DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-0610; Project Identifier AD-2021-00126-R;
Amendment 39-21868; AD 2021-26-09]
RIN 2120-AA64

Airworthiness Directives; Brantly Helicopters Industries U.S.A.
Co., Ltd., and Brantly International, 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
certain Brantly Helicopters Industries U.S.A. Co., Ltd., Model 305
helicopters and Brantly International, Inc., Model B-2, B-2A, and B-2B
helicopters. This AD was prompted by a report of a crack in the tail
rotor (T/R) hub. This AD requires repetitive inspections of the T/R hub
and depending on the results, removing the T/R hub from service. The
FAA is issuing this AD to address the unsafe condition on these
products.

DATES: This AD is effective January 19, 2022.

ADDRESSES: For service information identified in this final rule,
contact Brantly International, Inc., Bill Ross, 621 S Royal Lane, Suite
100, Coppell, TX 75019, United States; phone: (972) 829-4699; email:
bross@superiorairparts.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.

Examining the AD Docket

You may examine the AD docket at https://www.regulations.gov by
searching for and locating Docket No. FAA-2021-0610; 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 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: Marc Belhumeur, Senior Project
Engineer, Certification Section, Fort Worth ACO Branch, Compliance &
Airworthiness Division, FAA, 10101 Hillwood Pkwy., Fort Worth, TX
76177; telephone (817) 222-5177; email 9-ASW-FWACO@faa.gov.

SUPPLEMENTARY INFORMATION:

Background

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14
CFR part 39 by adding an AD that would apply to certain Brantly
Helicopters Industries U.S.A. Co., Ltd., Model 305 helicopters and
Brantly International, Inc., Model B-2, B-2A, and B-2B helicopters. The
NPRM published in the Federal Register on July 30, 2021 (86 FR 40967).
The NPRM was prompted by a report of a crack in T/R hub part number (P/
N) 2951. In the NPRM, the FAA proposed to require repetitively
cleaning, and using a 10X or higher power magnifying glass, inspecting
the areas where each T/R blade attaching arm extends from the T/R hub
for a crack, corrosion, and pitting, and depending on the results,
removing the T/R hub from service. This NPRM also proposed to require
repetitively cleaning and dye penetrant inspecting the radius at the
shoulder of each T/R hub spindle for a crack and pitting, and depending
on the results, removing the T/R hub from service.
This condition, if not addressed, could result in loss of T/R
control and subsequent loss of control of the helicopter. The FAA is
issuing this AD to address the unsafe condition on these products.

Discussion of Final Airworthiness Directive

Comments

The FAA received comments from one individual. The commenter
supports the proposal but recommended the FAA acquire sufficient data
regarding the unsafe condition and investigate to determine if this
unsafe condition exists on the T/R hub of other helicopters. The
following presents the comments received on the NPRM and the FAA's
response to each comment.

Request Regarding the FAA's Justification of the Unsafe Condition

The individual recommended that prior to implementing the proposed
rule, the FAA ensure adequate data has been acquired and proceed if the
frequency of incident is proven to be material.
Prior to issuing the NPRM, the FAA reviewed the report and
associated data for a crack in the T/R hub. In accordance with FAA
Order 8110.107A Monitor Safety/Analyze Data, the FAA has determined
that an unsafe condition exists that supports AD action.

Request Pertaining to Other Model Helicopters

The individual stated that the FAA should investigate whether
issues exist in the T/R hub of other model helicopters.
No data has been provided to substantiate the individual's comment;
however, available data for this unsafe condition is limited to T/R hub
P/N 161-1 and 2951, which are only approved for installation on Brantly
Helicopters Industries U.S.A. Co., Ltd., Model 305 helicopters and
Brantly International, Inc., Model B-2, B-2A, and B-2B helicopters.

Conclusion

The FAA reviewed the relevant data, considered any comments
received, and determined that air safety requires adopting this AD as
proposed. Accordingly, the FAA is issuing this AD to address the unsafe
condition on these products. Except for a minor editorial change to
paragraph (e) of this AD, this AD is adopted as proposed in the NPRM.
This change will not increase the economic burden on any operator.

Related Service Information

The FAA reviewed Brantly Helicopter Service Letter No. 102, dated
July 11, 1974 (SL 102). SL 102 specifies repetitively cleaning and
inspecting the areas where each T/R blade attaching arm extends from
the T/R hub for a crack. SL 102 also specifies repetitively cleaning
and dye penetrant inspecting the radius at the shoulder of each T/R hub
spindle for a crack. If there is a crack, SL 102 specifies replacing
the part and reporting any cracks to Brantly Operators, Inc.

Differences Between This AD and the Service Information

SL 102 applies to all Brantly helicopters, whereas this AD applies
to helicopters with T/R hub P/N 2591 or 161-1 installed. This AD
requires using a 10X or higher power magnifying glass when inspecting
the area where the T/R blade attaching arm extends from the T/R hub for
a crack, corrosion, and pitting, whereas SL 102 does not specify using
a magnifying glass and only specifies inspecting for a crack in that
area. This AD requires dye penetrant inspecting the radius at the
shoulder of each T/R spindle for a crack and pitting, whereas SL 102
only specifies dye penetrant inspecting for a crack in those areas.
SL102 specifies reporting any cracks to Brantly Operators, Inc.,
whereas this AD does not require reporting any information.

Costs of Compliance

The FAA estimates that this AD affects 57 helicopters of U.S.
Registry. Labor rates are estimated at $85 per work-hour. Based on
these numbers, the FAA estimates that operators may incur the following
costs in order to comply with this AD.
Cleaning and inspecting the T/R hub with a magnifying glass takes
about 1 work-hour for an estimated cost of $85 per helicopter and
$4,845 for the U.S. fleet, per inspection cycle. Cleaning and dye
penetrant inspecting the T/R hub takes about 2 work-hours for an
estimated cost of $170 per helicopter and $9,690 for the U.S. fleet,
per inspection cycle. If required, replacing a T/R hub takes about 0.5
work-hour and parts cost about $500 for an estimated cost of $543 per
replacement.

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.

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: