
[Federal Register: July 1, 2008 (Volume 73, Number 127)]
[Rules and Regulations]               
[Page 37355-37358]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr01jy08-2]                         

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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; 
Amendment 39-15574; AD 2008-13-11]
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: Final rule.

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SUMMARY: We are adopting a new airworthiness directive (AD) for the 
products listed above. This AD results from mandatory continuing 
airworthiness information (MCAI) issued 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. We are 
issuing this AD to require actions to correct the unsafe condition on 
these products.

DATES: This AD becomes effective August 5, 2008.
    On August 5, 2008, the Director of the Federal Register approved 
the incorporation by reference of certain publications listed in this 
AD.

ADDRESSES: You may examine the AD docket on the Internet at http://
www.regulations.gov or in person at Document Management Facility, 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: Richard Beckwith, Aerospace Engineer, 
FAA, New York Certification Office, 1600 Stewart Avenue, Suite 410, 
Westbury, New York 11590; telephone: (516) 228-7302; fax: (516) 568-
2716.

SUPPLEMENTARY INFORMATION: 

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 to include an AD that would apply to the specified products. 
That NPRM was published in the Federal Register on March 31, 2008 (73 
FR 16779). That NPRM proposed 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.

Comments

    We gave the public the opportunity to participate in developing 
this AD. We have considered the comment received.
    The Aircraft Owners and Pilots Association (AOPA) states that:

    AOPA opposes broad-based fleet-wide airworthiness directives to 
address corrosion related issues such as this one. Instead AOPA 
supports a more focused approach that takes aircraft maintenance and 
usage into account; instead of an AD based solely on age.

    In general, the FAA agrees that broad-based fleet-wide ADs are not 
always appropriate. However, in this case, the FAA has determined an AD 
should be issued because an unsafe condition exists in the product and 
the condition is likely to exist or develop in other products of the 
same type design.
    The FAA is issuing this AD for two reasons, both of which are 
stated in the NPRM. First, service experience indicates that as 
aircraft become older, they are more likely to exhibit indications of 
corrosion. Second, we have performed a review of the relevant service 
experience, including a review of the Corrosion Prevention and Control 
Program inspection reports that were made by operators to the 
manufacturer. This service experience supports the issuance of an AD.
    The FAA agrees in principle that based upon maintenance history, 
type of usage, etc., some operators may be in the position to address 
this unsafe condition using alternative methods to those proposed in 
the NPRM. However, it is not possible for the FAA to know all 
operators' specific conditions and write a different AD for each 
operator. Operators are encouraged to provide supporting evidence 
regarding their maintenance and operations in support of an alternative 
method of compliance (AMOC) when appropriate and should follow the 
procedures in 14 CFR 39.19 and this AD for requesting an AMOC.
    We are not changing the final rule AD action based on this comment.

Conclusion

    We reviewed the available data, including the comment received, and 
determined that air safety and the public interest require adopting the 
AD as proposed.

Differences Between This 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 assure 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 required 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 AD.

Costs of Compliance

    Based on the service information, we estimate that this AD will 
affect 162 products of U.S. registry. We also estimate that it will 
take about 40 work-hours per product to comply with basic requirements 
of this AD. The average labor rate is $80 per work-hour.
    Based on these figures, we estimate the cost of this AD to the 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:

[[Page 37356]]

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 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 this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866;
    (2) Is not a ``significant rule'' under 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.
    We prepared a regulatory evaluation of the estimated costs to 
comply with this AD and placed it in the AD Docket.

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 the NPRM, 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.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

0
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 AD:

2008-13-11 Viking Air Limited: Amendment 39-15574; Docket No. FAA-
2008-0367; Directorate Identifier 2007-CE-089-AD.

Effective Date

    (a) This airworthiness directive (AD) becomes effective August 
5, 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 August 5, 2008 (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, 
released and dated January 15, 2007 (individual pages dated as 
specified in the List of Effective Pages on pages 7 through 12 of 
the document); 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 number 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.
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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, 
released and dated January 15, 2007 (individual pages dated as 
specified in the List of Effective Pages on pages 7 through 12 of 
the document). 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 for
Applicable airplane serial numbers     all airplanes in applicable S/N
                                                    range
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(i) 001 through 199...............  15 months after August 5, 2008 (the
                                     effective date of this AD).
(ii) 200 through 439..............  27 months after August 5, 2008 (the
                                     effective date of this AD).
(iii) 440 through 659.............  51 months after August 5, 2008 (the
                                     effective date of this AD).
(iv) 660 through 844..............  63 months after August 5, 2008 (the
                                     effective date of this AD).
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[[Page 37357]]

    (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, released and 
dated January 15, 2007 (individual pages dated as specified in the 
List of Effective Pages on pages 7 through 12 of the document).
    (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 assure 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 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.

                              AD 2008-13-11
                            INSPECTION REPORT
               (REPORT ONLY IF YOU FIND LEVEL 3 CORROSION)
------------------------------------------------------------------------

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




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




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




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Send to:

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


Telephone: 250.656.7227
Fax: 250.656.9702
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                                Figure 1.



[[Page 37358]]

Related Information

    (h) Refer to MCAI Transport Canada AD No. CF-94-12R1, dated 
April 13, 1999; Transport Canada AD No. CF-99-11, dated May 28, 
1999; 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.

Material Incorporated by Reference

    (i) You must use the service information specified in Table 3--
Material Incorporated by Reference, of this AD to do the actions 
required by this AD, unless the AD specifies otherwise.
    (1) The Director of the Federal Register approved the 
incorporation by reference of this service information under 5 
U.S.C. 552(a) and 1 CFR part 51.
    (2) For service information identified in this AD, contact 
Viking Air Limited, VP Engineering, 9574 Hampden Road, Sidney, 
British Columbia, Canada V8L 5V5; Telephone: 250.656.7227; Fax: 
250.656.9702.
    (3) You may review copies at the FAA, Central Region, Office of 
the Regional Counsel, 901 Locust, Room 506, Kansas City, Missouri 
64106; or at the National Archives and Records Administration 
(NARA). For information on the availability of this material at 
NARA, call 202-741-6030, or go to: http://www.archives.gov/federal-
register/cfr/ibr-locations.html.

                                  Table 3.--Material Incorporated by Reference
----------------------------------------------------------------------------------------------------------------
         Service Bulletin No.                   Pages                   Revision                   Date
----------------------------------------------------------------------------------------------------------------
(i) DHC-6 Twin Otter (Series 100/200/  1 through 304..........  Revision 3.............  Released and dated
 300) Corrosion Prevention and                                                            January 15, 2007
 Control Manual PSM 1-6-5.                                                                (individual pages
                                                                                          dated as specified in
                                                                                          the List of Effective
                                                                                          Pages on pages 7
                                                                                          through 12 of the
                                                                                          document).
(ii) Viking Temporary Revision, C57-   1 through 3............  Temporary Revision No.:  December 19, 2007.
 10-18 (TR 2-2).                                                 2-2.
(iii) Viking Temporary Revision, Part  1 through 2............  Temporary Revision No.:  December 19, 2007.
 3, Supplement 1 (TR 3-2).                                       3-2.
(iv) Viking Temporary Revision, Part   1 through 2............  Temporary Revision No.:  December 19, 2007.
 3, Supplement 1 (TR 3-3).                                       3-3.
(v) Viking Temporary Revision, Part    1 through 2............  Temporary Revision No.:  December 19, 2007.
 3, Supplement 1, (TR 3-4).                                      3-4.
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    Issued in Kansas City, Missouri, on June 12, 2008.
Kim Smith,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. E8-13848 Filed 6-30-08; 8:45 am]

BILLING CODE 4910-13-P
