DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2015-0096; Directorate Identifier 2014-CE-040-AD;
Amendment 39-18077; AD 2015-02-10]
RIN 2120-AA64

Airworthiness Directives; Viking Air Limited Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule; request for comments.

-----------------------------------------------------------------------

SUMMARY: We are adopting a new airworthiness directive (AD) for Viking
Air Limited Models DHC-2 Mk. I, DHC-2 Mk. II, and DHC-2 Mk. III
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 failed locknuts on the
horizontal stabilizer attach bracket. We are issuing this AD to require
actions to address the unsafe condition on these products.

DATES: This AD is effective February 18, 2015.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in the AD as of February 18,
2015.
We must receive comments on this AD by March 16, 2015.

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.
For service information identified in this AD, contact Viking Air
Limited Technical Support, 1959 De Havilland Way, Sidney, British
Columbia, Canada, V8L 5V5; Fax: 250-656-0673; telephone: (North
America) 1-800-663-8444; email: technical.support@vikingair.com;
Internet: http://www.vikingair.com/support/service-bulletins. You may
view this referenced service information at the FAA, Small Airplane
Directorate, 901 Locust, Kansas City, Missouri 64106. For information
on the availability of this material at the FAA, call (816) 329-4148.

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-2015-
0096; or in person at the Docket Management Facility 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 the Docket Office (telephone
(800) 647-5527) is in the ADDRESSES section. Comments will be available
in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Aziz Ahmed, Aerospace Safety Engineer,
FAA, New York Aircraft Certification Office (ACO), 1600 Steward Avenue,
Suite 410, Westbury, New York 11590; telephone: (516) 228-7329; fax:
(516) 794-5531; email: aziz.ahmed@faa.gov.

SUPPLEMENTARY INFORMATION:

Discussion

Transport Canada, which is the aviation authority for Canada, has
issued AD No. CF-2014-38, dated October 20, 2014 (referred to after
this as ``the MCAI''), to correct an unsafe condition for Viking Air
Limited Models DHC-2 Mk. I, DHC-2 Mk. II, and DHC-2 Mk. III airplanes.
The MCAI states:

There has been an in-service report of failed MS21042 locknuts
on the horizontal stabilizer attach bracket of a DHC-2 Mk. I
aeroplane. Laboratory examinations of these nuts found intergranular
fractures typical of hydrogen embrittlement possibly due to the
introduction of hydrogen during the manufacturing process.
Failure of these nuts could result in detachment of the
horizontal stabilizer and loss of control of the aeroplane.
This AD mandates the inspection and replacement, of the
horizontal stabilizer attach bracket MS21042 locknuts.

You may examine the MCAI on the Internet at http://www.regulations.gov
by searching for and locating Docket No. FAA-2015- 0096.

Relevant Service Information

Viking Air Limited has issued Viking Alert Service Bulletin No. V2/
0007, Revision `NC', dated April 29, 2013. The actions described in
this service information are intended to correct the unsafe condition
identified in the MCAI. The service bulletin describes procedures to
inspect and replace the horizontal stabilizer attach bracket locknuts.
You can find this service information on the Internet at http://www.
regulations.gov by searching for and locating Docket No. FAA-2015-
0096.

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. We are 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 any locknut on the horizontal stabilizer attach bracket
could result in detachment of the horizontal stabilizer and consequent
loss of control. Therefore, we determined that notice and opportunity
for public comment before issuing this AD are impracticable and that
good cause exists for making this amendment effective in fewer than 30
days.

Comments Invited

This AD is a final rule that involves requirements affecting flight
safety, and we did not precede it by notice and opportunity for public
comment. We invite 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-2015-0096; Directorate
Identifier 2014-CE-040-AD'' at the beginning of your comments. We
specifically invite comments on the overall regulatory, economic,
environmental, and energy aspects of this AD. We will consider all
comments received by the closing date and may
amend this AD because of those comments.
We will post all comments we receive, without change, to http://www.
regulations.gov, including any personal information you provide. We
will also post a report summarizing each substantive verbal contact we
receive about this AD.

Costs of Compliance

We estimate that this AD will affect 35 products of U.S. registry.
We also estimate that it would take about 1 work-hour per product to
comply with the basic requirements of this AD. The average labor rate
is $85 per work-hour.
Based on these figures, we estimate the cost of the AD on U.S.
operators to be $2,975, or $85 per product.
In addition, we estimate that any necessary follow-on actions would
take about 12 work-hours and require parts costing $2 per locknut, or
$12 for a maximum of 6 locknuts, for a cost of $1,032 per product. We
have 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.
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 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 AD: