[Federal Register Volume 86, Number 241 (Monday, December 20, 2021)]
[Rules and Regulations]
[Pages 71815-71818]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-27409]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-0214; Project Identifier 2018-CE-064-AD; Amendment 
39-21839; AD 2021-24-18]
RIN 2120-AA64


Airworthiness Directives; Viking Aircraft Limited Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for all 
Viking Air Limited Model DHC-3 airplanes. This 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 identifies the unsafe 
condition as fatigue damage of the wing strut lug fitting components 
and the fuselage to wing strut attachment (tie-bar). This AD requires 
determining service life limits

[[Page 71816]]

for the wing strut fitting on the main spar and for the tie-bar and 
following instructions for removal and replacement of affected parts. 
The FAA is issuing this AD to address the unsafe condition on these 
products.

DATES: This AD is effective January 24, 2022.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in this AD as of January 24, 
2022.

ADDRESSES: For service information identified in this final rule, 
contact Viking Air Limited Technical Support, 1959 De Havilland Way, 
Sidney, British Columbia, Canada, V8L 5V5; phone: (North America) (800) 
663-8444; fax: (250) 656-0673; email: [email protected]; 
website: https://www.vikingair.com/support/service-bulletins. You may 
view this service information at the FAA, Airworthiness Products 
Section, Operational Safety Branch, 901 Locust, Kansas City, MO 64106. 
For information on the availability of this material at the FAA, call 
(816) 329-4148. It is also available at https://www.regulations.gov by 
searching for and locating Docket No. FAA-2021-0214.

Examining the AD Docket

    You may examine the AD docket at https://www.regulations.gov by 
searching for and locating Docket No. FAA-2021-0214; 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 
MCAI, any comments received, and other information. The address for 
Docket Operations 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: Aziz Ahmed, Aviation Safety Engineer, 
New York ACO Branch, FAA, 1600 Stewart Avenue, Suite 410, Westbury, NY 
11590; phone: (516) 287-7329; fax: (516) 794-5531; email: 
[email protected].

SUPPLEMENTARY INFORMATION:

Background

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 by adding an AD that would apply to all Viking Air Limited 
Model DHC-3 airplanes. The NPRM published in the Federal Register on 
June 28, 2021 (86 FR 33916). The NPRM was prompted by MCAI originated 
by Transport Canada, which is the aviation authority for Canada. 
Transport Canada has issued AD CF-2017-29, dated August 24, 2017 
(referred to after this as ``the MCAI''), to correct an unsafe 
condition for Viking Air Limited Model DHC-3 airplanes. The MCAI 
states:

    It has been determined that the current maintenance program does 
not adequately address potential fatigue damage of the wing strut 
lug fitting components or the fuselage to wing strut attachment (Tie 
Bar). Affected parts must be replaced before specified air time 
limits are reached to avoid fatigue cracking of the affected parts. 
Cracking which is not detected may compromise the structural 
integrity of the wing or the Tie-Bar.
    Fatigue damage occurs more rapidly on aeroplanes that are 
operated at higher gross weights. For that reason, the corrective 
actions of this [Transport Canada] AD must be accomplished sooner 
for aeroplanes that have been certified for operation at higher 
gross weights.
    Fatigue damage also occurs more rapidly on aeroplanes that are 
operated below 2000 feet above ground level (AGL) over land due to 
higher and more frequent gust and maneuvering loads. Low level 
flights over water are not known to produce increased fatigue damage 
on the DHC-3. For that reason, the corrective actions of this 
[Transport Canada] AD must be accomplished sooner for aeroplanes 
that have been operated at low altitudes over land.

    This condition, if not addressed, could result in cracking and 
failure of the structural integrity of the wing or the tie-bar.
    You may examine the MCAI in the AD docket at https://www.regulations.gov by searching for and locating Docket No. FAA-2021-
0214.
    In the NPRM, the FAA proposed to require determining service life 
limits for the wing strut fitting on the main spar and for the tie-bar 
and following instructions for removal and replacement of affected 
parts. The FAA is issuing this AD to address the unsafe condition on 
these products.

Discussion of Final Airworthiness Directive

Comments

    The FAA received comments from two commenters. The commenters were 
Talkeetna Air Taxi Inc. (Talkeetna Air) and Rust's Flying Service/K2 
Aviation (Rust's Flying Service). The following presents the comments 
received on the NPRM and the FAA's response to each comment.

