DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2020-0483; Product Identifier 2016-SW-066-AD]
RIN 2120-AA64

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

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD)
for certain MD Helicopters Inc. (MDHI), Model 369A, 369D, 369E, 369FF,
369H, 369HE, 369HM, 369HS, 500N, and 600N helicopters. This proposed AD
would require tap inspecting each main rotor (MR) blade leading edge
abrasion strip and is prompted by reports of abrasion strips departing
the MR blade in-flight. The proposed actions are intended to prevent an
unsafe condition on these products.

DATES: The FAA must receive comments on this proposed AD by July 13, 2020.

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-2020-0483;
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, 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
Helicopter Technology Company, LLC, address 12902 South Broadway, Los
Angeles, CA 90061; telephone (310) 523-2750; email
gburdorf@helicoptertech.com; or at http://www.helicoptertech.com. 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: Payman Soltani, Aviation Safety
Engineer, Los Angeles ACO Branch, FAA, 3960 Paramount Blvd., Lakewood,
California 90712; telephone (562) 627-5313; email
payman.soltani@faa.gov.

SUPPLEMENTARY INFORMATION:

Comments Invited

The FAA invites you to participate in this rulemaking by submitting
written comments, data, or views. The FAA also invites comments
relating to the economic, environmental, energy, or federalism impacts
that might result from adopting the proposals in this document. The
most helpful comments reference a specific portion of the proposal,
explain the reason for any recommended change, and include supporting
data. To ensure the docket does not contain duplicate comments,
commenters should send only one copy of written comments, or if
comments are filed electronically, commenters should submit only one
time.

The FAA will file in the docket all comments received, as well as a
report summarizing each substantive public contact with FAA personnel
concerning this proposed rulemaking. Before acting on this proposal,
the FAA will consider all comments received on or before the closing
date for comments. The FAA will consider comments filed after the
comment period has closed if it is possible to do so without incurring
expense or delay. The FAA may change this proposal in light of the
comments received.

Discussion

The FAA proposes to adopt a new AD for MDHI Model 369A, 369D, 369E,
369FF, 369H, 369HE, 369HM, 369HS, 500N, and 600N helicopters with an MR
blade part number (P/N) 500P2100-105, P/N 500P2100-305, P/N 500P2300-
505, P/N 369D21120-505, P/N 369D21121-505, or P/N 369D21123-505, with a
1.25-inch chord length nickel abrasion strip (abrasion strip)
manufactured or installed by Helicopter Technology Company (HTC) or
where the manufacturer of the abrasion strip is unknown. This proposed
AD would require tap inspecting the abrasion strip within 10 hours
time-in-service (TIS) and thereafter before the first flight of each
day until the abrasion strip has accumulated 700 hours TIS since
installation.

This proposed AD is prompted by reports that leading edge abrasion
strips manufactured by HTC are departing the MR blades during flight.
An investigation determined that the abrasion strips were manufactured
from electroformed nickel, have a chord length of 1.25 inch, and are
delaminating from the MR blade before departing from the helicopter.
HTC has determined that a repetitive tap inspection of the abrasion
strips should be performed on all blades with abrasion strips that have
less than 700 hours TIS to detect any voids, including blistering,
bubbling, or lifting of the abrasion strip. Identical looking
electroformed nickel abrasion strips with a chord length of 1.25 inch
manufactured by other repair stations have not departed in flight and
therefore are not the subject of this proposed AD. If the manufacturer
of the installed abrasion strip is unknown, this proposed AD would
apply to the strip.

FAA's Determination

The FAA is proposing this AD because the agency evaluated all known
relevant information and determined that an 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

The FAA reviewed HTC Mandatory Service Bulletin Notice No. 2100-
8R4, dated June 1, 2017, which specifies a daily tap inspection of the
MR blade abrasion strip to detect voids. If there are any voids, the SB
specifies repairing or replacing the MR blade, depending on the size,
quantity, and location of any damage.

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.

Proposed AD Requirements

This proposed AD would require, within 10 hours TIS and thereafter
before the first flight of each day until the abrasion strip reaches
700 hours TIS, tap inspecting the leading edge abrasion strip for a
void. If there is a void within 0.5 inch (12.7 mm) of the edge of the
abrasion strip, the proposed AD would require replacing the blade with
an airworthy blade before further flight. If there is a void that is
not within 0.5 inch (12.7 mm) from the edge of the abrasion strip and
is larger than 0.5 square inch (322.6 square mm) or if there is more
than one void of any size, the proposed AD would require replacing the
blade with an airworthy blade before further flight.

Costs of Compliance

The FAA estimates that this proposed AD would affect 50 helicopters
of U.S. Registry.

The FAA estimates that operators may incur the following costs in
order to comply with this AD. At an average labor rate of $85 per hour,
tap-testing the MR blades will require about 0.25 work-hour, for a cost
per helicopter of $22 per inspection cycle.

If required, replacing an MR blade would require 1 work-hour, and
required parts would cost up to $24,130, for a cost per helicopter of
$24,215.

According to HTC's 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 HTC. Accordingly, the FAA has included all costs in our
cost estimate.

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 this proposed regulation:

1. Is not a "significant regulatory action" under Executive Order
12866;

2. Will not affect intrastate aviation in Alaska to the extent that
it justifies making a regulatory distinction; 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.

Sec. 39.13 [Amended]

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