DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2020-0064; Project Identifier 2019-SW-096-AD; Amendment
39-21132; AD 2020-11-07]
RIN 2120-AA64

Airworthiness Directives; MD Helicopter Inc., 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 MD
Helicopters Inc., (MDHI) Model 369D, 369E, 369FF, 369H, 369HE, 369HM,
369HS, 500N, and 600N helicopters. This AD was prompted by a report of
non-conforming main rotor (M/R) hub lead-lag bolts (bolts). This AD
requires removing certain bolts from service. The FAA is issuing this
AD to address the unsafe condition on these products.

DATES: This AD is effective June 30, 2020.
The Director of the Federal Register approved the incorporation by
reference of certain publications listed in this AD as of June 30,
2020.

ADDRESSES: 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 https://www.mdhelicopters.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
http://www.regulations.gov by searching for and locating Docket No.
FAA-2020-0064.

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-
0064; 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, Aerospace Engineer,
Los Angeles ACO Branch, FAA, 3960 Paramount Blvd., Lakewood, California
90712; telephone 562-627-5313; email payman.soltani@faa.gov.

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 369D, 369E,
369FF, 369H, 369HE, 369HM, 369HS, 500N, and 600N helicopters, with
certain serial-numbered bolts part number (P/N) 369D21220 installed.
The NPRM published in the Federal Register on February 7, 2020 (85 FR
7256). The NPRM was prompted by a report of non-conforming bolts.
Certain serial-numbered bolts had an unauthorized repair of their
cadmium plating performed between April 2004 and October 2018. Analysis
has shown that these bolts have a lower fatigue life compared to bolts
used during manufacturing batch testing. The NPRM proposed to require
removing the affected bolts from service.
This condition, if not addressed, could result in loss of an M/R
blade and subsequent loss of control of the helicopter. The FAA is
issuing this AD to address the unsafe condition on these products.

Comments

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

Request

The commenter stated that the labor hours provided in the NPRM to
replace a bolt are underestimated because bolt replacement cannot be
performed while the M/R is installed on the rotorcraft. The cost
estimation should include removal of the M/R blades, M/R driveshaft,
and M/R head.
The FAA agrees and has updated the Costs of Compliance for this AD.

Conclusion

The FAA reviewed the relevant data, considered the comments
received, and determined that air safety and the public interest
require adopting this final rule as proposed except for adjusting the
labor hours to replace a bolt. The FAA has determined that this change:
Is consistent with the intent that was proposed in the
NPRM for addressing the unsafe condition; and
Does not add any significant burden upon the public than
was already proposed in the NPRM.

Related Service Information Under 1 CFR Part 51

The FAA reviewed MD Helicopters Service Bulletin No. SB369D-223 for
Model 369D helicopters, No. SB369E-122 for Model 369E helicopters, No.
SB369F-110 for Model 369FF helicopters, No. SB369H-259 for Model 369H,
369HE, 369HS, and 369HM helicopters, No. SB500N-060 for Model 500N
helicopters, and No. SB600N-073 for Model 600N helicopters, each dated
April 19, 2019. These service bulletins are co-published as one
document. This service information specifies determining the serial
number of bolt P/N 369D21220, and if certain serial-numbered bolts are
installed on a helicopter, contacting MDHI to schedule replacement of
each affected bolt and reporting information. This service information
also specifies returning removed parts to MDHI along with a completed
Service Operation Report.
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.

Differences Between This AD and the Service Information

The service information specifies reporting information and
returning removed parts to MDHI, whereas this AD does not require
either of those actions. The service information specifies replacing
the affected bolts within 12 months, whereas this AD requires replacing
the affected bolts within three months of the effective date of this
AD.

Costs of Compliance

The FAA estimates that this AD affects 767 helicopters of U.S.
registry. Labor rates are estimated at $85 per work-hour. Based on
these numbers, the FAA estimates the following costs to comply with
this AD.
Replacing a bolt takes about 1.75 work-hours and parts cost about
$178 for an estimated cost of $327 per bolt.
According to MDHI, 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 for affected
individuals. As a result, 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 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

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):