DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2018-0638; Product Identifier 2018-NM-016-AD; Amendment
39-19552; AD 2019-02-05]
RIN 2120-AA64

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

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

ACTION: Final rule.

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SUMMARY: We are superseding Airworthiness Directive (AD) 2013-11-03,
which applied to certain Viking Air Limited Model CL-215-1A10 and CL-
215-6B11 (CL-215T Variant) airplanes. AD 2013-11-03 required repetitive
detailed inspections for cracking of the left-hand (LH) and right-hand
(RH) wing lower skin, and repair if necessary. This AD requires
repetitive borescope inspections of the LH and RH wing lower skin and
repetitive eddy current inspections of the LH and RH wing front and
rear lower spar caps. This AD was prompted by reports of a fractured
wing lower rear spar cap and reinforcing strap and a report of cracking
of the wing lower skin and rear spar. We are issuing this AD to address
the unsafe condition on these products.

DATES: This AD is effective March 22, 2019.
The Director of the Federal Register approved the incorporation by
reference of a certain publication listed in this AD as of March 22,
2019.

ADDRESSES: For service information identified in this final rule,
contact Viking Air Limited, 1959 de Havilland Way, Sidney, British
Columbia V8L 5V5, Canada; telephone +1-250-656-7227; fax +1-250-656-
0673; email acs-technical.publications@vikingair.com; internet http://www.
vikingair.com. You may view this referenced service information at
the FAA, Transport Standards Branch, 2200 South 216th St., Des Moines,
WA. For information on the availability of this material at the FAA,
call 206-231-3195. It is also available on the internet at http://www.
regulations.gov by searching for and locating Docket No. FAA-2018-0638.

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-2018-
0638; 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 final rule, the regulatory evaluation, any comments received, and
other information. The address for Docket Operations (phone: 800-647-
5527) is U.S. Department of Transportation, Docket Operations, M-30,
West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE,
Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: Andrea Jimenez, Aerospace Engineer,
Airframe and Mechanical Systems Section, FAA, New York ACO Branch, 1600
Stewart Avenue, Suite 410, Westbury, NY 11590; telephone 516-228-7330;
fax 516-794-5531.

SUPPLEMENTARY INFORMATION:

Discussion

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR
part 39 to supersede AD 2013-11-03, Amendment 39-17463 (78 FR 32353,
May 30, 2013) (``AD 2013-11-03''). AD 2013-11-03 applied to certain
Viking Air Limited Model CL-215-1A10 and CL-215-6B11 (CL-215T Variant)
airplanes. The NPRM published in the Federal Register on August 2, 2018
(83 FR 37768). The NPRM was prompted by reports of a fractured wing
lower rear spar cap and reinforcing strap and a report of cracking of
the wing lower skin and rear spar. The NPRM proposed to require
repetitive borescope inspections of the LH and RH wing lower skin and
repetitive eddy current inspections of the LH and RH wing front and
rear lower spar caps. We are issuing this AD to address cracked wing
structure, which could result in failure of the wing.
Transport Canada Civil Aviation (TCCA), which is the aviation
authority for Canada, has issued Canadian AD CF-2013-11R1, dated
October 16, 2017 (referred to after this as the Mandatory Continuing
Airworthiness Information, or ``the MCAI''), to correct an unsafe
condition for certain Viking Air Limited Model CL-215-1A10 and CL-215-
6B11 (CL-215T Variant) airplanes. The MCAI states:

While performing modifications on a CL-215-1A10 aeroplane, an
operator discovered that the wing lower rear spar cap and
reinforcing strap were fractured at Wing Stations (WS) 49.5 and 50
respectively and the rear spar web and wing lower skin were also
cracked. It is suspected that a crack initiated at the wing lower
spar cap, leading to its failure, the subsequent failure of the
reinforcing strap and cracking of the spar web and wing lower skin.
The damage was outside of the area addressed by the repetitive
ultrasonic inspections required by [Canadian] AD CF-1992-26R2 [which
corresponds to FAA AD 2012-11-04, Amendment 39-17067 (77 FR 32892,
June 4, 2012)] and was found 95 hours air time after the last
ultrasonic inspection.
Failure and cracking of the above-noted wing structure, if not
detected, could result in failure of the wing.
In order to mitigate the unsafe condition, [Canadian] AD CF-
2013-11 [which corresponds to FAA AD 2013-11-03] was released.
However, further analysis has indicated the need for repetitive eddy
current and borescope inspections. Therefore, Revision 1 of this
[Canadian] AD mandates a repetitive detailed inspection of the wing
lower skin using a borescope, changes the one-time eddy current
inspection of the lower front and rear spar caps to a repetitive
inspection and eliminates the one-time detailed inspection with fuel
bladders removed.
The requirements of [Canadian] AD CF-1992-26R2 remain
applicable.

You may examine the MCAI in the AD docket on the internet at http://www.
regulations.gov by searching for and locating Docket No. FAA-2018-0638.

Comments

We gave the public the opportunity to participate in developing
this final rule. The following presents the comment received on the
NPRM and the FAA's response to that comment.

Request To Use Time-in-Service Hours Rather Than Flight Hours

The commenter, Adam Geber, recommended using time-in-service hours
instead of flight hours in the proposed AD. The commenter stated that
maintenance hourly requirements are based on time-in-service rather
than flight time, as defined in 14 CFR 1.1. The commenter further
asserted that the term ``flight hour'' is not defined in 14 CFR 1.1,
and that many 14 CFR part 91 regulations prescribe hourly maintenance
requirements based on time-in-service, with no requirement to track
flight time for maintenance purposes.
We disagree with the commenter's recommended changes, because
flight hours, which are in current use and well understood in the
aviation industry, are the most effective way of addressing the unsafe
condition identified in this AD. Flight hours were used in the
engineering evaluation for this AD, and the required actions of this AD
are based on that evaluation. The use of flight hours in this AD is
also in keeping with the previous related ADs, which use that measure
for compliance times and inspection intervals. Additionally, since
flight hours are used in this AD, operators are required to track them.
AD requirements are not restricted by the definitions in 14 CFR 1.1 or
the part 91 regulations quoted by commenter. We have not changed this
AD in this regard.

Explanation of Change to Manufacturer Name Specified in AD 2013-11-03

We have revised references to the aircraft manufacturer name
specified in AD 2013-11-03 throughout this final rule to identify the
aircraft manufacturer name as published in the most recent type
certificate data sheet (TCDS) for the affected models.

Conclusion

We reviewed the relevant data, considered the comment received, and
determined that air safety and the public interest require adopting
this final rule with the change described previously and minor
editorial changes. We have determined that these minor changes:
Are consistent with the intent that was proposed in the
NPRM for addressing the unsafe condition; and
Do not add any additional burden upon the public than was
already proposed in the NPRM.
We also determined that these changes will not increase the
economic burden on any operator or increase the scope of this final
rule.

Related Service Information Under 1 CFR Part 51

Bombardier has issued Alert Service Bulletin 215-A558, Revision 3,
dated June 3, 2016. This service information describes procedures for
detecting cracks using repetitive borescope inspections of the LH and
RH wing lower skin and repetitive eddy current inspections of the LH
and RH wing front and rear lower spar caps. 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.

Costs of Compliance

We estimate that this AD affects 4 airplanes of U.S. registry. We
estimate the following costs to comply with this AD:

Estimated Costs

We have received no definitive data that would enable us to provide
cost estimates for the on-condition actions specified in this AD.

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 transport category airplanes and
associated appliances to the Director of the System Oversight Division.

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 removing Airworthiness Directive (AD)
2013-11-03, Amendment 39-17463 (78 FR 32353, May 30, 2013), and adding
the following new AD: