Airworthiness Directives; Airbus Helicopters

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to supersede Airworthiness Directive (AD) 2016-08-20 for certain Airbus Helicopters (previously Eurocopter France) EC130B4 and EC130T2 helicopters. AD 2016-08-20 requires repetitively inspecting the tail boom to Fenestron junction frame (junction frame) for a crack. Since the FAA issued AD 2016-08-20, additional cracks have been reported and a design change that modifies the junction frame has become available. This proposed AD would continue to require inspecting the junction frame with the horizontal stabilizer removed, and would propose to expand the applicability, revise the compliance time and the inspection procedures for inspecting the junction frame, add inspection procedures for certain helicopters, allow repair of the junction frame, and would require modifying and then repetitively inspecting the junction frame and reporting certain information. The actions of this proposed AD are intended to address an unsafe condition on these products.

DATES:

The FAA must receive comments on this proposed AD by April 5, 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: 202-493-2251.
• 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.

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-2020-1182; 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 proposed AD, the European Aviation Safety Agency (now European Union Aviation Safety Agency) (EASA) AD, 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 service information identified in this proposed rule, contact Airbus Helicopters, 2701 N. Forum Drive, Grand Prairie, TX 75052; telephone 972-641-0000 or 800-232-0323; fax 972-641-3775; 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.

FOR FURTHER INFORMATION CONTACT:

Kristi Bradley, Aviation Safety Engineer, General Aviation & Rotorcraft Section, International Validation Branch, FAA, 10101 Hillwood Pkwy., Fort Worth, TX 76177; telephone 817-222-5110; email kristin.bradley@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-2020-1182; Product Identifier 2018-SW-036-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.

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 Kristi Bradley, Aviation Safety Engineer, General Aviation & Rotorcraft Section, International Validation Branch, FAA, 10101 Hillwood Pkwy., Fort Worth, TX 76177; telephone 817-222-5110; email kristin.bradley@faa.gov. Any commentary that the FAA receives which is not specifically designated as CBI will be placed in the public docket for this rulemaking.

Discussion

The FAA issued AD 2016-08-20, Amendment 39-18497 (81 FR 26103, May 2, 2016) (2016-08-20), for Airbus Helicopters Model EC130B4 and EC130T2 helicopters with a junction frame that has 690 or more hours time-in-service (TIS) installed. AD 2016-08-20 requires dye penetrant and borescope inspecting around the circumference of the junction frame for a crack and replacing any cracked junction frame. AD 2016-08-20 was prompted by EASA AD 2015-0033-E, dated February 24, 2015 (EASA AD 2015-0033-E), issued by EASA, which is the Technical Agent for the Member States of the European Union, to supersede an existing EASA AD. EASA had determined that it was necessary to define an inspection interval in sling cycles in addition to the existing flight hour inspection interval. EASA also acknowledged an alternative method to inspect from the outside of the tail boom.

Actions Since AD 2016-08-20 Was Issued

Since the FAA issued AD 2016-08-20, EASA has issued a series of ADs, the most recent being EASA AD 2018-0104, dated May 4, 2018 (EASA AD 2018-0104), to correct an unsafe condition for Airbus Helicopters (formerly Eurocopter, Eurocopter France) Model EC 130 B4 and EC 130 T2 helicopters, all serial numbers, except those with Airbus modification (MOD) 074775 installed. EASA's initial AD was prompted by two incidents of crack propagation through the junction frame that initiated in the lower right-hand side between the web and the flange where the lower spar of the tail boom is joined. EASA states the cracks were of a significant length and not visible from the outside of the helicopter. EASA advised that this condition, if not detected, could lead to structural failure, possibly resulting in Fenestron detachment and consequent loss of control of the helicopter.

Following EASA AD 2015-0033-E, EASA revised its AD to EASA AD 2015-0033R1, dated May 3, 2016 (EASA AD 2015-0033R1), which was prompted by the determination that it was not necessary to inspect junction frames that had accumulated less than 1,200 flight hours. Accordingly, EASA AD 2015-0033R1 extended the inspection threshold from 700 flight hours to 1,200 flight hours. Thereafter, EASA issued EASA AD 2016-0240, dated December 2, 2016 (EASA AD 2016-0240) to supersede EASA AD 2015-0033R1. EASA AD 2016-0240 was prompted by a third incident of cracking in the same area of the junction frame as the first two incidents. Investigation determined that detection of the crack was delayed because of insufficient cleaning of the inspection area inside the junction frame. For that reason, EASA AD 2016-0240 retained the requirements of EASA AD 2015-0033R1 and added additional cleaning requirements before inspecting. After EASA AD 2016-0240 was issued, a fourth incident of cracking in the same area of the junction frame as the first three incidents was reported. This fourth incident prompted EASA to issue EASA AD 2017-0066-E, dated April 21, 2017 (EASA AD 2017-0066-E) to supersede EASA AD 2016-0240. This fourth incident occurred on a junction frame that had accumulated significantly less flight hours than the first three incidents. In light of this, EASA AD 2017-0066-E retained the requirements of EASA AD 2016-0240 and reduced the inspection threshold. Shortly after, EASA issued EASA AD 2017-0080, dated May 5, 2017 (EASA AD 2017-0080) to supersede EASA AD 2017-0066-E. EASA AD 2017-0080 was prompted by the determination that improved procedures to remove the horizontal stabilizer before cleaning and inspecting were necessary for certain helicopters. Accordingly, EASA AD 2017-0080 retained the requirements of EASA AD 2017-0066-E and added the improved procedures. Since EASA issued EASA AD 2017-0080, Airbus Helicopters developed MOD 074775, which consists of the installation of four carbon patches at the junction frame. Installation of MOD 074775, either in production or by retrofit, constitutes terminating action for the repetitive inspections. Based on the latest information, EASA determined that continued inspections may not adequately address the long-term risk and requires modifying the affected helicopters, which also terminates the repetitive inspections of the pre-modified configuration. Accordingly, EASA issued EASA AD 2018-0104 to supersede EASA AD 2017-0080 to require installation of MOD 074775.

Also since the FAA issued AD 2016-08-20, it has been determined that the dye penetrant inspections required by AD 2016-08-20 are unnecessary because visual inspections are adequate to inspect for cracks in the affected area instead.

As a result of the EASA-issued ADs and the further incidents of cracked junction frames, this proposed AD proposes to expand the applicability to include all Airbus Helicopters Model EC130B4 and EC130T2 helicopters with a junction frame, regardless of how many hours TIS have accumulated on the junction frame; revise the compliance time to inspect the junction frame with the horizontal stabilizer removed to depend on the hours TIS accumulated on the junction frame; change the inspection of the junction frame with the horizontal stabilizer removed from the dye-penetrant inspection required by AD 2016-08-20 to a visual inspection; add inspection procedures for helicopters with a skin cut-out at the junction frame; allow repairing a junction frame in accordance with an FAA approved repair procedure; require the installation of MOD 074775 or the four carbon patches reinforcements; and require repetitive inspections of a modified junction frame.

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 of the unsafe condition described in its AD. The FAA is proposing this AD after evaluating all of the information provided by EASA and determining the unsafe condition exists and is likely to exist or develop on other helicopters of these same type designs.

Related Service Information Under 1 CFR Part 51

Airbus Helicopters has issued Emergency Alert Service Bulletin No. 05A017, Revision 7, dated March 21, 2018, for Model EC130 B4 and T2 helicopters without MOD 074775 installed. This service information specifies procedures for cleaning inside the junction frame, inspecting the junction frame from the inside of the tail boom with the horizontal stabilizer both removed and installed for a crack, and inspecting the junction frame from the outside of the tail boom for a crack.

Airbus Helicopters has issued Service Bulletin No. EC130-53-036, Revision 4, dated April, 28, 2020, for Model EC130 B4 and T2 helicopters without MOD 074609 or 074775 installed and on which the skin of the junction frame area has not been repaired. This service information specifies procedures to reinforce the junction frame (MOD 074775) by replacing the two lateral splices which join the skins with four carbon patches (left-hand side, right-hand side, and lower sides).

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.

Other Related Service Information

Airbus Helicopters has issued Service Bulletin No. EC130-53-029, Revision 1, dated January 27, 2016. This service information specifies procedures to make a cut-out of the splice and skin at the junction frame (MOD 350A087421).

Airbus has issued EC 130 B4 Chapter 4, Airworthiness Limitations Section, Revision 11, dated January 19, 2019 and EC 130 T2 Chapter 4, Airworthiness Limitations Section, Revision 9, dated September 9, 2019, which specify visually checking the junction frame for cracks at an interval of 600 flight hours with a margin of 60 flight hours.

Airbus Helicopters has also issued Section 55-11-00, 6-4—Horizontal Stabilizer—Inspection/Check, of Aircraft Maintenance Manual EC130, dated November 9, 2017, which specifies procedures for cleaning inside the junction frame and inspecting the junction frame from the inside of the tail boom with the horizontal stabilizer removed.

Proposed AD Requirements

This proposed AD would require:

• For helicopters without MOD 074775, or MOD AH 350A087421 or SB EC130-53-029 installed, at a compliance time based on the hours TIS accumulated on the junction frame, removing the horizontal stabilizer, cleaning the junction frame, and visually inspecting the junction frame area for a crack, paying particular attention to the area around the 4 spars.

○ Following the initial visual inspection, within 25 hours TIS or 390 sling cycles, whichever comes first, and thereafter at intervals not exceeding 25 hours TIS or 390 sling cycles, whichever comes first, either repeating the initial visual inspection, or, if the surface area is clean, borescope inspecting the junction frame area for a crack, paying particular attention to the area around the 4 spars.

○ Also following the initial visual inspection, within 150 hours TIS and thereafter at intervals not to exceed 150 hours TIS, repeating the initial visual inspection.

• For helicopters without MOD 074775 installed, but with MOD AH 350A087421 or SB EC130-53-029 installed, before the junction frame accumulates 350 hours TIS or within 10 hours TIS, whichever occurs later, visually inspecting for a crack on the junction frame area in each skin cut-out area.

○ Following the initial visual inspection, within 10 hours TIS or 250 sling cycles, whichever occurs first, and thereafter at intervals not exceeding 10 hours TIS or 250 sling cycles, whichever occurs first, repeating the initial visual inspection.

○ Also following the initial visual inspection, within 660 hours TIS and thereafter at intervals not to exceed 660 hours TIS, removing the horizontal stabilizer, cleaning the junction frame, and dye-penetrant inspecting the junction frame area for a crack, paying particular attention to the area around the 4 spars.

• If there is a crack, replacing or repairing the junction frame in accordance with an FAA approved repair procedure before further flight. Repairing the junction frame would not constitute terminating action for the requirements of this proposed AD.
• For helicopters without MOD 074775 installed, with or without MOD AH 350A087421 or SB EC130-53-029 installed, without MOD 074609 or SB 53-024 installed, and on which the skin of the junction frame area has never been repaired, installing MOD 074775 within 24 months as of the effective date of this AD and reporting certain information to Airbus Helicopters within 30 days after installing MOD 074775.
• For helicopters without MOD 074775 installed, with MOD 074609 or SB 53-024 installed, or on which the skin of the junction frame area has been previously repaired at any time, reinforcing the junction frame by replacing the two lateral splices which join the skins with four carbon patches (left-hand side, right-hand side, and lower sides) within 24 months as of the effective date of this AD.
• For helicopters with MOD 074775 installed or with the four carbon patches reinforcements installed, but without MOD 074581 for Model EC130T2 helicopters, within 600 hours TIS after the installation of MOD 074775 or the reinforcement, and thereafter at intervals not exceeding 600 hours TIS, visually inspect the junction frame area for a crack. If there is a crack, replacing or repairing the junction frame in accordance with an FAA approved repair procedure before further flight. Repairing the junction frame would not constitute terminating action for the requirements of this proposed AD.

