[Federal Register Volume 87, Number 29 (Friday, February 11, 2022)]
[Proposed Rules]
[Pages 7965-7968]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-02888]


 ========================================================================
 Proposed Rules
                                                 Federal Register
 ________________________________________________________________________
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 This section of the FEDERAL REGISTER contains notices to the public of 
 the proposed issuance of rules and regulations. The purpose of these 
 notices is to give interested persons an opportunity to participate in 
 the rule making prior to the adoption of the final rules.
 
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  Federal Register / Vol. 87, No. 29 / Friday, February 11, 2022 / 
Proposed Rules  

[[Page 7965]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2022-0099; Project Identifier 2019-CE-019-AD]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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

SUMMARY: The FAA proposes to supersede Airworthiness Directive (AD) AD 
89-24-06 R1, which applies to all Boeing of Canada, Ltd. and de 
Havilland (now Viking Air Limited) Model DHC-6-1, DHC-6-100, DHC-6-200, 
and DHC-6-300 airplanes. This AD requires repetitively inspecting the 
elevator quadrant for damage and taking corrective action as necessary. 
Since the FAA issued AD 89-24-06 R1, the aviation authority for Canada 
revised its mandatory continuing airworthiness information (MCAI) to 
correct this unsafe condition on these products. The MCAI identifies 
the unsafe condition as damage to the flight control system. This 
proposed AD would retain the actions of AD 89-24-06 R1, extend the 
compliance time intervals for the repetitive inspections, add the Model 
DHC-6-400 airplane to the applicability, and add a fluorescent 
penetrant inspection requirement. 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 March 28, 
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-2022-0099; 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: Darren Gassetto, Aviation Safety 
Engineer, FAA, New York ACO Branch, 1600 Stewart Avenue, Suite 410, 
Westbury, NY 11590; phone: (516) 228-7323; 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-2022-0099; Project Identifier 
2019-CE-019-AD'' 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 
the 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 proposed AD.

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 
Darren Gassetto, Aviation Safety Engineer, FAA, New York ACO Branch, 
1600 Stewart Avenue, Suite 410, 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

    The FAA issued AD 89-24-06 R1, Amendment 39-6670 (55 FR 29347, July 
19, 1990) (AD 89-24-06 R1) for all Boeing of Canada, Ltd. and de 
Havilland (type certificate currently held by Viking Air Limited) Model 
DHC-6-1, DHC-6-100, DHC-6-200, and DHC-6-300 airplanes. AD 89-24-06 R1 
requires repetitively inspecting the elevator quadrant, P/N C6CFM 1138-
27 (Pre Mod 6/1394), P/N C6CFM 1450-27 (Post Mod 6/1394 or production 
cut-in (PCI) S/N 331, Pre Mod 6/1678), or P/N C6CFM 1450-29 (Post Mod 
6/1678 or PCI S/N 602), for distortion (warping, buckling, and score 
marks on the quadrant topside face caused by rubbing against the side 
of the cable guard) and

[[Page 7966]]

replacing if distortion is found. AD 89-24-06 R1 also requires 
inspecting the elevator quadrant mounting support bracket, P/N C6CFM 
1142-1, for cracks if distortion in the elevator quadrant is found and 
replacing any cracked P/N C6CFM 1142-1.

Actions Since AD 89-24-06 R1 Was Issued

    Since the FAA issued AD 89-24-06 R1, the type certificate holder 
for Model DHC-6-1, DHC-6-100, DHC-6-200, and DHC-6-300 airplanes 
changed from de Havilland to Viking Air Limited. In 2012, the FAA 
issued Viking Air Limited a type certificate for the Model DHC-6-400 
airplane as part of the DHC-6 series.
    Transport Canada, which is the aviation authority for Canada, 
superseded its prior ADs on this unsafe condition and issued Canadian 
AD CF-1972-06R5, dated June 22, 2018 (referred to after this as ``the 
MCAI''), to require a fluorescent penetrant inspection and expand the 
model applicability to include the Viking Air Limited Model DHC-6-400 
airplane. The MCAI states:

    Damage to the flight control system of DHC-6 aeroplanes was 
found during inspection. The damage has been attributed to ground 
gusts. The damage included cracks in the base of the lower control 
column, cracks and buckles in the elevator/rudder pulley bracket, 
and distortion of the elevator quadrant. Damage to the elevator 
quadrant may produce abnormal loads on the quadrant support bracket 
that damage the bracket.
    Damaged flight control components may fail when subjected to 
service loads, resulting in loss of control of the aeroplane.
    This revision of the [Transport Canada] AD clarifies the 
applicability of the corrective actions and endorses Service 
Bulletin (SB) 6/511 as a means of accomplishing some of the required 
inspections. In corrective action Part III, dye penetrant inspection 
has been replaced by fluorescent penetrant inspection.
    You may examine the MCAI in the AD docket at https://www.regulations.gov by searching for and locating Docket No. FAA-
2022-0099.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed DHC-6 (Twin Otter) Service Bulletin 6-511, 
Revision A, dated June 22, 1990. This service bulletin specifies 
procedures for repetitively inspecting the elevator quadrant for 
distortion (warping, buckling, and score marks), performing a one-time 
dye penetrant inspection of the elevator quadrant support bracket for 
cracks, and taking corrective actions. 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.

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 retain the actions of AD 89-24-06 R1, extend 
the compliance time intervals for the repetitive inspections, add the 
Model DHC-6-400 airplane to the applicability, and add a fluorescent 
penetrant inspection requirement with credit for the visual inspections 
done before the effective date of this proposed AD.

Differences Between This Proposed AD and the MCAI

    The MCAI addresses actions on the the control column lower 
assembly, the elevator pulley bracket system, and the elevator 
quadrant. This proposed AD would only require actions on the elevator 
quadrant and elevator quadrant support bracket. The FAA is not 
proposing to require the repetitive inspections of the control column 
lower sub-assembly, lower horizontal torque tube, and top and bottom 
channels of the pulley bracket assembly, and the modifications that 
terminate those inspections, because those actions are addressed by AD 
69-05-01 R2, Amendment 39-3824 (45 FR 45258, July 3, 1980) and AD 69-
08-12 R1, Amendment 39-867 (34 FR 18226, November 14, 1969).
    The MCAI applies to Viking Air Limited Model DHC-6 series 110, DHC-
6 series 210, DHC-6 series 310, and DHC-6 series 320, and this proposed 
AD would not because these models do not have an FAA type certificate. 
Transport Canada Model DHC-6 series 1, DHC-6 series 100, DHC-6 series 
200, DHC-6 series 300, and DHC-6 series 400 airplanes correspond to FAA 
Model DHC-6-1, DHC-6-100, DHC-6-200, DHC-6-300, and DHC-6-400 
airplanes, respectively.

Costs of Compliance

    The FAA estimates that this AD, if adopted as proposed, would 
affect 133 airplanes of U.S. registry.
    The FAA estimates the following costs to comply with this proposed 
AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                 Cost on U.S.
              Action                    Labor cost        Parts cost     Cost per airplane        operators
----------------------------------------------------------------------------------------------------------------
Elevator quadrant and support      .5 work-hour x $85              N/A  $42.50 per           $5,652.50 (for the
 bracket visual inspection.         per hour = $42.50.                   inspection cycle.    affected 133
                                                                                              airplanes) per
                                                                                              inspection cycle.
Fluorescent penetrant inspection   1 work-hour x $85               N/A  $85................  $10,795 (for the
 of the elevator quadrant support   per hour = $85.                                           affected 127
 bracket.                                                                                     airplanes).
----------------------------------------------------------------------------------------------------------------

    The FAA estimates the following costs to do any repairs or 
replacements that would be required based on the results of the 
proposed inspections. The FAA has no way of determining the number of 
airplanes that might need these repairs/replacements:

[[Page 7967]]



                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                     Cost per
                    Action                                 Labor cost               Parts cost       airplane
----------------------------------------------------------------------------------------------------------------
Replacement of elevator quadrant..............  1.5 work-hours x $85 per hour =             $825         $952.50
                                                 $127.50.
Fluorescent penetrant inspection of the         1 work-hour x $85 per hour = $85             N/A              85
 elevator quadrant support bracket.
Replacement of elevator quadrant support        2 work-hours x $85 per hour =                485             655
 bracket.                                        $170.
----------------------------------------------------------------------------------------------------------------

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

    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 that the 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:
0
a. Removing Airworthiness Directive 89-24-06 R1, Amendment 39-6670 (55 
FR 29347, July 19, 1990); and
0
b. Adding the following new airworthiness directive:

Viking Air Limited (Type Certificate previously held by Bombardier 
Inc., de Havilland, Inc.): Docket No. FAA-2022-0099; Project 
Identifier 2019-CE-019-AD.

 (a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by March 28, 2022.

(b) Affected ADs

    This AD replaces Airworthiness Directive (AD) 89-24-06 R1, 
Amendment 39-6670 (55 FR 29347, July 19, 1990) (AD 89-24-06 R1).

(c) Applicability

    This AD applies to Viking Air Limited (type certificate 
previously held by Bombardier Inc. and de Havilland, Inc.) Model 
DHC-6-1, DHC-6-100, DHC-6-200, DHC-6-300, and DHC-6-400 airplanes, 
all serial numbers, certificated in any category.

 (d) Subject

    Joint Aircraft System Component (JASC) Code 2700, Flight Control 
System.

(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 damage to the 
flight control system. The FAA is issuing this AD to prevent failure 
of the flight control system. The unsafe condition, if not 
addressed, could result in loss of control of the airplane.

(f) Compliance

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

(g) Elevator Quadrant and Support Brackets: Inspections, Replacements, 
and Modifications

    (1) Visually inspect the elevator quadrant for indications of 
distortion (warping, buckling, or score marks) by following 
paragraphs III.A.2.(a) and III.A.2.(b) of the Accomplishment 
Instructions in DHC-6 (Twin Otter) Service Bulletin 6-511, Revision 
A, dated June 22, 1990 (DHC-6 SB 6-511, Revision A) at the following 
applicable compliance times:
    (i) For Model DHC-6-1, DHC-6-100, DHC-6-200, and DHC-6-300 
airplanes, before further flight after the effective date of this AD 
or within 400 hours time-in-service (TIS) after the last inspection 
required by AD 89-24-06 R1, whichever occurs later, and thereafter 
at intervals not to exceed 400 hours TIS; or
    (ii) For Model DHC-6-400 airplanes, before further flight after 
the effective date of this AD and thereafter at intervals not to 
exceed 400 hours TIS.
    Note 1 to paragraph (g)(1): The elevator quadrant may be 
identified as P/N C6CFM1138-27 (Pre Mod 6/1394), P/N C6CFM1450-27 
(Post Mod 6/1394 or production cut-in (PCI) S/N 331, Pre Mod 6/
1678), or P/N C6CFM1450-29 (Post Mod 6/1678 or PCI S/N 602), and is 
referred to as assembly P/N C6CF1137-1, -3, -5, or -7.
    (2) If any indication of distortion is found on the elevator 
quadrant during any inspection required by paragraph (g)(1) of this 
AD, before further flight, replace the elevator quadrant with a 
serviceable part and inspect the elevator quadrant support bracket 
assembly for cracks by following paragraphs III.B.1. through 
III.B.4.(b) of the Accomplishment Instructions in DHC-6 SB 6-511, 
Revision A. This AD requires that you do a fluorescent penetrant 
inspection as the type of required dye penetrant inspection. If a 
crack is found in the elevator quadrant support bracket, before 
further flight, replace with a serviceable part by following 
paragraphs III.B.5 through III.B.12 of the Accomplishment 
Instructions in DHC-6 SB 6-511, Revision A.
    (3) For Model DHC-6-1, DHC-6-100, DHC-6-200, and DHC-6-300 
airplanes: Within 400 hours TIS after the effective date of this AD, 
unless already done within the preceding 12 months before the 
effective date of this AD, inspect the elevator quadrant support 
bracket assembly for cracks by

[[Page 7968]]

following paragraphs III.B.1. through III.B.4.(b) of the 
Accomplishment Instructions in DHC-6 SB 6-511, Revision A. This AD 
requires that you do a fluorescent penetrant inspection as the type 
of required dye penetrant inspection. If a crack is found in the 
elevator quadrant support bracket, before further flight, replace 
with a serviceable part by following paragraphs III.B.5 through 
III.B.12 of the Accomplishment Instructions in DHC-6 SB 6-511, 
Revision A.

(h) Credit for Previous Actions

    (1) For Model DHC-6-1, DHC-6-100, DHC-6-200, and DHC-6-300 
airplanes: This paragraph provides credit for the inspection 
required by paragraph (g)(1) of this AD if you performed the 
inspection before the effective date of this AD using paragraph 
(a)(1) of AD 89-24-06 R1.
    (2) For Model DHC-6-1, DHC-6-100, DHC-6-200, and DHC-6-300 
airplanes: This paragraph provides credit for the fluorescent 
penetrant inspection and subsequent replacement of the elevator 
quadrant support bracket due to a crack found from the fluorescent 
penetrant inspection required by paragraph (g)(2) of this AD if 
performed before the effective date of this AD using paragraphs 
(a)(3) and (4) of AD 89-24-06 R1.

 (i) 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 local Flight Standards District 
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 (j)(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.

(j) Related Information

    (1) For more information about this AD, contact Darren Gassetto, 
Aviation Safety Engineer, FAA, New York ACO Branch, 1600 Stewart 
Avenue, Suite 410, Westbury, NY 11590; phone: (516) 228-7323; email: 
[email protected].
    (2) Refer to Transport Canada AD Number CF-1972-06R5, dated June 
22, 2018, for more 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-2022-0099.
    (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.

    Dated: Issued on February 4, 2022.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2022-02888 Filed 2-10-22; 8:45 am]
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