DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2017-0874; Product Identifier 2015-SW-082-AD; Amendment
39-19282; AD 2018-10-07]
RIN 2120-AA64

Airworthiness Directives; Sikorsky Aircraft Corporation

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-76C helicopters. This
AD requires inspecting the engine collective position transducer (CPT).
This AD was prompted by reports of wear of the CPT that has resulted in
several One Engine Inoperative (OEI) incidents. The actions of this AD
are intended to detect and prevent an unsafe condition on these
products.

DATES: This AD is effective June 25, 2018.
The Director of the Federal Register approved the incorporation by
reference of certain documents listed in this AD as of June 25, 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. It is also available on the internet at http://www.
regulations.gov by searching for and locating Docket No. FAA-2017-
0874.

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-
0874; 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 AD, any incorporated-by-reference service information, the
economic evaluation, any comments received, and other information. The
street address for Docket Operations (phone: 800-647-5527) is 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: Nick Rediess, Aviation Safety
Engineer, Boston ACO Branch, Compliance & Airworthiness Division, 1200
District Avenue, Burlington, MA 01803; telephone (781) 238-7159; email
nicholas.rediess@faa.gov.

SUPPLEMENTARY INFORMATION:

Discussion

On September 14, 2017, at 82 FR 43195, 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 Sikorsky Model
S-76C helicopters with a Turbomeca, S.A., Arriel 2S1 or Arriel 2S2
engine with an engine CPT part number (P/N) 76900-01821-104 installed.
The NPRM was prompted by 20 reports of OEI incidents resulting from
wear of a CPT. One of these incidents resulted in a rejected takeoff to
an unprepared site.
The NPRM proposed to require initial and recurring inspections of
each CPT by measuring resistance, linearity resistance movement, and
differential voltage, and depending on the outcome of the inspections,
replacing the CPT. The proposed requirements were intended to detect
wear of a CPT prior to it causing an OEI condition and possible
emergency landing.

Comments

After our NPRM was published, we received comments from Sikorsky.

Request To Include an Additional Part to the AD

Sikorsky requested the AD also apply to engine CPT P/N 76900-01821-
105. In support of this request, Sikorsky stated that engine CPT P/N
76900-01821-105 is a new replacement for engine CPT P/N 76900-01821-
104, which does not differ substantially from engine CPT P/N 76900-
01821-104 and therefore should be subject to the periodic inspections.
We partially agree. While engine CPT P/N 76900-01821-105 may be
subject to the same unsafe condition because of design similarity,
adding this part would increase the scope of the AD. Therefore, we plan
to publish another NPRM for P/N 76900-01821-105 to give the public an
opportunity to comment on those requirements.

Request To Remove a Test Box From the AD

Sikorsky requested we remove Test Box P/N 76700-40009-042 and only
allow the use of Test Box P/N 76700-40009-043 to comply with the AD. In
support of this request, Sikorsky stated it considers Test Box P/N
76700-40009-042 obsolete because Test Box P/N 76700-40009-043 is easier
to use and provides less subjective results.
We disagree. The proposed AD provided procedures for both test
boxes for the repetitive inspections. While Test Box P/N 76700-40009-
043 may be more efficient, the use of Test Box P/N 76700-40009-042 also
addresses the unsafe condition. We do not find justification for
requiring operators who have Test Box P/N 76700-40009-042 to upgrade or
replace their test box. However, we have revised the initial inspection
requirements of the AD to allow the use of Test Box P/N 76700-40009-043
as an option. We have also revised the repetitive inspection procedures
to allow the use of updated testing procedures for Test Box P/N 76700-
40009-043, which had not been issued at the time we published the proposed
AD, as an option.
Lastly, Sikorsky requested we revise the unsafe condition to more
accurately describe that it would be a momentary OEI condition. In
support, Sikorsky stated that the unsafe condition statement in the
proposed AD could be misinterpreted as an in-flight shutdown or engine
failure. For this particular CPT failure, Sikorsky stated normal engine
operation is restored within approximately two seconds without the need
for any specific action by the pilot.
We agree and have made the requested change accordingly.

