AD 2016-01-19

We are adopting a new airworthiness directive (AD) for MD Helicopters Inc. (MDHI) Model 500N and 600N helicopters with certain rotating cone assemblies installed. This AD requires establishing a life limit of 10,000 hours time-in-service (TIS) on these rotating cone assemblies. This AD was prompted by the determination that MDHI created rotating cone assemblies with new dash numbers but incorrectly failed to identify them as life-limited parts. The actions are 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.

Final rule.

Adoption of the Amendment

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

PART 39--AIRWORTHINESS DIRECTIVES

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

Authority: 49 U.S.C. 106(g), 40113, 44701.

Sec. 39.13 [Amended]

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

2016-01-19 MD Helicopters Inc.: Amendment 39-18379; Docket No. FAA- 2015-1998; Directorate Identifier 2014-SW-035-AD.

(a) Applicability

This AD applies to MD Helicopters Inc. (MDHI) Model 500N 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, certificated in any category.

(b) Unsafe Condition

This AD defines the unsafe condition as a rotating cone assembly remaining in service beyond its fatigue life. This condition could result infailure of the rotating cone assembly and loss of control of the helicopter.

(c) Effective Date

This AD becomes effective February 25, 2016.

(d) 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.

(e) Required Actions

(1) Within 1 year or at the next annual inspection, whichever comes later:
(i) Create a component history card or equivalent record for each rotating cone assembly, P/N 500N3740-81 and P/N 500N3740-71, and record a life limit of 10,000 hours time-in-service (TIS).
(ii) Revise the Airworthiness Limitations Section of the applicable maintenance manual or Instructions for Continued Airworthiness by establishing a new retirement life of 10,000 hours TIS for each rotating cone assembly, P/N 500N3740-81 and P/N 500N3740-71, by making pen-and-ink changes or by inserting a copy of this AD into the Airworthiness Limitations Section of the maintenance manual or the Instructions for Continued Airworthiness.
(iii) Remove from service any rotating cone assembly, P/N 500N3740-81 and P/N 500N3740-71, that has 10,000 or more hours TIS.
(2) Do not install a rotating cone assembly, P/N 500N3740-81 or P/N 500N3740-71, on any helicopter unless you have complied with the requirements of this AD.

(f) Alternative Methods of Compliance (AMOCs)

(1) The Manager, Los Angeles Aircraft Certification Office, FAA, may approve AMOCs for this AD. Send your proposal to: Galib Abumeri, Aerospace Engineer, Los Angeles Aircraft Certification Office, Transport Airplane Directorate, FAA, 3960 Paramount Blvd., Lakewood, California 90712, telephone 562-627-5324; email 9-ANM-LAACO-AMOC-REQUESTS@faa.gov.
(2) For operations conducted under a 14 CFR part 119 operating certificate or under 14 CFR part 91, subpart K, we suggest 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.

(g) Additional Information

MD Helicopters Inc. Service Bulletin SB500N-046/SB600N-054, dated July 9, 2012, which is not incorporated by reference, contains additional information about the subject of this AD. For service information identified in this AD, 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 this service information at the FAA, Office of the Regional Counsel, Southwest Region, 10101 Hillwood Pkwy, Room 6N-321, Fort Worth, TX 76177.

(h) Subject

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

Discussion

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.

Comments

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).

FAA's Determination

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.

Related Service Information

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.

Differences Between This AD and the Service Information

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.

Costs of Compliance

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.

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

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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.

Regulatory Findings

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.List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.