DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2016-9291; Directorate Identifier 2016-SW-004-AD;
Amendment 39-18840; AD 2017-07-02]
RIN 2120-AA64

Airworthiness Directives; Sikorsky Aircraft Corporation
Helicopters

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule; request for comments.

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SUMMARY: We are adopting a new airworthiness directive (AD) for
Sikorsky Aircraft Corporation (Sikorsky) Model 269D and Model 269D
Configuration A helicopters. This AD requires reducing the life limit
of and inspecting certain drive shafts. This AD is prompted by four
incidents involving failure of a drive shaft. The actions specified by
this AD are intended to prevent the unsafe condition on these products.

DATES: This AD becomes effective April 11, 2017.
We must receive comments on this AD by May 26, 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-2016-
9291; 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
(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 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 the
referenced 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 Aircraft Certification Office, Engine & Propeller
Directorate, FAA, 1200 District Avenue, Burlington, Massachusetts
01803; telephone (781) 238-7761; email michael.schwetz@faa.gov.

SUPPLEMENTARY INFORMATION:

Comments Invited

This AD is a final rule that involves requirements affecting flight
safety, and we did not provide you with notice and an opportunity to
provide your comments prior to it becoming effective. However, 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 resulted
from adopting this AD. The most helpful comments reference a specific
portion of the AD, 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 them 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 rulemaking during the
comment period. We will consider all the comments we receive and may
conduct additional rulemaking based on those comments.

Discussion

We are adopting a new AD for Sikorsky Model 269D and Model 269D
Configuration A helicopters with KAflex drive shaft (engine side) part
number (P/N) SKCP2738-7 and KAflex drive shaft (pulley side) P/N
SKCP2738-5 installed. This AD is prompted by four incidents involving
failure of the engine side drive shaft. Three incidents experienced
loss of rotor drive resulting in forced landings. The fourth incident
resulted in vibration during flight prompting an immediate landing. A
fractured engine side drive shaft was evident in each incident.
Investigations revealed compression of the rubber engine mounts may
lead to loss of alignment between the lower pulley shaft and the engine
output shaft, resulting in fracture of the engine side drive shaft.
Additionally, it has been discovered that increased cyclic torsional
loading was inaccurately applied in previous fatigue analysis, making
it necessary to reduce the life limit.
Accordingly, this AD requires reducing the life limit of the engine
side drive shaft and pulley side drive shaft to 6,000 hours time-in-
service (TIS) for Model 269D helicopters and 1,200 hours TIS for Model
269D Configuration A helicopters. If the drive shaft is interchanged or
has ever been interchanged between the two model configurations, this
AD requires using the lower life limit of 1,200 hours TIS. This AD also
requires performing several inspections of the drive shaft within 25
hours TIS and, depending on the results of these inspections, replacing
both the engine side and pulley side drive shafts.
The actions specified by this AD are intended to prevent failure of
the drive shaft, loss of rotor drive, and subsequent loss of control of
the helicopter. Additional inspections at longer intervals may also be
necessary. We plan to publish a notice of proposed rulemaking to give
the public an opportunity to comment on those long-term requirements.

Record of Ex Parte Communication

In preparation of AD actions such as notices of proposed rulemaking
and immediately adopted final rules, it is the practice of the FAA to
obtain technical information and information on the operational and
economic impact from design approval holders and aircraft operators. We
discussed certain aspects of this AD by email and telephone with
Sikorsky. A copy of each email contact and a discussion of each
telephone contact can be found in the rulemaking docket. For
information on locating the docket, see ``Examining the AD Docket.''

FAA's Determination

We are issuing 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 the 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.

AD Requirements

This AD requires, 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 AD also requires, within 25 hours TIS:
Inspecting the KAflex drive shaft alignment.
Inspecting the engine side and pulley side drive shafts
for a crack, any corrosion or pitting, a nick, a dent, and a scratch.
Inspecting each bolted joint (joint) for movement.
Inspecting each joint for fretting corrosion and each
frame and mount bolt torque stripe for movement.
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 AD
requires replacing both the engine side and pulley side drive shafts
before further flight.
Lastly, this AD requires 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.
This 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 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 AD specifies a
service life of 1,200 hours TIS.
This AD specifies several inspections with a compliance time of 25
hours TIS that are currently recurring inspections at 100-hour or 400-
hour intervals in Sikorsky's service information.
The Sikorsky service information specifies different inspection
procedures if there is spline engagement interference or resistance
while inspecting the drive shaft alignment. This 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 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 AD specifies replacing both the engine side
and pulley side drive shafts if there is any fretting corrosion.

Interim Action

We consider this AD interim action. If final action is later
identified, we might consider further rulemaking then.

Costs of Compliance

We estimate that this AD affects 18 helicopters of U.S. Registry.
We estimate that operators may incur the following costs 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 will take about 4 work-hours for a cost of $340 per helicopter.
Inspecting the drive shaft alignment will take about 1 work-hour for a
cost of $85 per helicopter and $1,530 for the U.S. fleet. Inspecting
the drive shafts for damage will take about 1 work-hour for an
estimated cost of $85 per helicopter and $1,530 for the U.S. fleet.
Inspecting the joints will take about 1 work-hour for an estimated cost
of $85 per helicopter and $1,530 for the U.S. fleet. Replacing the
engine side and pulley side drive shafts, if required, will take about
8 work-hours and parts will cost about $20,000, for an estimated cost
of $20,680 per helicopter. Inspecting the lower pulley to engine
alignment will 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 will take about 0.5 work-hour
for an estimated cost of $43 per helicopter.

FAA's Justification and Determination of the Effective Date

Providing an opportunity for public comments prior to adopting
these AD requirements would delay implementing the safety actions
needed to correct this known unsafe condition. Therefore, we find that
the risk to the flying public justifies waiving notice and comment
prior to the adoption of this rule because some of the required
corrective actions must be completed before further flight.
Since an unsafe condition exists that requires the immediate
adoption of this AD, we determined that notice and opportunity for
public comment before issuing this AD are impracticable and contrary to
the public interest and that good cause exists for making this
amendment effective in less than 30 days.

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 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, 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):