Differences Between This Proposed AD and the EASA AD

EASA AD 2018-0104 does not apply to helicopters with MOD 074775, whereas this proposed AD does. EASA AD 2018-0104 requires performing a local non-destructive inspection if in doubt about if there is a crack, whereas this proposed AD does not. EASA AD 2018-0104 allows the pilot to visually inspect the junction frame from outside the tail boom for a crack, whereas this proposed AD does not. EASA AD 2018-0104 requires contacting Airbus Helicopters if any crack is detected, whereas this proposed AD would require replacing or repairing the junction frame in accordance with an FAA approved repair procedure instead. This proposed AD would require a repetitive inspection for helicopters with MOD 074775 installed, whereas the EASA AD does not.

Costs of Compliance

The FAA estimates that this proposed AD affects 263 helicopters of U.S. Registry. Labor costs are estimated at $85 per work-hours. Based on these numbers, the FAA estimates that operators may incur the following costs in order to comply with this proposed AD.

Cleaning and inspecting the junction frame area with the horizontal stabilizer removed would take about 1 work-hour for an estimated cost of $85 per helicopter and $22,355 for the U.S. fleet, per inspection cycle.

Internally borescope inspecting the junction frame area with the horizontal stabilizer installed would take about 0.5 work hour for an estimated cost of $43 per helicopter and $11,309 for the U.S. fleet, per inspection cycle.

If applicable, cleaning and inspecting the junction frame area in each skin cut-out area would take about 1.25 work-hour for an estimated cost of $106 per helicopter and $27,878 for the U.S. fleet, per inspection cycle.

Modifying the junction frame skin reinforcements would take about 90 work-hours and parts cost about $10,000 for an estimated cost of $17,650 per helicopter and $4,641,950 for the U.S. fleet. Reporting certain information would take about 1 work-hour for an estimated cost of $85 per helicopter and $22,355 for the U.S. fleet. Inspecting the modified junction frame area would take about 1 work-hour for an estimated cost of $85 per helicopter and $22,355 for the U.S. fleet, per inspection cycle.

If required, repairing or replacing the junction frame would take up to 50 work-hours and parts would cost about $60,000 for an estimated cost of $64,250 per helicopter.

According to Airbus Helicopters' service information, some of the costs of this proposed AD may be covered under warranty, thereby reducing the cost impact on affected individuals. The FAA does not control warranty coverage by Airbus Helicopters. Accordingly, the FAA has included all costs in this cost estimate.

Paperwork Reduction Act

A federal agency may not conduct or sponsor, and a person is not required to respond to, nor shall a person be subject to penalty for failure to comply with a collection of information subject to the requirements of the Paperwork Reduction Act unless that collection of information displays a current valid OMB Control Number. The OMB Control Number for this information collection is 2120-0056. Public reporting for this collection of information is estimated to be approximately 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. All responses to this collection of information are mandatory. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to: Information Collection Clearance Officer, Federal Aviation Administration, 10101 Hillwood Parkway, Fort Worth, TX 76177-1524.

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 that 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.

2. The FAA amends § 39.13 by:

a. Removing Airworthiness Directive (AD) 2016-08-20, Amendment 39-18497 ( 81 FR 26103, May 2, 2016); and

b. Adding the following new AD:

Airbus Helicopters: Docket No. FAA-2020-1182; Product Identifier 2018-SW-036-AD.

(a) Applicability

This airworthiness directive (AD) applies to Airbus Helicopters Model EC130B4 and EC130T2 helicopters, certificated in any category, with a tail boom to Fenestron junction frame (junction frame).

(b) Unsafe Condition

This AD defines the unsafe condition as a crack in the junction frame. This condition could result in failure of the junction frame, which could result in loss of the Fenestron and subsequent loss of control of the helicopter.

(c) Affected ADs

This AD supersedes AD 2016-08-20, Amendment 39-18497 (81 FR 26103, May 2, 2016).

(d) Comments Due Date

The FAA must receive comments by April 5, 2021.

(e) Compliance

You are responsible for performing each action required by this AD within the specified compliance time unless it has already been accomplished prior to that time.

(f) Required Actions

(1) For helicopters without modification (MOD) 074775, or MOD AH 350A087421 or SB EC130-53-029 installed, at the compliance time specified by the hours time-in-service (TIS) accumulated on the junction frame in Figure 1 to this paragraph, do the following:

(i) Remove the horizontal stabilizer; using a clean, lint-free, white cloth soaked with liquid Methyl Ethyl Ketone (MEK), clean the inside of the junction frame (a) as shown in Figure 1 of Airbus Helicopters Emergency Alert Service Bulletin No. 05A017, Revision 7, dated March 21, 2018 (EASB 05A017, Rev 7); and visually inspect for cracking around the circumference of the junction frame, in the web of the junction frame (a) and in the radius between the web and the flange of the tail boom side as shown in Figure 1 EASB 05A017, Rev 7. Pay particular attention to the area around the 4 spars (b) as shown in Figure 1 of EASB 05A017, Rev 7. Examples of cracks are shown in Figure 3 of EASB 05A017, Rev 7. If there is a crack, before further flight, replace or repair the junction frame in accordance with an FAA approved repair procedure. Repairing or replacing the junction frame does not constitute terminating action for the requirements of this AD.

(ii) Thereafter following paragraph (f)(1)(i) of this AD, within 25 hours TIS or 390 sling cycles for helicopters that perform external load carrying operations, whichever occurs first, and thereafter at intervals not exceeding 25 hours TIS or 390 sling cycles, whichever occurs first, either perform the actions of paragraph (f)(1)(i) of this AD or, if the surface of the junction frame area is clean, use a borescope through the horizontal stabilizer opening to borescope inspect for a crack around the circumference of the junction frame, and in the web of the junction frame (a) and in the radius between the web and the flange on the tail boom side as shown in Figure 2 EASB 05A017, Rev 7. Pay particular attention to the area around the 4 spars (b) of Figure 2 of EASB 05A017, Rev 7. Examples of cracks are shown in Figure 3 of EASB 05A017, Rev 7. For purposes of this AD, a sling cycle is defined as one landing with or without stopping the rotor or one external load-carrying operation; an external load-carrying operation occurs each time a helicopter picks up an external load and drops it off. If there is a crack, before further flight, replace or repair the junction frame in accordance with an FAA approved repair procedure. Repairing or replacing the junction frame does not constitute terminating action for the requirements of this AD.

(iii) Thereafter following paragraph (f)(1)(i) of this AD, within 150 hours TIS and thereafter at intervals not to exceed 150 hours TIS, accomplish the actions required by paragraph (f)(1)(i) of this AD. Accomplishment of this paragraph constitutes compliance for an instance of paragraph (f)(1)(ii) of this AD.

(2) For helicopters without MOD 074775 installed, but with MOD AH 350A087421 or SB EC130-53-029 installed, before the junction frame accumulates 350 hours TIS or within 10 hours TIS, whichever occurs later:

(i) Visually inspect for cracking on the junction frame (a) in the upper and lower right-hand side and upper and lower left-hand side areas of the skin cut-out as shown in Detail A, Figure 4 of EASB 05A017, Rev 7. If there is a crack, before further flight, replace or repair the junction frame in accordance with an FAA approved repair procedure. Repairing or replacing the junction frame does not constitute terminating action for the requirements of this AD.

(ii) Thereafter following paragraph (f)(2)(i) of this AD, within 10 hours TIS or 250 sling cycles for helicopters that perform external load carrying operations, whichever occurs first, and thereafter at intervals not exceeding 10 hours TIS or 250 sling cycles, whichever occurs first, accomplish the actions required by paragraph (f)(2)(i) of this AD.

(iii) Thereafter following paragraph (f)(2)(i) of this AD, within 660 hours TIS and thereafter at intervals not to exceed 660 hours TIS, accomplish the actions required by paragraph (f)(1)(i) of this AD. Accomplishment of this paragraph constitutes compliance for an instance of paragraph (f)(2)(ii) of this AD.

(3) For helicopters without MOD 074775 installed, with or without MOD AH 350A087421 or SB EC130-53-029 installed, without MOD 074609 or SB 53-024 installed, and on which the skin of the junction frame area has never been repaired, within 24 months as of the effective date of this AD, install MOD 074775 by following the Accomplishment Instructions, paragraphs 3.B.2.a. through g., of Airbus Helicopters Service Bulletin No. EC130-53-036, Revision 4, dated April, 28, 2020 (ASB EC130-53-036, Rev 4), except where ASB EC130-53-036, Rev. 4 specifies to certain discard parts, you are required to remove those parts from service instead and where ASB EC130-53-036, Rev 4. specifies contacting Airbus Helicopters for corrective action, the corrective action must be accomplished using a method approved by the FAA. Where ASB EC130-53-036, Rev 4, specifies completing the table in Appendix 4.H. under paragraph 3.B.2.g., complete and return the table to Airbus Helicopters within 30 days after installing MOD 074775. Installation of MOD 074775 constitutes terminating action for the inspections required by paragraphs (f)(1) and (2) of this AD.

(4) For helicopters without MOD 074775 installed, with MOD 074609 or SB 53-024 installed, or on which the skin of the junction frame area has been previously repaired at any time, within 24 months as of the effective date of this AD, reinforce the junction frame by replacing the two lateral splices which join the skins with four carbon patches (left-hand side, right-hand side, and lower sides) in accordance with an FAA approved corrective procedure. Installation of this reinforcement constitutes terminating action for the inspections required by paragraphs (f)(1) and (2) of this AD.

(5) For Model EC130B4 helicopters with MOD 074775 installed or with the reinforcement that is required by paragraph (f)(4) of this AD; and for Model EC130T2 helicopters with MOD 074775 installed or with the reinforcement that is required by paragraph (f)(4) of this AD, but without MOD 074581 installed:

(i) Within 600 hours TIS after the installation of MOD 074775 or the reinforcement that is required by paragraph (f)(4) of this AD, and thereafter at intervals not exceeding 600 hours TIS, perform the actions of paragraph (f)(1)(i) of this AD.

(ii) If there is a crack, before further flight, replace or repair the junction frame in accordance with an FAA approved repair procedure. Repairing the junction frame does not constitute terminating action for the requirements of this AD.

(g) Special Flight Permits

Special flight permits are prohibited.

(h) Alternative Methods of Compliance (AMOCs)

(1) The Manager, International Validation Branch, FAA, may approve AMOCs for this AD. Send your proposal to: Kristi Bradley, Aviation Safety Engineer, General Aviation & Rotorcraft Section, International Validation Branch, FAA, 10101 Hillwood Pkwy., Fort Worth, TX 76177; telephone 817-222-5110; email kristin.bradley@faa.gov.

(2) For operations conducted under a 14 CFR part 119 operating certificate or under 14 CFR part 91, subpart K, the FAA suggests that you notify your principal inspector, or lacking a principal inspector, the manager of the local flight standards district office or certificate holding district office, before operating any aircraft complying with this AD through an AMOC.

(i) Additional Information

(1) Airbus Helicopters Service Bulletin No. EC130-53-029, Revision 1, dated January 27, 2016, Airbus EC 130 B4 Chapter 4, Airworthiness Limitations Section, Revision 11, dated January 19, 2019, Airbus EC 130 T2 Chapter 4, Airworthiness Limitations Section, Revision 9, dated September 9, 2019, and Section 55-11-00, 6-4-Horizontal Stabilizer—Inspection/Check, of Aircraft Maintenance Manual EC130, dated November 9, 2017, which are not incorporated by reference, contain additional information about the subject of this AD. For service information identified in this AD, contact Airbus Helicopters, 2701 N. Forum Drive, Grand Prairie, TX 75052; telephone 972-641-0000 or 800-232-0323; fax 972-641-3775; or at https://www.airbus.com/helicopters/services/technical-support.html. You may view a copy of the service information at the FAA, Office of the Regional Counsel, Southwest Region, 10101 Hillwood Pkwy., Room 6N-321, Fort Worth, TX 76177.

(2) The subject of this AD is addressed in European Aviation Safety Agency (now European Union Aviation Safety Agency) (EASA) 2018-0104, dated May 4, 2018. You may view the EASA AD on the internet at https://www.regulations.gov by searching for and locating it in Docket No. FAA-2020-1182.

(j) Subject

Joint Aircraft Service Component (JASC) Code: 5302, Rotorcraft Tail Boom.