DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2019-0410; Product Identifier 2018-CE-059-AD; Amendment
39-19644; AD 2019-10-05]
RIN 2120-AA64

Airworthiness Directives; Viking Air Limited (Type Certificate
Previously Held by Bombardier Inc.; de Havilland, Inc.) Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule; request for comments.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for all
Viking Air Limited (Viking) Models DHC-6-1, DHC-6-100, DHC-6-200, DHC-
6-300, and DHC-6-400 airplanes. This AD results from mandatory
continuing airworthiness information (MCAI) issued by the aviation
authority of another country to identify and correct an unsafe
condition on an aviation product. The MCAI describes the unsafe
condition as occurrences of excessive wear of elevator cables at pulley
location station (STA) 270.3. The FAA is issuing this AD to require
actions to address the unsafe condition on these products.

DATES: This AD is effective June 20, 2019.
The FAA must receive comments on this AD by July 15, 2019.

ADDRESSES: You may send comments by any of the following methods:
Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions
for submitting comments.
Fax: (202) 493-2251.
Mail: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue SE, Washington, DC 20590.
Hand Delivery: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue SE, Washington, DC 20590, 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-2019-0410;
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, the regulatory evaluation, any comments received, and other
information. The street address for Docket Operations (telephone (800)
647-5527) is listed above. Comments will be available in the AD docket
shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Darren Gassetto, Aerospace Engineer,
Mechanical Systems and Admin Services Section, FAA, New York ACO
Branch, 1600 Stewart Avenue, Suite 410, Westbury, New York 11590;
telephone: (516) 228-7323; fax: (516) 794-5531; email: 9-avs-nyaco-cos@faa.gov.

SUPPLEMENTARY INFORMATION:

Discussion

Transport Canada, which is the aviation authority for Canada, has
issued AD Number CF-2018-28, dated October 15, 2018 (referred to after
this as ``the MCAI''), to correct an unsafe condition for all Viking
(formerly Bombardier Inc.; de Havilland, Inc.) Models DHC-6-1, DHC-6-
100, DHC-6-110, DHC-6-200, DHC-6-210, DHC-6-300, DHC-6-310, DHC-6-320,
and DHC-6-400 airplanes. The MCAI states:

There have been several occurrences of excessive wear of
elevator cables at the STA 270.3 pulleys. In one case the cable
failed in flight leading to an emergency landing. Viking Air Ltd.,
(Viking) has determined that excessive wear can be caused by a
damaged pulley. Elevator cable wear that is not detected can lead to
failure of the cable and loss of control of the aeroplane.

The damage to the elevator control cable is caused by a dent on the
pulley on the inside bearing race that is not detectable by direct
visual inspection or rotation of the pulley without applied load. The
dent in the bearing race prevents free turning of the pulley under
certain load conditions, which causes rapid wear of the cable. The dent
is caused by wear over an extended period of time due to vibration
while the bearing is stationary. This AD requires inspecting the
elevator and rudder control cables for abnormal wear at pulley location
STA 270.3 and replacing any worn cables and the corresponding pulley.
You may examine the MCAI on the internet at http://www.regulations.gov
by searching for and locating Docket No. FAA-2019-0410.

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.
The FAA discussed certain aspects of this AD by email and in person
with Viking Air Limited. A copy of each email contact and a summary of
each discussion can be found in the rulemaking docket. For information
on locating the docket, see ``Examining the AD Docket'' in ADDRESSES.

Related Service Information

The FAA reviewed Viking DHC-6 Twin Otter Service Bulletin Number:
V6/0062, dated July 31, 2017. The service information contains
instructions for inspecting the elevator and rudder control cables for
abnormal wear at pulley location STA 270.3 and replacing any worn
cables and the corresponding pulley.

FAA's Determination and Requirements of the AD

This product has been approved by the aviation authority of another
country, and is approved for operation in the United States. Pursuant
to our bilateral agreement with this State of Design Authority, they
have notified us of the unsafe condition described in the MCAI and
service information referenced above. The FAA is issuing this AD
because we evaluated all information provided by the State of Design
Authority and determined the unsafe condition exists and is likely to
exist or develop on other products of the same type design.

FAA's Determination of the Effective Date

An unsafe condition exists that requires the immediate adoption of
this AD. The FAA has found that the risk to the flying public justifies
waiving notice and comment prior to adoption of this rule because
failure of the elevator or rudder control cable in flight could result
in loss of control of the aircraft. Therefore, the FAA finds good cause
that notice and opportunity for prior public comment are impracticable.
In addition, for the reason(s) stated above, the FAA finds that good
cause exists for making this amendment effective in less than 30 days.

Comments Invited

This AD is a final rule that involves requirements affecting flight
safety, and the FAA did not precede it by notice and opportunity for
public comment. The FAA invites you to send any written relevant data,
views, or arguments about this AD. Send your comments to an address
listed under the ADDRESSES section. Include ``Docket No. FAA-2019-0410;
Product Identifier 2018-CE-059-AD'' at the beginning of your comments.
The FAA specifically invites comments on the overall regulatory,
economic, environmental, and energy aspects of this AD. The FAA will
consider all comments received by the closing date and may amend this
AD because of those comments.
The FAA will post all comments received, without change, to http://www.
regulations.gov, including any personal information you provide.
The FAA will also post a report summarizing each substantive verbal
contact we receive about this AD.

Costs of Compliance

The FAA estimates that this AD will affect 133 products of U.S.
registry. The FAA also estimates that it will take about .5 work-hour
per product to comply with the basic inspection requirement of this AD.
The average labor rate is $85 per work-hour.
Based on these figures, the FAA estimates the cost of the AD on
U.S. operators to be $5,652.50, or $42.50 per product.
In addition, the FAA estimates that any necessary follow-on
replacement action will take about 3 work-hours and require parts
costing $203 for a cost of $458 per product. The FAA has no way of
determining the number of products that may need these actions.

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.
This AD is issued in accordance with authority delegated by the
Executive Director, Aircraft Certification Service, as authorized by
FAA Order 8000.51C. In accordance with that order, issuance of ADs is
normally a function of the Compliance and Airworthiness Division, but
during this transition period, the Executive Director has delegated the
authority to issue ADs applicable to small airplanes, gliders,
balloons, airships, domestic business jet transport airplanes, and
associated appliances to the Director of the Policy and Innovation
Division.

Regulatory Findings

The FAA 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 above, I certify that this AD:
(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, 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.

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):