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

[Federal Register Volume 85, Number 185 (Wednesday, September 23, 2020)]
[Rules and Regulations]
[Pages 59663-59665]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-20930]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2020-0483; Product Identifier 2016-SW-066-AD; Amendment 
39-21241; AD 2020-18-20]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: The FAA is adopting 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 AD was prompted 
by reports of abrasion strips departing the main rotor (MR) blade in-
flight. This AD requires tap inspecting each MR blade leading edge 
abrasion strip. The FAA is issuing this AD to address the unsafe 
condition on these products.

DATES: This AD is effective October 28, 2020.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of October 28, 
2020.

ADDRESSES: For service information identified in this final rule, 
contact Helicopter Technology Company, LLC, address 12902 South 
Broadway, Los Angeles, CA 90061; telephone (310) 523-2750; email 
[email protected]; or at http://www.helicoptertech.com. You 
may view this service information at the FAA, Office of the Regional 
Counsel, Southwest Region, 10101 Hillwood Pkwy, Room 6N-321, Fort 
Worth, TX 76177. For information on the availability of this material 
at the FAA, call (817) 222-5110. It is also available on the internet 
at https://www.regulations.gov by searching for and locating Docket No. 
FAA-2020-0483.

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 final rule, any comments received, and other information. The 
address for Docket Operations is Docket Operations, 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: Payman Soltani, Aviation Safety 
Engineer, Los Angeles ACO Branch, FAA, 3960 Paramount Blvd., Lakewood, 
California 90712; telephone (562) 627-5313; email 
[email protected].

SUPPLEMENTARY INFORMATION:

Discussion

    The FAA issued a notice of proposed rulemaking (NPRM) 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 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, LLC 
(HTC), or

[[Page 59664]]

where the manufacturer of the abrasion strip is unknown, except if the 
abrasion strip has accumulated 700 or more hours time-in-service (TIS). 
The NPRM published in the Federal Register on May 14, 2020 (85 FR 
28895).
    The NPRM was prompted by reports of leading edge abrasion strips 
manufactured by HTC 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 were not proposed as the subject of this AD.
    To address this unsafe condition, the NPRM proposed to require tap 
inspecting the abrasion strip within 10 hours TIS and thereafter before 
the first flight of each day until the abrasion strip has accumulated 
700 or more hours TIS since installation.

Comments

    The FAA gave the public the opportunity to participate in 
developing this final rule. The following presents the comments 
received on the NPRM and the FAA's response to each comment.

Supportive Comment

    The FAA received one comment in support of the NPRM.

Requests

    Request: HTC stated that the NPRM proposed to mandate its service 
bulletin that was issued June 1, 2017, and that there has not been a 
documented case of an abrasion strip departure related to this issue in 
4 years. HTC further stated that the majority of affected operators 
have either modified the abrasion strip or accumulated more than 700 
hours TIS, such that the proposed AD would no longer apply. Although 
HTC did not request any changes to the NPRM, the FAA infers that this 
commenter would like the FAA to withdraw the proposed AD.
    FAA's Response: The FAA partially agrees. The FAA has not received 
any reports of an abrasion strip departure related to this issue since 
issuance of the HTC service bulletin. In addition, about a third of the 
abrasion strips have been modified and others have accumulated more 
than 700 hours TIS, and therefore would not be affected by this AD. 
However, because some affected abrasion strips are still in service or 
may be stored as spare parts, the unsafe condition exists and 
corrective action is necessary. The FAA has made no changes based on 
these comments.
    Request: Wilson Construction requested that the FAA change the NPRM 
to allow pilots to perform the tap test following proper training, to 
avoid difficulties complying with the AD while away from base of 
operations or during cross country flights. The commenter stated that 
this would be consistent with AD 88-17-09 R1 (Amendment 39-6400; 54 FR 
48583, November 24, 1989) (``AD 88-17-09 R1''), which allows a pilot to 
perform a pre-flight check, and that the test itself is simple to 
perform.
    FAA's Response: The FAA disagrees. AD 88-17-09 R1 allows the pilot 
to perform a check of the tail boom extension for security. This check 
is an exception to the FAA's standard maintenance regulations and is 
allowed in AD 88-17-09 R1 because it is a visual check that can be 
performed equally well by a pilot or a mechanic and does not require 
training or the use of tools. Since the tap inspection proposed in the 
NPRM would require both training and the use of a tool, allowing a 
pilot to perform it is not acceptable. The FAA made no changes in this 
final rule based on this comment.
    Request: Wilson Construction stated the inspection criteria in the 
proposed AD are already specified by the manufacturer of the MR blades 
(HTC) and by MDHI. The commenter stated if owners/operators would 
follow the manufacturer's instructions, then an AD would not be 
necessary.
    FAA's Response: The FAA agrees. Not all operators are required to 
incorporate a manufacturer's maintenance instructions into the 
operator's maintenance program. Where the FAA has determined that a 
manufacturer's maintenance instructions are necessary to correct an 
unsafe condition, the FAA must issue an AD to mandate those 
instructions. The FAA made no changes in this final rule based on this 
comment.

FAA's Determination

    The FAA has reviewed the relevant information, considered the 
comments received, 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 with minor editorial changes. These 
minor changes are consistent with the proposals in the NPRM and will 
not increase the economic burden on any operator nor increase the scope 
of the AD.

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, this 
service information 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.

Costs of Compliance

    The FAA estimates that this AD affects 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 
requires about 0.25 work-hour, for a cost per helicopter of $22 per 
inspection cycle. If required, replacing an MR blade requires about 1 
work-hour and required parts 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 
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 this 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

[[Page 59665]]

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) Will not affect intrastate aviation in Alaska, 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.

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):

2020-18-20 MD Helicopters Inc. (MDHI): Amendment 39-21241; Docket 
No. FAA-2020-0483; Product Identifier 2016-SW-066-AD.

(a) Applicability

    This AD applies to MD Helicopters Inc. (MDHI) Model 369A, 369D, 
369E, 369FF, 369H, 369HE, 369HM, 369HS, 500N, and 600N helicopters, 
certificated in any category, with a main rotor (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, LLC 
(HTC), or where the manufacturer of the abrasion strip is unknown. 
This AD does not apply if the abrasion strip has accumulated 700 or 
more hours time-in-service (TIS).

(b) Unsafe Condition

    This AD defines the unsafe condition as failure of the bond 
between the leading edge abrasion strip and an MR blade. This 
condition could result in the abrasion strip departing the MR blade 
in-flight, subsequent imbalance of the rotor system, and loss of 
control of the helicopter.

(c) Effective Date

    This AD becomes effective October 28, 2020.

(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

    Within 10 hours TIS and thereafter before the first flight of 
each day, tap inspect each MR blade leading edge abrasion strip for 
a void in accordance with Part 1--Inspection, paragraphs 2 through 
4, of HTC Mandatory Service Bulletin Notice No. 2100-8R4, dated June 
1, 2017.
    (1) If there is a void within 0.5 inch (12.7 mm) of the edge of 
the abrasion strip, before further flight, replace the MR blade.
    (2) If there is a void larger than 0.5 square inch (322.6 square 
mm) or if there is more than one void of any size, before further 
flight, replace the MR blade.

(f) Alternative Methods of Compliance (AMOC)

    (1) The Manager, Los Angeles ACO Branch, FAA, may approve AMOCs 
for this AD. Send your proposal to: Payman Soltani, Aviation Safety 
Engineer, Los Angeles ACO Branch, FAA, 3960 Paramount Blvd., 
Lakewood, California 90712; telephone (562) 627-5313; email [email protected].
    (2) For operations conducted under a 14 CFR part 119 operating 
certificate or under 14 CFR part 91, subpart K, the FAA suggests 
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) Subject

    Joint Aircraft Service Component (JASC) Code: 6210, Main Rotor 
Blade.

(h) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference (IBR) of the service information listed 
in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this service information as applicable to do 
the actions required by this AD, unless the AD specifies otherwise.
    (i) Helicopter Technology Company, LLC, Mandatory Service 
Bulletin Notice No. 2100-8R4, dated June 1, 2017.
    (ii) [Reserved]
    (3) For service information identified in this AD, contact 
Helicopter Technology Company, LLC, address 12902 South Broadway, 
Los Angeles, CA 90061; telephone (310) 523-2750; email 
[email protected]; or at http://www.helicoptertech.com.
    (4) You may view this service information at the FAA, Office of 
the Regional Counsel, Southwest Region, 10101 Hillwood Pkwy, Room 6N 
321, Fort Worth, TX 76177. For information on the availability of 
this material at the FAA, call (817) 222-5110.
    (5) You may view this service information that is incorporated 
by reference at the National Archives and Records Administration 
(NARA). For information on the availability of this material at 
NARA, email [email protected], or go to: https://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued on August 31, 2020.
Gaetano A. Sciortino,
Deputy Director for Strategic Initiatives, Compliance & Airworthiness 
Division, Aircraft Certification Service.
[FR Doc. 2020-20930 Filed 9-22-20; 8:45 am]
BILLING CODE 4910-13-P

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