AD 2018-18-11

This AD is effective October 18, 2018.

The Director of the Federal Register approved the incorporation by reference of a certain document listed in this AD as of October 18, 2018.

For service information identified in this final 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 http://www.helicopters.airbus.com/website/en/ref/Technical-Support_73.html. You may review the referenced service information at the FAA, Office of the Regional Counsel, Southwest Region, 10101 Hillwood Pkwy., Room 6N-321, Fort Worth, TX 76177. It is also available on the internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2018-0418.

George Schwab, Aviation Safety Engineer, Safety Management Section, Rotorcraft Standards Branch, FAA, 10101 Hillwood Pkwy., Fort Worth, TX 76177; telephone (817) 222-5110; email george.schwab@faa.gov.

On May 11, 2018, at 83 FR 21964, the Federal Register published our notice of proposed rulemaking (NPRM), which proposed to amend 14 CFR part 39 by adding an AD that would apply to Airbus Helicopters Model AS-365N2 and AS 365 N3 helicopters with a lower strobe light installed.

The NPRM proposed to require installing a cable mount on the helicopter structure and inspecting the lower strobe light electrical harness and the electrical harness between the cut-off connector and Frame 2000 for torn spiral tape and for any chafing on the harness cables. If the spiral tape is torn, the NPRM proposed to require replacing the spiral tape. If there is any chafing on the cable, the NPRM proposed to require replacing the harness. The proposed requirements were intended to prevent interference between the lower strobe light electrical harness wiring and the helicopter structure, which could result in chafing of an electrical harness adjacent to the inboard fuel tank vapor space, a fuel tank fire, and subsequent loss of control of the helicopter.

The NPRM was prompted by AD No. 2016-0258, dated December 16, 2016, issued by EASA, which is the Technical Agent for the Member States of the European Union, to correct an unsafe condition for Airbus Helicopters Model AS 365 N2 and AS 365 N3 helicopters with certain serial numbers and configurations. EASA advises of in-production helicopters with lower strobe light wiring harnesses that were interfering with either the helicopter structure or the adjacent fuel tank support. EASA further states that an investigation determined that the electrical harnesses of these lower strobe lights were manufactured with additional length to facilitate removal and installation of the lower strobe light assembly. However, the additional length of wiring in the harness was not properly secured to the helicopter structure. According to EASA, this could result in chafing of the harness on the helicopter structure, creating an ignition source adjacent to the inboard fuel tank vapor space, and result in a fuel tank fire.

To address this unsafe condition, the EASA AD requires installing a cable mount, inspecting the lower strobe light electrical harness for damage, and re-routing the electrical harness.

We gave the public the opportunity to participate in developing this AD, but we did not receive any comments on the NPRM.

These helicopters have been approved by the aviation authority of France and are approved for operation in the United States. Pursuant to our bilateral agreement with France, EASA, its technical representative, has notified us of the unsafe condition described in the EASA AD. We are issuing this AD because we evaluated all information provided by EASA and determined the unsafe condition exists and is likely to exist or develop on other helicopters of these same type designs and that air safety and the public interest require adopting the AD requirements as proposed.

The EASA AD limits the applicability to helicopters with a lower strobe light installed and with certain serial numbers or that are in a configuration based upon a modification, service information, or engineering drawings. This AD applies to all Model AS-365N2 and AS 365 N3 helicopters with a lower strobe light installed.

We reviewed Airbus Helicopters Alert Service Bulletin No. AS365-05.00.73, Revision 1, dated December 12, 2016, which specifies procedures for inspecting the lower strobe light electrical harness for interference and chafing with the helicopter structure and also specifies procedures for installing a cable mount to secure the electrical harness. These procedures correspond to Airbus Helicopters modification (MOD) 365P084778.00.

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.

We estimate that this AD affects 30 helicopters of U.S. Registry. We estimate that operators may incur the following costs in order to comply with this AD.

At an average labor rate of $85 per work-hour, installing a cable mount and inspecting the strobe light wiring harnesses requires about 1 work-hour, and required parts cost about $50, for a cost of $135 per helicopter and a total cost of $4,050 to all U.S. operators.

If required, replacing torn spiral tape requires about 1 work-hour, and required parts cost $45, for a cost of $130 per helicopter.

If required, replacing a chafed wiring harness between the cut-off connector and Frame 2000 requires about 3 work-hours, and required parts cost $90, for a cost of $345 per helicopter.

If required, replacing a chafed lower strobe light wiring harness requires about 3 work-hours, and required parts cost $154, for a cost of $409 per helicopter.

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.

We are 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 helicopters identified in this rulemaking action.

This AD will not have federalism implications under Executive Order 13132. This AD will 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 that this AD:

(1) Is not a “significant regulatory action” under Executive Order 12866;

(2) Is not a “significant rule” under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979);

(3) Will not affect intrastate aviation in Alaska to the extent that it justifies making a regulatory distinction; and

(4) 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.

We prepared an economic evaluation of the estimated costs to comply with this AD and placed it in the AD docket.

Accordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows:

1. The authority citation for part 39 continues to read as follows:

2. The FAA amends § 39.13 by adding the following new airworthiness directive (AD):