AD 2016-01-19

This AD is effective February 25, 2016.

For service information identified in this final rule, contact MD Helicopters, Inc., Attn: Customer Support Division, 4555 E. McDowell Rd., Mail Stop M615, Mesa, AZ 85215-9734; telephone 1-800-388-3378; fax 480-346-6813; or at http://www.mdhelicopters.com. You may review a copy of the referenced service information at the FAA, Office of the Regional Counsel, Southwest Region, 10101 Hillwood Pkwy, Room 6N-321, Fort Worth, TX 76177.

Galib Abumeri, Aerospace Engineer, Los Angeles Aircraft Certification Office, Transport Airplane Directorate, FAA, 3960 Paramount Blvd., Lakewood, California 90712, telephone 562-627-5324; email Galib.Abumeri@faa.gov.

On June 9, 2015, at 80 FR 32508, 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 MDHI Model 500N helicopters with a rotating cone assembly part number (P/N) 500N3740-81 installed, and Model 600N helicopters with a rotating cone assembly P/N 500N3740-71 installed. The NPRM proposed to require establishing a life limit of 10,000 hours TIS on these rotating cone assemblies. Although these parts have a life limit of 10,000 hours TIS, they were incorrectly omitted from the Airworthiness Limitation Section of the Rotorcraft Maintenance Manual. Some of the affected parts were sold as spares, while others were installed on new helicopters in production. The proposed requirements were intended to prevent operation of rotating cone assemblies past their life limits, failure of the rotating cone assemblies, loss of directional control, and subsequent loss of control of the helicopter.

Since the NPRM was issued, the FAA Southwest Regional Office has relocated. This AD includes the current physical address of the FAA Southwest Regional Office.

We gave the public the opportunity to participate in developing this AD, but we received no comments on the NPRM (80 FR 32508, June 9, 2015).

We have reviewed the relevant information and determined that an unsafe condition exists and is likely to exist or develop on other products of these same type designs and that air safety and the public interest require adopting the AD requirements as proposed.

MDHI issued Service Bulletin SB500N-046 and SB600N-054 (SB) as a single bulletin on July 9, 2012. The SB calls for a one-time inspection within 100 flight hours to determine the rotating cone assembly's part number on MDHI Model 500N and 600N helicopters. The SB then states the need to correct the component record for certain rotating cone assemblies.

The SB also specifies determining the rotating cone assembly's total service time since new and recording this on the component record. MDHI reports that failure to comply with the SB may result in an aircraft exceeding the life limit of the rotating cone assembly and that this could lead to component failure and loss of directional control of the helicopter.

The SB calls for inspecting the rotating cone assembly to determine its P/N. We make no requirement about how to determine the P/N. The compliance time for the SB is within 100 flight hours, while this AD requires compliance within 1 year or by the next annual inspection, whichever comes later.

We estimate that this AD affects 8 helicopters of U.S. Registry and that labor costs average $85 a work hour. We estimate that creating a component history card and revising the appropriate records takes 1 work-hour. No parts are needed for a total cost of $85 per helicopter and $680 for the U.S. fleet.

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 products 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):