[Federal Register: December 3, 2008 (Volume 73, Number 233)]
[Proposed Rules]
[Page 73618-73620]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr03de08-14]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2008-1267; Directorate Identifier 2008-CE-069-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 that would supersede an existing AD. 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:
There have been reports of inter-rivet cracking on several wing
front spar adapter assemblies (P/N C6WM1027-1) on the horizontal and
vertical flanges. It was determined that the cracking was caused by
stress corrosion in the short transverse grain initiated by local
riveting induced stresses.
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 January 2, 2009.
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.
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
[[Page 73619]]
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: Pong Lee, Aerospace Engineer, FAA, New
York Aircraft Certification Office, ANE-171, 1600 Stewart Avenue, Suite
410, Westbury, New York 11590; telephone: (516) 228-7324; fax: (516)
794-5531.
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-2008-1267;
Directorate Identifier 2008-CE-069-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
On May 15, 2008, we issued AD 2008-11-10, Amendment 39-15532 (73 FR
37353; July 1, 2008). That AD required actions intended to address an
unsafe condition on the products listed above.
Since we issued AD 2008-11-10, a complete list of affected part
numbers has been issued.
Relevant Service Information
Viking Air Limited has issued Viking DHC-6 Twin Otter Service
Bulletins No. V6/540, dated October 1, 2007; No. V6/541, dated October
1, 2007; and No. V6/542, dated October 1, 2007; and R.W. Martin, Inc.
Service Bulletin No. 00160/2, Revision A, dated November 15, 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. 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 AD will affect 157 products of U.S. registry.
We also estimate that it will take about 18 work-hours per product to
comply with the 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 on U.S.
operators to be $226,080 or $1,440 per product.
In addition, we estimate that any necessary follow-on actions will
take about 200 work-hours and require parts costing $3,696 for a cost
of $19,696 per product. We have no way of determining the number of
products that may need these actions.
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.
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, 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
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 removing Amendment 39-15532 (73 FR
37353; July 1, 2008), and adding the following new AD:
Viking Air Limited: Docket No. FAA-2008-1267; Directorate Identifier
2008-CE-069-AD.
Comments Due Date
(a) We must receive comments by January 2, 2009.
Affected ADs
(b) This AD supersedes AD 2008-11-10, Amendment 39-15532 (73 FR
37353; July 1, 2008).
[[Page 73620]]
Applicability
(c) This AD applies to the following Models DHC-6-1, DHC-6-100,
DHC-6-200, and DHC-6-300 airplanes, all serial numbers, that are
certificated in any category:
(1) Group 1: Equipped with wing boxes, part numbers (P/Ns)
C6W1002-1, C6W1002-3, WR6-1002-59 or WR6-1002-61 that incorporate a
P/N C6WM1027-1 front spar adapter assembly with 10 or more years of
service; and
(2) Group 2: Equipped with wing boxes, P/Ns C6W1002-5, C6W1002-
7, C6W1002-9, C6W1002-11, C6W1002-13, C6W1002-15, C6W1002-17,
C6W1002-19, C6W1002-21, C6W1002-23, C6W1002-51, C6W1002-53, C6W1002-
55, C6W1002-57 and C6W1002-61 that incorporate a P/N C6WM1027-1
front spar adapter assembly with 10 or more years of service.
Subject
(d) Air Transport Association of America (ATA) Code 57: Wings.
Reason
(e) The mandatory continuing airworthiness information (MCAI)
states:
There have been reports of inter-rivet cracking on several wing
front spar adapter assemblies (P/N C6WM1027-1) on the horizontal and
vertical flanges. It was determined that the cracking was caused by
stress corrosion in the short transverse grain initiated by local
riveting induced stresses. This directive mandates modification and
inspection of the wing front spar adapter fitting and replacement of
cracked fittings.
Actions and Compliance
(f) Unless already done, do the following actions:
(1) For Group 1 airplanes, within the next 180 days after August
5, 2008 (the effective date of AD 2008-11-10), install inspection
holes in the left-hand (LH) and right-hand (RH) lower wing skins
following Viking DHC-6 Twin Otter Service Bulletin Number V6/541,
dated October 1, 2007.
(2) For Group 2 airplanes, within the next 180 days after the
effective date of this AD, install inspection holes in the LH and RH
lower wing skins following Viking DHC-6 Twin Otter Service Bulletin
Number V6/541, dated October 1, 2007.
(3) For Group 1 and Group 2 airplanes, before further flight
after installing the inspection holes required in paragraph (f)(1)
or (f)(2) of this AD, initially inspect the LH and RH front spar
adapter assemblies for cracks, and repetitively thereafter inspect
all affected wing box P/Ns at intervals not to exceed 1,200 hours
time-in-service or 12 months, whichever occurs first, until the
replacement required in paragraph (f)(4) of this AD is done.
(i) For wing box P/Ns C6W1002-1, C6W1002-3, C6W1002-5, C6W1002-
7, C6W1002-9, C6W1002-11, C6W1002-13, C6W1002-15, C6W1002-17,
C6W1002-19, C6W1002-21, C6W1002-23, C6W1002-51, C6W1002-53, C6W1002-
55, C6W1002-57, C6W1002-59, and C6W1002-61, inspect following Viking
DHC-6 Twin Otter Service Bulletin Number V6/540, dated October 1,
2007.
(ii) For wing box P/Ns WR6-1002-59 or WR6-1002-61, inspect
following R.W. Martin, Inc. Service Bulletin No. 00160/2, Revision
A, dated November 15, 2007.
(4) For Group 1 and 2 airplanes, before further flight after
doing any inspection required in paragraph (f)(3) of this AD where
cracks are found, replace the cracked front spar adapter assembly
with a front spar adapter assembly, P/N C6WM1027-3. Do the
replacement following Viking DHC-6 Twin Otter Service Bulletin
Number V6/542, dated October 1, 2007. This replacement terminates
the repetitive inspections required in paragraph (f)(3) of this AD
for the replaced front spar adapter assembly.
(5) As a terminating action for the repetitive inspections
required in paragraph (f)(3) of this AD, at any time after the
initial inspection required in paragraph (f)(3) of this AD, you may
replace P/N C6WM1027-1 with P/N C6WM1027-3, except it must be
replaced prior to further flight as required by paragraph (f)(4) of
this AD.
FAA AD Differences
Note: This AD differs from the MCAI and/or service information
as follows: MCAI Transport Canada AD No. CF-2007-31, dated December
17, 2007, is applicable to airplane models with front spar adapter
assembly P/N C6WM1027-3 that incorporate task C57-10-18 of the DHC-6
Corrosion Prevention and Control Manual (CPCM), PSM 1-6-5. The
applicability of this proposed AD does not include airplane models
with front spar adapter assembly P/N C6WM1027-3 that incorporate
task C57-10-18 of the DHC-6 CPCM, PSM 1-6-5, which is required in
the Transport Canada ADs No. CF-94-12R1, dated April 13, 1999, and
AD No. CF-99-11, dated May 28, 1999. We have addressed the Corrosion
Prevention and Control Program in AD 2008-13-11 (73 FR 37355, July
1, 2008), which identifies specific areas that must be inspected to
ensure the structural integrity of the DHC-6 fleet.
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, 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: Pong Lee, Aerospace
Engineer, FAA, New York Aircraft Certification Office, ANE-171, 1600
Stewart Avenue, Suite 410, Westbury, New York 11590; telephone:
(516) 228-7324; fax: (516) 794-5531. Before using any approved AMOC
on any airplane to which the AMOC applies, notify your appropriate
principal inspector (PI) in the FAA Flight Standards District Office
(FSDO), or lacking a PI, 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.
Related Information
(h) Refer to MCAI Transport Canada AD No. CF-2007-31, dated
December 17, 2007; Viking DHC-6 Twin Otter Service Bulletins No. V6/
540, dated October 1, 2007; No. V6/541, dated October 1, 2007; and
No. V6/542, dated October 1, 2007; and R.W. Martin, Inc. Service
Bulletin No. 00160/2, Revision A, dated November 15, 2007, for
related information.
Issued in Kansas City, Missouri, on November 26, 2008.
Kim Smith,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. E8-28645 Filed 12-2-08; 8:45 am]
BILLING CODE 4910-13-P