Request Regarding Equivalent Air Time

    Both commenters requested the FAA change the proposed method of 
calculating equivalent air time by doubling the total hours on each 
component. Talkeetna Air requested the FAA allow increased visual and 
non-destructive testing inspections instead. Talkeetna Air and Rust's 
Flying Service suggested the FAA allow operators to calculate by using 
the formula and estimating the altitudes at which an airplane has 
operated, as provided in the service information, instead of by 
assuming all operations occur below 2,000 feet. Rust's Flying Service 
stated it has data to verify the operating altitudes of its aircraft.
    As the FAA explained in the NPRM, there is no regulatory 
requirement for owners or operators to record or maintain the operating 
altitude history of an airplane. As a result, this AD requires 
calculating the compliance time by assuming all operations occurred 
below 2,000 feet AGL (and therefore doubling the total hours). However, 
operators may request approval to determine equivalent air time 
differently as an alternative method of compliance under the provisions 
of paragraph (g)(1) of this AD. The FAA did not change this AD based on 
this comment.

Request Regarding Costs of Compliance

    Talkeetna Air requested that the FAA adjust its estimated costs of 
compliance. The commenter stated that the hourly rate and number of 
estimated labor hours is too low for what would be required.
    The FAA obtained the 300-hour labor time estimated in the NPRM from 
Viking Air Limited DHC-3 Otter Service Bulletin Number V3/0008, 
Revision NC, dated February 9, 2017. The FAA verified this number with 
Viking Air Limited and confirmed it is valid.
    The FAA Office of Aviation Policy and Plans provides the labor rate 
of $85 per work-hour for the FAA to use when estimating the labor costs 
of complying with AD requirements.
    The FAA did not change this AD based on this comment.

Conclusion

    This product has been approved by the aviation authority of another 
country and is approved for operation in the United States. Pursuant to 
the FAA's bilateral agreement with this State of Design Authority, it 
has notified the FAA of the unsafe condition described in the MCAI 
referenced above. The FAA reviewed the relevant data, considered any 
comments received, and determined that air safety requires adopting 
this AD as proposed. Accordingly, the FAA is issuing this AD to address 
the unsafe condition on these products. This AD is adopted as proposed 
in the NPRM.

[[Page 71817]]

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Viking DHC-3 Otter Service Bulletin Number V3/
0008, Revision NC, dated February 9, 2017. The service information 
specifies determining service life limits for the wing strut fitting on 
the main spar and for the tie-bar and contains instructions for removal 
and replacement. The FAA also reviewed De Havilland Aircraft of Canada, 
Limited DHC-3 Otter Service Bulletin Number 3/37, Revision B, dated 
October 8, 1982. The service information specifies instructions for 
removing and replacing the fuselage to wing strut attachment tie-bar. 
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 ADDRESSES.

Differences Between This AD and the MCAI

    The MCAI requires calculating the compliance time by using a 
formula and estimating the altitudes at which an airplane has operated. 
The MCAI also instructs operators to assume operations below 2,000 feet 
AGL when the operating altitude of the airplane is unknown. Because the 
FAA has no regulatory requirement for owners or operators to record or 
maintain the operating altitude history of an airplane, this AD 
requires calculating the compliance time by assuming all operations 
occurred below 2,000 feel AGL.

Costs of Compliance

    The FAA estimates that this AD affects 41 airplanes of U.S. 
registry.
    The FAA also estimates that it would take about 300 work-hours per 
airplane to replace both the wing strut fitting and the tie-bar. The 
average labor rate is $85 per work-hour. Required parts would cost 
about $5,599 per airplane.
    Based on these figures, the FAA estimates the cost of this AD on 
U.S. operators to be $1,275,059 or $31,099 per airplane.

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.

Regulatory Findings

    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) Will not affect intrastate aviation in Alaska, and
    (3) 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 Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
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]

0
2. The FAA amends Sec.  39.13 by adding the following new airworthiness 
directive:

2021-24-18 Viking Air Limited: Amendment 39-21839; Docket No. FAA-
2021-0214; Project Identifier 2018-CE-064-AD.

(a) Effective Date

    This airworthiness directive (AD) is effective January 24, 2022.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Viking Air Limited Model DHC-3 airplanes, all 
serial numbers, certificated in any category.

(d) Subject

    Joint Aircraft System Component (JASC) Code 5700, Wing 
Structure.

(e) Unsafe Condition

    This AD was prompted by 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 fatigue damage 
of the wing strut lug fitting components or the fuselage to wing 
strut attachment (tie-bar). The FAA is issuing this AD to identify 
and correct potential fatigue damage of the wing strut lug fitting 
components of the fuselage to wing strut attachment. The unsafe 
condition, if not addressed, could result in cracking and failure of 
the structural integrity of the wing or the tie-bar.

