DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2019-0045; Product Identifier 2018-CE-027-AD]
RIN 2120-AA64

Airworthiness Directives; Viking Air Limited Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of
Transportation (DOT).

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to adopt a new airworthiness directive (AD) for
certain Viking Air Limited Models DHC-2 Mk. I and DHC-2 Mk. III
airplanes. This proposed AD results from mandatory continuing
airworthiness information (MCAI) originated by an aviation authority of
another country to identify and correct an unsafe condition on an
aviation product. The MCAI describes the unsafe condition as cracks
reported on the forward and aft float strut wire pull fittings. We are
issuing this proposed AD to require actions to address the unsafe
condition on these products.

DATES: We must receive comments on this proposed AD by March 28, 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.

For service information identified in this proposed AD, contact
Viking Air Limited Technical Support, 1959 De Havilland Way, Sidney,
British Columbia, Canada, V8L 5V5; telephone: (North America) (800)
663-8444; fax: (250) 656-0673; email: technical.support@vikingair.com;
internet: http://www.vikingair.com/support/service-bulletins. You may
review this referenced service information at the FAA, Policy and
Innovation Division, 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-2019-0045;
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 proposed AD, the regulatory evaluation, any comments received, and
other information. The street address for Docket Operations (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 Engineer, FAA,
New York ACO Branch, 1600 Stewart Avenue, Suite 410, Westbury, New York
11590; telephone: (516) 287-7329; fax: (516) 794-5531; email:
aziz.ahmed@faa.gov.

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to send any written relevant data, views, or
arguments about this proposed AD. Send your comments to an address
listed under the ADDRESSES section. Include "Docket No. FAA-2019-0045;
Product Identifier 2018-CE-027-AD" at the beginning of your comments.
We specifically invite comments on the overall regulatory, economic,
environmental, and energy aspects of this proposed AD. We will consider
all comments received by the closing date and may amend this proposed
AD because of those comments.

We will post all comments we receive, without change, to http://
regulations.gov, including any personal information you provide. We
will also post a report summarizing each substantive verbal contact we
receive about this proposed AD.

Discussion

Transport Canada, which is the aviation authority for Canada, has
issued AD Number CF-2018-10, dated April 18, 2018 (referred to after
this as "the MCAI"), to correct an unsafe condition for certain
Viking Air Limited Models DHC-2 Mk. I and DHC-2 Mk. III airplanes. The
MCAI states:

Cracks have been reported on the Forward and Aft float strut
wire pull fittings on DHC-2 Mk. I aeroplanes equipped with the 5600
lb gross weight increase kit installed in accordance with STC SA92-
63 or SA00299NY and on DHC-2 Mk. III aeroplanes equipped with the
6000 lb gross weight increase kit installed in accordance with STC
SA91-18 or SA945NE. An investigation found that the forward and aft
wire pull fittings (P/N VALTBS1245-1/-2 and P/N VALTBS1244-1,
respectively) are prone to stress corrosion cracking at low cycles/
hours.

Failure of these wire pull fittings will reduce the strength of
the float undercarriage below the required structural capability and
could result in a failure of the undercarriage causing the aeroplane
to tip over and be submerged.

Therefore this AD requires that the forward and aft wire pull
fittings be replaced with P/N VALTBS1245-3/-4 and P/N VALTBS1244-3/-
4 (LH/RH) fittings respectively. These fittings are geometrically
similar to the legacy fittings and are made of a different aluminum
alloy that is less susceptible to stress corrosion cracking.

In addition to replacing the fittings, it is necessary to
implement a recurring visual inspection of the fittings to assure
continuing airworthiness.

You may examine the MCAI on the internet at http://www.regulations.gov by
searching for and locating Docket No. FAA-2019-0045.

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 with Viking. A copy of
these email contacts can be found in the rulemaking docket. For
information on locating the docket, see "Examining the AD Docket."

Related Service Information Under 1 CFR Part 51

Viking has issued Service Bulletin (SB) Number V2/003, Revision NC,
dated November 28, 2012, for Model DCH-2 Mk. I airplanes, and SB Number
V2/002, Revision A, dated September 12, 2011, for Model DCH-2 Mk. III
airplanes. For the applicable airplanes, the service information
describes procedures for replacing the forward and aft float strut wire
pull fittings and specifies implementing repetitive visual inspections
of the fittings. 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
of this NPRM.

FAA's Determination and Requirements of the Proposed 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 proposing this AD because
we evaluated all information and determined the unsafe condition exists
and is likely to exist or develop on other products of the same type
design.

The MCAI requires returning cracked fittings to Viking, and this
proposed AD would not. The MCAI also prohibits installation of an
affected wire pull fitting on any airplane, and this proposed AD would
not.

Costs of Compliance

We estimate that this proposed AD will affect 136 products of U.S.
registry. We also estimate replacing the fittings would take about 12
work-hours at an average labor rate of $85 per work-hour, and required
parts would cost about $2,741. Based on these figures, we estimate a
cost of $3,761 per airplane and $511,496 for the U.S. operator fleet.

Inspecting the fittings would take about .5 work-hour for an
estimated cost of $42.50 per airplane and $5,780 for the U.S. fleet,
per inspection cycle.

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.

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

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 above, 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, 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.

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 adding the following new AD: