condition

This AD defines the unsafe condition as interference between the tail rotor (T/R) control bearing connection close-tolerance bolt and the helicopter structure, which could lead to blockage of the pedal controlling the T/R thrust. This condition could result in loss of T/R control, prompting a forced landing.

(f) Compliance

Comply with this AD within the compliance times specified, unless already done.

(g) Required Actions

Within 360 hours time-in-service, modify the T/R control by installing a Teflon washer and perform a functional test of the modification in accordance with the Accomplishment Instructions, paragraphs 3.B.2 through 3.B.4.2., of Airbus Helicopters Alert Service Bulletin ASB EC135-67A-031, Revision 0, dated March 30, 2017. If, during the functional test, the clearance between the end of the close‐tolerance bolt, castellated nut, and the lower stringer is less than 1.0 mm, repair in accordance with FAA-approved procedures.

(h) Alternative Methods of Compliance (AMOCs)

(1) The Manager, International Validation Branch, 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. 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.

(i) Related Information

(1) For more information about this AD, contact David Hatfield, Aviation Safety Engineer, Aircraft Systems Section, Technical Innovation Policy Branch, FAA, 10101 Hillwood Pkwy., Fort Worth, TX 76177; telephone [phone]; email [e-mail].

(2) For service information identified in this AD, contact Airbus Helicopters, 2701 N Forum Drive, Grand Prairie, TX 75052; telephone [phone] or 800-232-0323; fax [phone]; or at https://www.airbus.com/​helicopters/​services/​technical-support.html. You may view the referenced service information at the FAA, Office of the Regional Counsel, Southwest Region, 10101 Hillwood Pkwy., Room 6N-321, Fort Worth, TX 76177.

(3) The subject of this AD is addressed in European Aviation Safety Agency (EASA) AD 2017-0147, dated August 10, 2017. You may view the EASA AD on the internet at https://www.regulations.gov in the AD Docket.

Issued on April 8, 2021.

Lance T. Gant,

Director, Compliance & Airworthiness Division, Aircraft Certification Service.