[Federal Register Volume 86, Number 242 (Tuesday, December 21, 2021)]
[Proposed Rules]
[Pages 72198-72200]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-27509]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2020-1005; Project Identifier MCAI-2020-00709-A]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for Viking Air Limited (type certificate previously held by Bombardier 
Inc.) Model DHC-3 airplanes with a certain wing strut assembly 
installed. 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 identifies the unsafe condition as fatigue 
damage of the wing struts. This proposed AD would require a bolt hole 
eddy current inspection of the lug plate holes, a visual and 
fluorescent dye penetrant inspection of the lug fittings, and a visual 
and eddy current surface scan inspection of the wing strut assemblies. 
This unsafe condition could lead to failure of the wing strut, which 
could result in an in-flight breakup of the wing. The FAA is proposing 
this AD to address the unsafe condition on these products.

DATES: The FAA must receive comments on this proposed AD by February 4, 
2022.

ADDRESSES: You may send comments, using the procedures found in 14 CFR 
11.43 and 11.45, by any of the following methods:
     Federal eRulemaking Portal: Go to https://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: Deliver to Mail address above between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    For service information identified in this NPRM, contact Viking Air 
Ltd., 1959 de Havilland Way, Sidney British Columbia, Canada V8L 5V5; 
phone: (800) 663-8444; email: [email protected]; 
website: https://www.vikingair.com. 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 (817) 222-5110.

Examining the AD Docket

    You may examine the AD docket at https://www.regulations.gov by 
searching for and locating Docket No. FAA-2020-1005; 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 NPRM, the MCAI, 
any comments received, and other information. The street address for 
Docket Operations is listed above.

FOR FURTHER INFORMATION CONTACT: Deep Gaurav, Aviation Safety Engineer, 
New York ACO Branch, FAA, 1515 Stewart Avenue, Westbury, NY 11590; 
phone: (516) 228-7300; fax: (516) 794-5331; email: [email protected].

SUPPLEMENTARY INFORMATION:

Comments Invited

    The FAA invites you to send any written relevant data, views, or 
arguments about this proposal. Send your comments to an address listed 
under ADDRESSES. Include ``Docket No. FAA-2020-1005; Project Identifier 
MCAI-2020-00709-A'' at the beginning of your comments. The most helpful 
comments reference a specific portion of the proposal, explain the 
reason for any recommended change, and include supporting data. The FAA 
will consider all comments received by the closing date and may amend 
this proposal because of those comments.
    Except for Confidential Business Information (CBI) as described in 
the following paragraph, and other information as described in 14 CFR 
11.35, the FAA will post all comments received, without change, to 
https://www.regulations.gov, including any personal information you 
provide. The agency will also post a report summarizing each 
substantive verbal contact received about this NPRM.

Confidential Business Information

    CBI is commercial or financial information that is both customarily 
and actually treated as private by its owner. Under the Freedom of 
Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public 
disclosure. If your comments responsive to this NPRM contain commercial 
or financial information that is customarily treated as private, that 
you actually treat as private, and that is relevant or responsive to 
this NPRM, it is important that you clearly designate the submitted 
comments as CBI. Please mark each page of your submission containing 
CBI as ``PROPIN.'' The FAA will treat such marked submissions as 
confidential under the FOIA, and they will not be placed in the public 
docket of this NPRM. Submissions containing CBI should be sent to Deep 
Gaurav, Aviation Safety Engineer, New York ACO Branch, FAA, 1515 
Stewart Avenue, Westbury, NY 11590. Any commentary that the FAA 
receives which is not specifically designated as CBI will be placed in 
the public docket for this rulemaking

Background

    Transport Canada, which is the aviation authority for Canada, has 
issued Transport Canada AD CF-2020-20, dated May 27, 2020 (referred to 
after this as ``the MCAI''), to address an unsafe condition on Viking 
Air Limited (formerly Bombardier Inc.) Model DHC-3 airplanes. The MCAI 
states:

    A DHC-3 experienced an in-flight failure of a wing strut in 
October 2019. Inspection

[[Page 72199]]

of the failed part determined that it had fractured and that the 
fracture was consistent with fatigue damage. The investigation of 
the occurrence is ongoing.
    In 1969, it was determined from fatigue testing and analysis 
that part number (P/N) C3W100 wing strut assemblies on DHC-3 that 
were used for normal operations at a maximum weight of 8000 pounds 
should be removed from service before they have accumulated more 
than 20 000 hours air time. This information, including definitions 
of normal operations, was published in Service Bulletin 3/10 dated 
26 August 1969. It was also published at the same time in Appendix 4 
Part 6, Structural Component Recommended Service Life Limits, of the 
DHC-3 Maintenance Manual PSM 1-3-2.
    It is Transport Canada Civil Aviation (TCCA) policy to mandate 
compliance with new or more restrictive airworthiness limitations 
(AWLs) by the issuance of an AD if the AWL is established after 
products that are affected by the AWL are already in service. To 
date, TCCA has not mandated compliance with the 20 000 hours air 
time life limit AWL that is applicable to P/N C3W100 wing strut 
assemblies. This AD includes a requirement to comply with the life 
limit.
    Some DHC-3 aeroplanes have been modified to permit operations at 
maximum weights above 8000 pounds. For example, TCCA Supplemental 
Type Certificate (STC) SA95-32 increases the maximum operating 
weight to 8367 pounds. This STC includes a requirement to reduce the 
life limit that is applicable to P/N C3W100 wing strut assembly from 
20 000 hours air time to 17 500 hours air time, adjusted for the 
amount of time that the wing strut assembly is used at the higher 
maximum operating weight. Because this reduced life limit has been 
in place since the initial issue of STC SA95-32 in 1995, TCCA 
considers compliance to be mandatory for all aeroplanes that have 
been modified in accordance with the STC.
    In November 2019, Viking Air Ltd. (Viking) issued Alert Service 
Bulletin (ASB) V3/0011. The ASB provides instructions for a one-time 
inspection and follow-on corrective actions for all dash numbers of 
wing strut assembly P/N C3W100. Since that time, several operators 
have reported the results of the inspection to Viking. The 
information in the operators' reports suggests that other DHC-3 wing 
struts may be at risk of failure. The inspection of the wing struts 
on five aeroplanes revealed crack indications during non-destructive 
inspection of bolt holes, seized bolts, pitting corrosion and 
fretting on the face of lug plates, scratches and gouges in the bolt 
hole of a lug plate. Failure of a wing strut could result in a 
catastrophic in-flight breakup of the wing.
    This [Transport Canada] AD mandates the accomplishment of ASB 
V3/0011 or alternative inspection instructions provided by Viking on 
wing struts that have accumulated more than 2500 hours air time as 
of the effective date of this AD. New or serviceable struts 
installed on aeroplanes after the effective date of this AD that 
accumulate more than 2500 hours air time after the effective date of 
this AD are not subject to this AD or to the ASB V3/0011 
inspections.

    You may examine the MCAI in the AD docket at https://www.regulations.gov by searching for and locating Docket No. FAA-2020-
1005.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Viking DHC-3 Otter Alert Service Bulletin No. V3/
0011, Revision NC, dated November 26, 2019. The service information 
contains procedures for a bolt hole eddy current inspection of the lug 
hole on the lug plate part number (P/N) C3W104, a visual and 
fluorescent dye penetrant inspection of the lug fitting P/Ns C3W102 and 
C3W103, and a visual and eddy current surface scan inspection of the 
wing strut assembly P/N C3W101. 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.

FAA's Determination

    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 and 
service information referenced above. The FAA is issuing this NPRM 
after determining the unsafe condition described previously is likely 
to exist or develop on other products of the same type design.

Proposed AD Requirements in This NPRM

    This proposed AD would require accomplishing the actions specified 
in the service information already described.

Differences Between This Proposed AD and the MCAI

    The MCAI allows an alternative inspection, obtained from the design 
approval holder, if completed within 5 months. This proposed AD does 
not include this alternative; however, operators who choose this option 
may propose an alternative method of compliance in accordance with 
paragraph (h) of the proposed AD.

Interim Action

    The FAA considers this proposed AD interim action. The inspection 
reports that would be required by this AD will be used by Viking and 
Transport Canada to determine if there is a need for further action. If 
additional action is later identified, the FAA might consider further 
rulemaking.

Costs of Compliance

    The FAA estimates that this AD, if adopted as proposed, would 
affect 39 airplanes of U.S. registry. The FAA also estimates that it 
would take about 32 work-hours per airplane to comply with the 
inspection and repair or replacement requirements of this proposed AD. 
The proposed reporting requirement would take about 1 work-hour. The 
average labor rate is $85 per work-hour. Required parts would cost 
about $31,415 per airplane.
    Based on these figures, the FAA estimates the cost of the proposed 
AD on U.S. operators would be $1,334,580 or $34,220 per airplane.
    The FAA has included all known costs in its cost estimate. 
According to the manufacturer, however, some of the costs of this 
proposed AD may be covered under warranty, thereby reducing the cost 
impact on affected operators.

