DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2017-0896; Product Identifier 2017-SW-034-AD]
RIN 2120-AA64

Airworthiness Directives; Sikorsky Aircraft Corporation
Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to supersede airworthiness directive (AD) 2017-07-
02 for Sikorsky Aircraft Corporation (Sikorsky) Model 269D and Model
269D Configuration A helicopters. AD 2017-07-02 currently requires
reducing the life limit of and inspecting certain drive shafts. This
proposed AD would retain the requirements of AD 2017-07-02 and propose
repeating the inspections. The actions of this proposed AD are intended
to detect and prevent an unsafe condition on these products.

DATES: We must receive comments on this proposed AD by November 21,
2017.

ADDRESSES: You may send comments by any of the following methods:
Federal eRulemaking Docket: Go to http://www.regulations.gov. Follow the online
instructions for sending your comments electronically.
Fax: 202-493-2251.
Mail: Send comments to the U.S. Department of
Transportation, Docket Operations, M-30, West Building Ground Floor,
Room W12-140, 1200 New Jersey Avenue SE., Washington, DC 20590-0001.
Hand Delivery: Deliver to the ``Mail'' address between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.

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-
0896; 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 proposed AD, the economic evaluation, any comments
received and other information. The street address for the Docket
Operations Office (telephone 800-647-5527) is in the ADDRESSES section.
Comments will be available in the AD docket shortly after receipt.
For service information identified in this proposed 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 service
information at the FAA, Office of the Regional Counsel, Southwest
Region, 10101 Hillwood Pkwy., Room 6N-321, Fort Worth, TX 76177.

FOR FURTHER INFORMATION CONTACT: Michael Schwetz, Aviation Safety
Engineer, Boston ACO Branch, Compliance and Airworthiness Division,
FAA, 1200 District Avenue, Burlington, Massachusetts 01803; telephone
(781) 238-7761; email michael.schwetz@faa.gov.

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to participate in this rulemaking by submitting
written comments, data, or views. We also invite comments relating to
the economic, environmental, energy, or federalism impacts that might
result from adopting the proposals in this document. The most helpful
comments reference a specific portion of the proposal, explain the
reason for any recommended change, and include supporting data. To
ensure the docket does not contain duplicate comments, commenters
should send only one copy of written comments, or if comments are filed
electronically, commenters should submit only one time.
We will file in the docket all comments that we receive, as well as
a report summarizing each substantive public contact with FAA personnel
concerning this proposed rulemaking. Before acting on this proposal, we
will consider all comments we receive on or before the closing date for
comments. We will consider comments filed after the comment period has
closed if it is possible to do so without incurring expense or delay.
We may change this proposal in light of the comments we receive.

Discussion

On March 20, 2017, we issued a Final rule; request for comments to
add AD 2017-07-02, Amendment 39-18840 (82 FR 15120, March 27, 2017) for
Sikorsky Model 269D and Model 269D Configuration A helicopters with a
KAflex engine side drive shaft part number (P/N) SKCP2738-7 and KAflex
pulley side drive shaft P/N SKCP2738-5 installed. AD 2017-07-02
requires reducing the life limit of the drive shafts and performing
several inspections of the drive shafts within 25 hours time-in-service
(TIS). AD 2017-07-02 also specifies replacing the drive shaft
assemblies as an optional terminating action for the requirements of
the AD. AD 2017-07-02 was prompted by four incidents involving failure
of the engine side drive shaft. The actions required by AD 2017-07-02
are intended to prevent failure of the drive shaft, loss of rotor
drive, and subsequent loss of control of the helicopter.
This NPRM would retain the requirements of AD 2017-07-02 but would
require that some of the inspections be repeated every 100 hours TIS or
400 hours TIS. Repeating these inspections is necessary to detect and
prevent the unsafe condition. Because these proposed requirements are
for longer intervals, we are providing the public an opportunity to
comment.

FAA's Determination

We are proposing this AD because we evaluated all the relevant
information and determined the unsafe condition described previously is
likely to exist or develop in other products of these same type
designs.

Related Service Information

We reviewed Appendix B to Sikorsky S-330 Model 269D Helicopter
Basic Handbook of Maintenance Instructions No. CSP-D-2, dated February
1, 1993, and revised October 15, 2014; and Appendix B to Sikorsky S-333
Model 269D Config. ``A'' Helicopter Basic Handbook of Maintenance
Instructions No. CSP-D-9, dated July 20, 2001, and revised October 15,
2014. This service information specifies repetitive inspection
procedures, overhaul and retirement schedules, and weight and balance
procedures. The Airworthiness Limitations section, which is included in
this service information, contains the life limits for drive shaft
assembly P/Ns SKCP2738-5 and SKCP2738-7.
We also reviewed Sikorsky 269D Helicopter Alert Service Bulletin
DB-052, Basic Issue, dated January 16, 2014, which distributes the
service life reduction information and implements a new 1,200-hour
overhaul inspection for drive shaft assembly P/Ns SKCP2738-3, SKCP2738-
5, and SKCP2738-7.

Proposed AD Requirements

This proposed AD would require, before further flight:
Removing from service any engine side drive shaft P/N
SKCP2738-7 and pulley side drive shaft P/N SKCP2738-5 that has reached
or exceeded its new life limit as follows:
- 6,000 hours TIS for Model 269D helicopters;
- 1,200 hours TIS for Model 269D Configuration A helicopters;
and
- 1,200 hours TIS if the parts have ever been interchanged
between the two model configurations.
This proposed AD would also require:
Within 25 hours TIS, and thereafter at intervals not to
exceed 25 hours TIS, inspecting the lower pulley to engine alignment,
and if there is any interference with the rotation of the belt drive
alignment tool, adjusting the engine elevation alignment before further
flight.
Within 25 hours TIS, and thereafter at intervals not to
exceed 100 hours TIS, inspecting the KAflex drive shaft alignment and
inspecting the engine side and pulley side drive shafts for a crack,
any corrosion or pitting, a nick, a dent, and a scratch.
Within 25 hours TIS, and thereafter at intervals not to
exceed 400 hours TIS, inspecting each joint for movement; inspecting
each joint for fretting corrosion and each frame and mount bolt torque
stripe for movement; and inspecting each joint for fretting, for a
crack around both the bolt head and washer side, and around the nut and
washer side, and each inside and outside corner radii and radii edges
on both sides of each frame for a crack.
If the drive shaft fails any of the above inspections, this
proposed AD would require replacing both the engine side and pulley
side drive shafts before further flight.
This proposed AD also specifies installing KAflex engine side
coupling assembly P/N SKCP2738-9 and KAflex pulley side coupling
assembly P/N SKCP2738-101 as an optional terminating action for the
requirements of this AD.

Differences Between This Proposed AD and the Service Information

The Sikorsky service information specifies a drive shaft assembly
service life of 3,000 hours TIS with a 1,200 hour overhaul inspection
for Model 269D Configuration A helicopters, while this proposed AD
specifies a service life of 1,200 hours TIS.
The Sikorsky service information specifies different inspection
procedures if there is spline engagement interference or resistance
while inspecting the drive shaft alignment. This proposed AD specifies
replacing both the engine side and pulley side drive shafts if there is
any spline engagement interference or resistance.
The Sikorsky service information specifies inspecting the working
fastener condition without any specific succeeding action regarding the
inspection. This proposed AD specifies replacing both the engine side
and pulley side drive shafts if there is any joint movement.
The Sikorsky service information specifies returning the drive
shaft assembly to Sikorsky if there is fretting dust or red metallic
residue at a joint. This proposed AD specifies replacing both the
engine side and pulley side drive shafts if there is any fretting
corrosion.

Costs of Compliance

We estimate that this proposed AD would affect 18 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.
Removing the engine side and pulley side drive shafts that have
reached the new life limit would take about 4 work-hours for a cost of
$340 per helicopter. Inspecting the lower pulley to engine alignment
using the belt alignment tool would take about 0.5 work-hour for an
estimated cost of $43 per helicopter and $774 for the U.S. fleet per
inspection cycle. Adjusting the engine elevation alignment would take
about 0.5 work-hour for an estimated cost of $43 per helicopter.
Inspecting the drive shaft alignment by checking spline engagement
would take about 1 work-hour for a cost of $85 per helicopter and
$1,530 for the U.S. fleet per inspection cycle. Inspecting the drive
shafts for damage would take about 1 work-hour for an estimated cost of
$85 per helicopter and $1,530 for the U.S. fleet per inspection cycle.
Inspecting the joints would take about 1 work-hour for an estimated
cost of $85 per helicopter and $1,530 for the U.S. fleet per inspection
cycle. Replacing the engine side and pulley side drive shafts, if
required, would take about 8 work-hours and parts would cost about
$20,000, for an estimated cost of $20,680 per helicopter.

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

We determined that this proposed AD would not have federalism
implications under Executive Order 13132. This proposed AD would 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, I certify this proposed regulation:
1. Is not a ``significant regulatory action'' under Executive Order
12866;
2. Is not a ``significant rule'' under the 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 proposed 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.

The Proposed Amendment

Accordingly, under the authority delegated to me by the
Administrator, the FAA proposes to amend 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 removing Airworthiness Directive (AD)
2017-07-02, Amendment 39-18840 (82 FR 15120, March 27, 2017), and
adding the following new AD: