Document ID: FAA-2008-0367-0001
Agency: faa
Document Type: Rule
Title: Airworthiness Directives; Viking Air Limited Models DHC-6-1, DHC- 6-100, DHC-6-200, and DHC-6-300 Airplanes
Posted Date: 2008-03-31T04:00Z

[Federal Register: March 31, 2008 (Volume 73, Number 62)]
[Proposed Rules]
[Page 16779-16782]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr31mr08-22]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2008-0367; Directorate Identifier 2007-CE-089-AD]
RIN 2120-AA64

Airworthiness Directives; Viking Air Limited Models DHC-6-1, DHC-
6-100, DHC-6-200, and DHC-6-300 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 the
products listed above. 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:

    Service experience indicates that as aircraft become older, they
are more likely to exhibit indications of corrosion.

Additionally, the FAA has reviewed the service experience and finds
this action to be necessary based upon that service experience. The
proposed AD would require actions that are intended to address the
unsafe condition described in the MCAI.

DATES: We must receive comments on this proposed AD by April 30, 2008.

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.

[[Page 16780]]

Examining the AD Docket

    You may examine the AD docket on the Internet at http://
www.regulations.gov; or in person at the Docket Management Facility
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 the Docket Office (telephone (800) 647-5527) is in the
ADDRESSES section. Comments will be available in the AD docket shortly
after receipt.

FOR FURTHER INFORMATION CONTACT: Richard Beckwith, Aerospace Engineer,
FAA, New York Aircraft Certification Office,1600 Stewart Avenue, Suite
410, Westbury, New York 11590; telephone: (516) 228-7302; fax: (516)
568-2716.

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-2008-0367;
Directorate Identifier 2007-CE-089-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://
www.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 No. CF-94-12R1, dated April 13, 1999; and AD No. CF-99-11,
dated May 28, 1999 (referred to after this as ``the MCAI''), to correct
an unsafe condition for the specified products. The MCAI states:

    Service experience indicates that as aircraft become older, they
are more likely to exhibit indications of corrosion. Transport
Canada, in conjunction with other airworthiness authorities, has
committed itself to ensuring that additional maintenance programs
for older aircraft are developed and implemented to minimize and
control corrosive deterioration that could jeopardize airworthiness.
Bombardier Inc., as manufacturer of the DHC-6 aircraft, has
developed a Corrosion Prevention and Control Program which
identifies specific areas that must be inspected to ensure the
structural integrity of the DHC-6 fleet.

Additionally, the FAA has reviewed the service experience of the Viking
Air Limited Models DHC-6-1, DHC-6-100, DHC-6-200, and DHC-6-300
airplanes and finds this action to be necessary based upon that service
experience.
    The MCAI requires that you do the corrosion tasks required by the
corrosion prevention and control program. You may obtain further
information by examining the MCAI in the AD docket.

Relevant Service Information

    Viking Air Limited has issued DHC-6 Twin Otter (Series 100/200/300)
Corrosion Prevention and Control Manual PSM 1-6-5, Revision 3, dated
January 15, 2007; Viking Temporary Revision, C57-10-18 (TR 2-2), dated
December 19, 2007; Viking Temporary Revision, Part 3, Supplement 1 (TR
3-2), dated December 19, 2007; Viking Temporary Revision, Part 3,
Supplement 1 (TR 3-3), dated December 19, 2007; and Viking Temporary
Revision, Part 3, Supplement 1, (TR 3-4), dated December 19, 2007. The
actions described in this service information are intended to correct
the unsafe condition identified in the MCAI.

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 together with the fact that the
FAA has reviewed the service experience and finds this action to be
necessary based upon that service experience. 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.

Differences Between This Proposed AD and the MCAI or Service
Information

    We have reviewed the MCAI and related service information and, in
general, agree with their substance. But we might have found it
necessary to use different words from those in the MCAI to ensure the
AD is clear for U.S. operators and is enforceable. In making these
changes, we do not intend to differ substantively from the information
provided in the MCAI and related service information.
    We might also have proposed different actions in this AD from those
in the MCAI in order to follow FAA policies. Any such differences are
highlighted in a NOTE within the proposed AD.

Costs of Compliance

    We estimate that this proposed AD would affect about 162 products
of U.S. registry. We also estimate that it would take about 40 work-
hours per product to comply with the basic requirements of this
proposed AD. The average labor rate is $80 per work-hour.
    Based on these figures, we estimate the cost of the proposed AD on
U.S. operators to be $518,400, or $3,200 per product.

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.

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); 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.

[[Page 16781]]

    We prepared a regulatory evaluation of the estimated costs to
comply with this proposed AD and placed it in the AD docket.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, 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:

Viking Air Limited: Docket No. FAA-2008-0367; Directorate Identifier
2007-CE-089-AD.

Comments Due Date

    (a) We must receive comments by April 30, 2008.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Models DHC-6-1, DHC-6-100, DHC-6-200, and
DHC-6-300 airplanes, serial numbers (SNs) 001 through 844,
certificated in any category.

Subject

    (d) Air Transport Association of America (ATA) Code 51:
Structures.

Reason

    (e) The mandatory continuing airworthiness information (MCAI)
states:

    Service experience indicates that as aircraft become older, they
are more likely to exhibit indications of corrosion. Transport
Canada, in conjunction with other airworthiness authorities, has
committed itself to ensuring that additional maintenance programs
for older aircraft are developed and implemented to minimize and
control corrosive deterioration that could jeopardize airworthiness.
Bombardier Inc., as manufacturer of the DHC-6 aircraft, has
developed a Corrosion Prevention and Control Program which
identifies specific areas that must be inspected to ensure the
structural integrity of the DHC-6 fleet.

Additionally, the FAA has reviewed the service experience of the
Viking Air Limited Models DHC-6-1, DHC-6-100, DHC-6-200, and DHC-6-
300 airplanes and finds this action to be necessary based upon that
service experience. The MCAI requires that you do the corrosion
tasks (CTs) required by the corrosion prevention and control
program.

Actions and Compliance

    (f) Unless already done, do the following actions:
    (1) Within the next 90 days after the effective date of this AD,
develop a schedule for doing the initial and repeat CTs required in
paragraph (f)(2) and (f)(3) of this AD.
    (2) Initially, do all of the seven basic CTs defined at
paragraph 3.0 of Part 3 of DHC-6 Twin Otter (Series 100/200/300)
Corrosion Prevention and Control Manual PSM 1-6-5, Revision 3, dated
January 15, 2007; and the temporary revisions listed in Table 1,
Viking Temporary Revisions, of this AD:

                  Table 1.--Viking Temporary Revisions
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                     Temporary revision no. and date
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(i) Viking Temporary Revision, C57-10-18 (TR 2-2), dated December 19,
 2007.
(ii) Viking Temporary Revision, Part 3, Supplement 1 (TR 3-2), dated
 December 19, 2007.
(iii) Viking Temporary Revision, Part 3, Supplement 1 (TR 3-3), dated
 December 19, 2007.
(iv) Viking Temporary Revision, Part 3, Supplement 1, (TR 3-4), dated
 December 19, 2007.
------------------------------------------------------------------------

Determine corrosion level following the definitions contained in the
introduction section of DHC-6 Twin Otter (Series 100/200/300)
Corrosion Prevention and Control Manual PSM 1-6-5, Revision 3, dated
January 15, 2007. The initial accomplishment deadlines are specified
in Table 2, Initial Accomplishment Deadline, of this AD:

                Table 2.--Initial Accomplishment Deadline
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                                         Initial accomplishment deadline
   Applicable airplane serial numbers    for all airplanes in applicable
                                                    S/N range
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(i) 001 through 199....................  15 months after the effective
                                          date of this AD.
(ii) 200 through 439...................  27 months after the effective
                                          date of this AD.
(iii) 440 through 659..................  51 months after the effective
                                          date of this AD.
(iv) 660 through 844...................  63 months after the effective
                                          date of this AD.
------------------------------------------------------------------------

    (3) After the initial completion of each CT, repeat each CT at
the repeat interval (R) specified in the manual. Determine corrosion
level following the definitions contained in the introduction
section of DHC-6 Twin Otter (Series 100/200/300) Corrosion
Prevention and Control Manual PSM 1-6-5, Revision 3, dated January
15, 2007.
    (4) If any corrosion is found during any action required by this
AD, before further flight, address corrosion following paragraph 4.0
of Part 3 of DHC-6 Twin Otter (Series 100/200/300) Corrosion
Prevention and Control Manual PSM 1-6-5, Revision 3, dated January
15, 2007. All repairs are to be done following a method approved by
the Manager, New York Aircraft Certification Office or Transport
Canada Civil Aviation (or its delegated agent).
    (5) Within 21 days after the finding of Level 3 corrosion,
submit a plan to the FAA to identify a schedule for accomplishing
the applicable CTs on the remainder of the airplanes in the
operator's fleet that are subject to this AD or data substantiating
that the Level 3 corrosion that was found is an isolated case. The
FAA may impose a schedule other than proposed in the plan upon
finding that a change to the schedule is needed to ensure that any
other Level 3 corrosion is detected in a timely manner. For the
purposes of this paragraph, the FAA is defined as the cognizant
principal maintenance inspector (PMI) for operators that are
assigned a PMI (e.g., part 121, 125, and 135 operators) and the
cognizant flight standards district office for other operators
(e.g., part 91 operators).
    (6) If any Level 3 corrosion is found while doing any action
required by this AD, within 21 days after the finding of Level 3
corrosion, report the finding on the form in Figure 1 of this AD and
send it to Viking Air Limited, VP Engineering, 9574 Hampden Road,
Sidney, British Columbia, Canada V8L 5V5.
    (7) Incorporation of the initial and repeat CTs into your FAA-
approved maintenance program constitutes terminating action for this
AD. If this AD is terminated in this way, then the maintenance
program must be in accordance with this AD.

FAA AD Differences

    Note: This AD differs from the MCAI and/or service information
as follows: No differences.

Other FAA AD Provisions

    (g) The following provisions also apply to this AD:
    (1) Alternative Methods of Compliance (AMOCs): The Manager, New
York Aircraft Certification Office (ACO), FAA, has the authority to
approve AMOCs for this AD, if requested using the procedures found
in 14 CFR 39.19. Send information to ATTN: Richard Beckwith,
Aerospace Engineer, FAA, New York ACO, 1600 Stewart Avenue, Suite
410, Westbury, New York 11590; telephone: (516) 228-7302; fax: (516)
568-2716. Before using any approved AMOC on any airplane to which
the AMOC applies, notify your

[[Page 16782]]

appropriate PMI in the FAA Flight Standards District Office (FSDO),
or lacking a PMI, your local FSDO.
    (2) Airworthy Product: For any requirement in this AD to obtain
corrective actions from a manufacturer or other source, use these
actions if they are FAA-approved. Corrective actions are considered
FAA-approved if they are approved by the State of Design Authority
(or their delegated agent). You are required to assure the product
is airworthy before it is returned to service.
    (3) Reporting Requirements: For any reporting requirement in
this AD, under the provisions of the Paperwork Reduction Act (44
U.S.C. 3501 et seq.), the Office of Management and Budget (OMB) has
approved the information collection requirements and has assigned
OMB Control Number 2120-0056.

                        Docket No. FAA-2008-0367
                            Inspection Report
               [Report only if you find level 3 corrosion]
------------------------------------------------------------------------

------------------------------------------------------------------------
1. Operator:                                2. Telephone:
------------------------------------------------------------------------
3. Airplane Model Number:                   4. Airplane Serial Number:
------------------------------------------------------------------------
5. Airplane Tail Number:                    6. Date of Inspection:
------------------------------------------------------------------------
7. Corrosion Task:

------------------------------------------------------------------------
8. Description & Specific Location of Findings:

------------------------------------------------------------------------
9. Additional Comments of Owner/Operator:

------------------------------------------------------------------------
Send to:

Viking Air Limited
VP Engineering
9574 Hampden Road
Sidney, British Columbia, Canada
V8L 5V5

Telephone: 250.656.7227
Fax: 250.656.9702

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

                                Figure 1.

Related Information

    (h) Refer to MCAI Transport Canada AD No. CF-94-12R1, dated
April 13, 1999; and Transport Canada AD No. CF-99-11, dated May 28,
1999; and DHC-6 Twin Otter (Series 100/200/300) Corrosion Prevention
and Control Manual PSM 1-6-5, Revision 3, dated January 15, 2007;
and the temporary revisions listed in Table 1--Viking Temporary
Revisions, of this AD, for related information.

David R. Showers,
Acting Manager, Small Airplane Directorate, Aircraft Certification
Service.
[FR Doc. E8-6468 Filed 3-28-08; 8:45 am]

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