Paperwork Reduction Act

    A federal agency may not conduct or sponsor, and a person is not 
required to respond to, nor shall a person be subject to a penalty for 
failure to comply with a collection of information subject to the 
requirements of the Paperwork Reduction Act unless that collection of 
information displays a current valid OMB Control Number. The OMB 
Control Number for this information collection is 2120-0056. Public 
reporting for this collection of information is estimated to take 
approximately 1 hour per response, including the time for reviewing 
instructions, searching existing data sources, gathering and 
maintaining the data needed, and completing and reviewing the 
collection of information. All responses to this collection of 
information are mandatory. Send comments regarding this burden estimate 
or any other aspect of this collection of information, including 
suggestions for reducing this burden, to: Information Collection 
Clearance Officer, Federal Aviation Administration, 10101 Hillwood 
Parkway, Fort Worth, TX 76177-1524.

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

[[Page 72200]]

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

    The FAA 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) Would not affect intrastate aviation in Alaska, and
    (3) Would 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

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:

Viking Air Limited (Type Certificate Previously Held by Bombardier 
Inc.): Docket No. FAA-2020-1005; Project Identifier MCAI-2020-00709-
A.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by February 4, 2022.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Viking Air Limited (type certificate 
previously held by Bombardier Inc.) Model DHC-3 airplanes, all 
serial numbers, certificated in any category, with a wing strut 
assembly part number (P/N) C3W100 (all dash numbers) installed.

(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 identifies the unsafe condition as fatigue damage 
of the wing struts. The FAA is issuing this AD to prevent failure of 
a wing strut. The unsafe condition, if not addressed, could result 
in an in-flight breakup of the wing.

(f) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

(g) Required Actions

    (1) For airplanes that have not been modified with Supplemental 
Type Certificate (STC) SA00438NY: Before each wing strut assembly P/
N C3W100 accumulates 20,000 hours total time-in-service (TIS) or 
within 30 days after the effective date of this AD, whichever occurs 
later, remove the wing strut assembly P/N C3W100 from service and 
replace with a new (zero hours TIS) part. Thereafter, remove each 
wing strut assembly P/N C3W100 from service and replace with a new 
(zero hours TIS) part before accumulating 20,000 hours total TIS.
    (2) For airplanes with a wing strut assembly P/N C3W100 with 
more than 2,500 hours total TIS on the effective date of this AD, 
regardless of whether the airplane has been modified with STC 
SA00438NY: Within 30 days after the effective date of this AD, 
inspect the wing strut assembly and attachment hardware for cracks, 
corrosion, and damage in accordance with the Accomplishment 
Instructions in Viking DHC-3 Otter Alert Service Bulletin No. V3/
0011, Revision NC, dated November 26, 2019, except you are not 
required to contact Viking.
    (3) For all affected airplanes: Within 30 days after completing 
the inspection required by paragraph (g)(2) of this AD or within 30 
days after the effective date of this AD, whichever occurs later, 
report the results of the inspection to Viking using the inspection 
reply form in Viking DHC-3 Otter Alert Service Bulletin No. V3/0011, 
Revision NC, dated November 26, 2019.

(h) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, New York ACO Branch, FAA, has the authority to 
approve AMOCs 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 responsible Flight Standards Office, 
as appropriate. If sending information directly to the manager of 
the certification office, send it to the attention of the person 
identified in paragraph (i)(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.

(i) Related Information

    (1) For more information about this AD, contact Deep Gaurav, 
Aviation Safety Engineer, New York ACO Branch, FAA, 1515 Stewart 
Avenue, Westbury, NY 11590; phone: (516) 228-7300; fax: (516) 794-
5331; email: [email protected].
    (2) Refer to MCAI Transport Canada AD CF-2020-20, dated May 27, 
2020, for related information. You may examine the Transport Canada 
AD in the AD docket at https://www.regulations.gov by searching for 
and locating Docket No. FAA-2020-1005.
    (3) For service information identified in this AD, contact 
Viking Air Ltd., 1959 de Havilland Way, Sidney British Columbia, 
Canada V8L 5V5; phone: (800) 663-8444; email: 
[email protected]; website: https://www.vikingair.com. 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 (817) 222-5110.

    Issued on December 15, 2021.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2021-27509 Filed 12-20-21; 8:45 am]
BILLING CODE 4910-13-P