FAA's Determination

We have 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 the same type design and that
air safety and the public interest require adopting the AD requirements
as proposed with the changes described previously and minor editorial
changes. These changes are consistent with the intent of the proposals
in the NPRM and will not increase the economic burden on any operator
nor increase the scope of the AD.

Interim Action

We consider this AD to be an interim action. The design approval
holder is currently developing a modification that will address the
unsafe condition identified in this AD. Once this modification is
developed, approved, and available, we might consider additional
rulemaking.

Related Service Information Under 1 CFR Part 51

We reviewed Sikorsky S-76 Helicopter Alert Service Bulletin (ASB)
76-73-8, Revision A, dated December 4, 2015 (ASB 76-73-8A), which
specifies a one-time inspection of total resistance, linearity
resistant movement, excitation voltage, and differential voltage of the
CPTs using CPT Text Box P/N 76700-40009-042.
We reviewed Sikorsky Maintenance Manual, SA 4047-76C-2, Temporary
Revision No. 73-07, dated August 17, 2016 (TR 73-07), which specifies
procedures for removing, installing, and adjusting the CPTs, and
inspections of total resistance, linearity resistant movement,
excitation voltage, and differential voltage of the CPTs. TR 73-07 also
divides the procedures by CPT Test Box P/N by providing separate
procedures for test boxes modified by Sikorsky Special Service
Instructions (SSI) No. 76-96, dated August 19, 2016, which is not
incorporated by reference in this AD.
We also reviewed Sikorsky Maintenance Manual, SA 4047-76C-2,
Temporary Revision No. 73-08, dated September 20, 2017 (TR 73-08),
which updates the procedures in TR 73-07. TR 73-08 does not divide the
procedures by CPT Test Box P/N as it eliminates the procedures for CPT
Text Box P/N 76700-40009-042. TR 73-08 omits obsolete figures and it
provides inspection results as pass or fail.
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.

Other Related Service Information

We reviewed Sikorsky S-76 Helicopter ASB 76-73-8, Basic Issue,
dated August 21, 2015 (ASB 76-73-8). ASB 76-73-8 contains the same
procedures as ASB 76-73-8A; however, ASB 76-73-8A updates Sikorsky's
contact information for submitting a purchase order.
We also reviewed Sikorsky SA 4047-76C-2-1, Temporary Revision No.
5-181, dated August 21, 2015 (TR 5-181); Task 5-20-00 of Sikorsky
Airworthiness Limitations and Inspection Requirements, Publication No.
SA 4047-76C-2-1, Revision 24, dated December 15, 2015 (Task 5-20-00);
and Section 73-22-04 of Chapter 73 Engine Fuel and Control, of Sikorsky
Maintenance Manual, SA 4047-76C-2, Revision 31, dated December 15, 2015
(Section 73-22-04). TR 5-181 specifies adding CPT inspections
referenced in Section 73-22-04 to the 300-hour inspection checklist
contained in Task 5-20-00.
We reviewed Sikorksy Safety Advisory No. SSA-S76-11-0002, dated May
17, 2011. This service information provides precautionary instructions
to minimize hazardous situations that might result from an unreliable
CPT.
We also reviewed Sikorsky SSI No. 76-96, dated August 19, 2016,
which specifies procedures to modify CPT Test Box P/N 76700-40009-042
and re-identify it as P/N 76700-40009-043. This one-time modification
reduces the instructions to inspect the CPT and improves the inspection
accuracy.
We reviewed Sikorsky SSI No. 76-87, dated July 24, 2015, and SSI
No. 76-87A, Revision A, dated August 21, 2015. These SSIs specify a
one-time inspection of total resistance, linearity resistant movement,
excitation voltage, and differential voltage of the CPTs using CPT Text
Box P/N 76700-40009-042.

Differences Between This AD and the Service Information

Sikorsky ASB 76-73-8A, TR 73-07, and TR 73-08 specify using and
returning Sikorsky's CPT data sheet and any failed CPT to Sikorsky.
This AD does not.

Costs of Compliance

We estimate that this AD affects 90 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.
The inspections will take about 3.75 work-hours for an estimated
cost of $319 per helicopter and $28,710 for the U.S. fleet per
inspection cycle. Replacing a CPT will take about 6 work-hours and
parts will cost $3,072 for an estimated replacement cost of $3,582.

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):