DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2017-0491; Product Identifier 2016-SW-020-AD; Amendment
39-19031; AD 2017-19-01]
RIN 2120-AA64

Airworthiness Directives; Sikorsky Aircraft Corporation
Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: We are adopting a new airworthiness directive (AD) for
Sikorsky Aircraft Corporation (Sikorsky) Model S-76A, S-76B, S-76C, and
S-76D helicopters. This AD requires inspecting the main rotor (M/R)
servo pushrod (pushrod) assembly and applying slippage marks. This AD
was prompted by an accident of a Sikorsky Model S-76C helicopter caused
by a failed pushrod assembly. The actions of this AD are intended to
prevent an unsafe condition on these products.

DATES: This AD is effective January 2, 2018.

ADDRESSES: For service information identified in this final rule,
contact Sikorsky Aircraft Corporation, Customer Service Engineering,
124 Quarry Road, Trumbull, CT 06611; telephone 1-800-
Winged-S or 203-416-4299; email: wcs_cust_service_eng.gr-sik@lmco.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-2017-
0491; or in person at the Docket Operations Office 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 the Docket Operations Office
(phone: 800-647-5527) is U.S. Department of Transportation, Docket
Operations Office, M-30, West Building Ground Floor, Room W12-140, 1200
New Jersey Avenue SE., Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: Blaine Williams, Aerospace Engineer,
Boston ACO Branch, Compliance and Airworthiness Division, 1200 District
Avenue, Burlington, Massachusetts 01803; telephone (781) 238-7161;
email blaine.williams@faa.gov.

SUPPLEMENTARY INFORMATION:

Discussion

On June 5, 2017, at 82 FR 25748, 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 Model S-76A, S-76B, S-76C,
and S-76D helicopters, serial numbers up to and including 761075, with
an M/R pushrod assembly part number (P/N) 76400-00034-059, 76400-00014-
074, 76400-00014-076, or 76400-00014-077 installed. The NPRM proposed
to require inspecting each pushrod assembly and applying two slippage
marks across each control rod and jamnut. Depending on the outcome of
the inspection, the NPRM proposed to require replacing the pushrod
assembly or inspecting the jamnut. Depending on the outcome of
inspecting the jamnut, the NPRM proposed to require replacing the
pushrod assembly or applying 140 inch-pounds of torque to the jamnut.
The proposed requirements were intended to detect a loose jamnut and
prevent failure of the pushrod assembly, loss of M/R flight control,
and subsequent loss of control of the helicopter.
Since the NPRM was issued, the FAA's Aircraft Certification Service
has changed its organizational structure. The new structure replaces
product directorates with functional divisions. We have revised some of
the office titles and nomenclature throughout this Final rule to
reflect the new organizational changes. Additional information about
the new structure can be found in the Notice published on July 25, 2017
(82 FR 34564).

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 Sikorksy S-76 Helicopter Alert Service Bulletin 76-67-
58, Basic Issue, dated November 19, 2015 (ASB), which specifies a one-
time inspection of the M/R forward, aft, and lateral pushrod assemblies
and jamnuts for proper installation, condition, and security. If a
pushrod or jamnut does not meet criteria specified in the inspections,
the ASB specifies replacing the assembly. The ASB also specifies
applying torque to each jamnut and applying two slippage marks across
each control rod and jamnut.

Differences Between This AD and the Service Information

The Sikorsky ASB specifies returning any removed M/R pushrod
assembly to Sikorsky. This AD does not require returning any parts to
Sikorsky.

Costs of Compliance

We estimate that this AD affects 198 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 the M/R pushrod assemblies takes about 2.2 work-hours for an
estimated cost of $187 per helicopter and $37,026 for the U.S. fleet.
Replacing an M/R pushrod assembly takes about 2 work-hours for a labor
cost of $170. Parts to replace M/R pushrod assembly P/N 76400-00034-059
cost about $2,411 for a total estimated replacement cost of $2,581.
Parts to replace M/R pushrod assembly P/N 76400-00014-074 cost about
$2,224 for a total estimated replacement cost of $2,394. Parts to
replace M/R pushrod assembly P/N 76400-00014-076 cost about $2,488 for
a total estimated replacement cost of $2,658. Parts to replace M/R
pushrod assembly P/N 76400-00014-077 cost about $2,414 for a total
estimated replacement cost of $2,584. It takes a minimal amount of time
to apply the slippage marks for a negligible cost.

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 to the extent
that it justifies making a regulatory distinction; 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):