(f) Actions and Compliance

    Unless already done, do the following actions in paragraphs 
(f)(1) through (3) of this AD:
    (1) For all airplanes: Within 3 months after the effective date 
of this AD, determine and record the number of equivalent air time 
hours on each wing and tie-bar by doubling the total hours time-in-
service (TIS) accumulated on each part. If the total hours TIS of a 
tie-bar is unknown or cannot be determined, use the total hours TIS 
of the wing strut lug fitting on the main spar.
    (2) For airplanes with a maximum certificated gross weight that 
has never exceeded 8,000 pounds: Remove from service each left-hand 
and right-hand wing strut fitting and tie-bar by following the 
Accomplishment Instructions in Viking DHC-3 Otter SB V3/0008, 
Revision NC, dated February 9, 2017, and the Replacement section of 
the Accomplishment instructions in De Havilland Aircraft of Canada, 
Limited DHC-3 Otter Service Bulletin Number 3/37, Revision B, dated 
October 8, 1982, at whichever of the following compliance times that 
occurs later:
    (i) Before the part accumulates 40,000 equivalent air time 
hours, or
    (ii) Within 12 months after the effective date of this AD.
    (3) For airplanes with a maximum certificated gross weight that 
has ever exceeded 8,000 pounds: Remove from service each left-hand 
and right-hand wing strut fitting and tie-bar by following the 
Accomplishment Instructions in Viking DHC-3 Otter SB V3/0008, 
Revision NC, dated February 9, 2017, and the Replacement section of 
the Accomplishment instructions in De Havilland Aircraft of Canada, 
Limited DHC-3 Otter Service Bulletin Number 3/37, Revision B, dated 
October 8, 1982, at whichever of the following compliance times that 
occurs later:
    (i) Before the part accumulates 32,200 equivalent air time 
hours, or
    (ii) Within 12 months after the effective date of this AD.

(g) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, New York ACO Branch, FAA, has the authority to 
approve AMOCs

[[Page 71818]]

for this AD, if requested using the procedures found in 14 CFR 
39.19. In accordance with 14 CFR 39.19, send your request to your 
principal inspector or local Flight Standards District Office, as 
appropriate. If sending information directly to the manager of the 
ACO Branch, send it to the attention of the person identified in 
paragraph (h)(1) of this AD.
    (2) Before using any approved AMOC, notify your appropriate 
principal inspector, or lacking a principal inspector, the manager 
of the local flight standards district office/certificate holding 
district office.

(h) Related Information

    (1) For more information about this AD, contact Aziz Ahmed, 
Aviation Safety Engineer, New York ACO Branch, FAA, 1600 Stewart 
Avenue, Suite 410, Westbury, NY 11590; phone: (516) 287-7329; fax: 
(516) 794-5531; email: [email protected].
    (2) Refer to Transport Canada AD CF-2017-29, dated August 24, 
2017, for more information. You may examine the Transport Canada AD 
at https://www.regulations.gov by searching for and locating Docket 
No. FAA-2021-0214.

(i) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference (IBR) of the service information listed 
in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this service information as applicable to do 
the actions required by this AD, unless the AD specifies otherwise.
    (i) Viking DHC-3 Otter Service Bulletin Number V3/0008, Revision 
NC, dated February 9, 2017.
    (ii) De Havilland Aircraft of Canada, Limited DHC-3 Otter 
Service Bulletin Number 3/37, Revision B, dated October 8, 1982.
    Note to paragraph (i)(2)(ii): Although De Havilland Aircraft of 
Canada Limited DHC-3 Otter Service Bulletin Number 3/37, Revision B, 
dated October 8, 1982, is at revision B, the footer on pages 3 
through 6 shows revision ``A,'' dated May 14, 1982.
    (3) For both Viking and De Havilland Aircraft of Canada, Limited 
service information identified in this AD, contact Viking Air 
Limited Technical Support, 1959 De Havilland Way, Sidney, British 
Columbia, Canada, V8L 5V5; phone: (North America) (800) 663-8444; 
fax: (250) 656-0673; email: [email protected]; 
website: https://www.vikingair.com/support/service-bulletins.
    (4) You may view this service information at FAA, Airworthiness 
Products Section, Operational Safety Branch, 901 Locust, Kansas 
City, MO 64106. For information on the availability of this material 
at the FAA, call (816) 329-4148.
    (5) You may view this service information that is incorporated 
by reference at the National Archives and Records Administration 
(NARA). For information on the availability of this material at 
NARA, email: [email protected], or go to: https://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued on November 19, 2021.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2021-27409 Filed 12-17-21; 8:45 am]
BILLING CODE 4910-13-P


