DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2018-0991; Product Identifier 2017-SW-050-AD; Amendment
39-19586; AD 2019-05-04]
RIN 2120-AA64

Airworthiness Directives; MD Helicopters, Inc. (MDHI), Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: We are adopting a new airworthiness directive (AD) for MDHI
Model 369A, 369D, 369E, 369FF, 369H, 369HE, 369HM, 369HS, 500N, and
600N helicopters. This AD requires inspecting each main rotor blade
(MRB) for a crack. This AD was prompted by reports of cracked MRBs. The
actions of this AD are intended to address an unsafe condition on these
helicopters.

DATES: This AD is effective April 17, 2019.

ADDRESSES: For Helicopter Technology Company, LLC, service information
identified in this final rule, contact Helicopter Technology Company,
LLC, 12902 South Broadway, Los Angeles, CA 90061; telephone (310) 523-
2750; or at www.helicoptertech.com. For MD Helicopters 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.

Examining the AD Docket

You may examine the AD docket on the internet at http://www.regulations.gov
by searching for and locating Docket No. FAA-2018-
0991; 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 AD, the economic evaluation, any comments received, and other
information. The street address for Docket Operations (phone: 800-647-
5527) is U.S. Department of Transportation, Docket Operations, M-30,
West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE,
Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: Galib Abumeri, Aviation Safety
Engineer, Los Angeles ACO Branch, Compliance & Airworthiness Division,
FAA, 3960 Paramount Blvd., Lakewood, CA 90712; telephone (562) 627-
5374; email galib.abumeri@faa.gov.

SUPPLEMENTARY INFORMATION:

Discussion

On November 26, 2018, at 83 FR 60376, 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
369A, 369D, 369E, 369FF, 369H, 369HE, 369HM, 369HS, 500N, and 600N
helicopters with a Helicopter Technology Company, LLC (HTC), MRB part
number 369A1100, 369D21100, 369D21102, 369D21120, 369D21121, 369D21123,
500P2100, or 500P2300 installed. The NPRM was prompted by reports of
two operators finding cracks on an HTC-manufactured MRB and proposed to
require repetitively inspecting each MRB trim tab for a crack. The
proposed requirements were intended to prevent failure of an MRB and
subsequent loss of control of the helicopter.
In the ``Costs of Compliance'' section, the NPRM stated an
incorrect number of U.S.-registered helicopters affected by this AD and
subsequently, an incorrect estimated cost of the inspection for the
U.S. fleet. We have corrected the cost information in this Final rule.

Comments

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

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

We reviewed HTC Mandatory Service Bulletin Notice No. 2100-9, dated
May 25, 2017 (SB 2100-9), which contains
procedures for inspecting each MRB for a crack in an area adjacent to
the inboard edge of the MRB trim tab.
We also reviewed MD Helicopters Service Bulletin No. SB369D-221,
SB369E-119, SB369F-106, SB369H-257, SB500N-057, and SB600N-069, each
dated April 2, 2018. This service information specifies inspecting the
MRBs for cracks near the trim tab by following the instructions in SB
2100-9.

Differences Between This AD and the Service Information

The service information specifies procedures for inspecting each
MRB for nicks, gouges, and scratches. This AD does not, as the unsafe
condition concerns a crack in the MRB.

Costs of Compliance

We estimate that this AD affects 730 helicopters of U.S. Registry.
We estimate that operators may incur the following costs in order to
comply with this AD. Labor costs are estimated at $85 per work-hour.
Inspecting one MRB requires about 0.1 work-hour, for an estimated
cost per helicopter of $43 for the 705 MDHI Model 369-series and 500N
helicopters (5 MRBs), $51 for the 25 MDHI Model 600N helicopters (6
MRBs), and a total estimated cost of $31,590 for the U.S. fleet per
inspection cycle.
If required, replacing one MRB requires about 3 work-hours and
parts cost about $13,000 for a total estimated cost of $13,255 per MRB.

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.
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, 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.

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

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]

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