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Proposed Rule

Airworthiness Directives; Viking Air Limited Model DHC-6 Series Airplanes

Document Details

Information about this document as published in the Federal Register.

Published Document

This document has been published in the Federal Register. Use the PDF linked in the document sidebar for the official electronic format.

Start Preamble

AGENCY:

Federal Aviation Administration (FAA), Department of Transportation (DOT).

ACTION:

Notice of proposed rulemaking (NPRM).

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:

Certain structural components must be replaced by new components at a certain stage of the aircraft's life to avoid any possibility of fatigue failure.

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 December 14, 2007.

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, U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590.

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.

Start Further Info

FOR FURTHER INFORMATION CONTACT:

George Duckett, Aerospace Engineer, FAA, New York Certification Office, 1600 Stewart Avenue, suite 410, Westbury, New York 11590; telephone: (516) 228-7325; fax: (516) 794-5531.

End Further Info End Preamble Start Supplemental Information

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-2007-27192; Directorate Identifier 2007-CE-008-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://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 February 4, 1983, we issued AD 83-02-02, Amendment 39-4553. That AD required actions intended to address an unsafe condition on the products listed above.

Since we issued AD 83-02-02, structural evaluations of the DHC-6 series airplanes have shown that the service life limits and inspection schedules need to be revised.

Transport Canada, which is the aviation authority for Canada, has issued AD No. CF-2000-14, dated May 25, 2000, (referred to after this as “the MCAI”), to correct an unsafe condition for the specified products. The MCAI refers to the Product Support Manual (PSM) 1-6-11, Revision 5, dated January 11, 2000, which describes the unsafe condition as:

Certain structural components must be replaced by new components at a certain stage of the aircraft's life to avoid any possibility of fatigue failure.

The MCAI requires you to inspect, modify, and/or retire affected structural components to maintain the structural integrity of DHC-6 airplanes.

You may obtain further information by examining the MCAI in the AD docket.

Relevant Service Information

Viking Air Limited has issued PSM 1-6-11, Revision 6, dated March 28, 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 Start Printed Page 64011of 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

Based on the service information, we estimate that this proposed AD would affect about 166 products of U.S. registry. We also estimate that it would take about 30 work-hours per product to comply with the basic requirements of this proposed AD. The average labor rate is $80 per work-hour. Required parts would cost about $988 per product.

Based on these figures, we estimate the cost of the proposed AD on U.S. operators to be $562,408, or $3,388 per product.

We have no way of determining the number of airplanes that may need any modifications, repairs, or replacements based on the results of the repetitive inspections.

In addition, since the proposed AD is reducing the life limit of certain structural components of the affected airplanes, there would be replacement costs incurred earlier than expected. The FAA has no way of determining the operational usage of each airplane. Therefore, we cannot determine what these costs would be.

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.

Start List of Subjects

List of Subjects in 14 CFR Part 39

End List of Subjects

The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows:

Start Part

PART 39—AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Start Authority

Authority: 49 U.S.C. 106(g), 40113, 44701.

End Authority
[Amended]

2. The FAA amends § 39.13 by removing AD 83-02-02, Amendment 39-4553; and adding the following new AD:

Viking Air Limited (formerly Bombardier Inc.): Docket No. FAA-2007-27192; Directorate Identifier 2007-CE-008-AD.

Comments Due Date

(a) We must receive comments by December 14, 2007.

Affected ADs

(b) This AD supersedes AD 83-02-02, Amendment 39-4553.

Applicability

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

Subject

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

Reason

(e) The mandatory continuing airworthiness information (MCAI) refers to the Product Support Manual (PSM) 1-6-11, Revision 5, dated January 11, 2000, which states:

Certain structural components must be replaced by new components at a certain stage of the aircraft's life to avoid any possibility of fatigue failure.

The MCAI requires you to inspect, modify, and/or retire affected structural components to maintain the structural integrity of DHC-6 airplanes.

Actions and Compliance

(f) Unless already done, within 30 days after the effective date of this AD, for all aircraft, incorporate the inspections, modifications, and/or retirement of components specified in Bombardier Inc. (formerly de Havilland) DHC-6 “Twin Otter” PSM 1-6-11, Revision 6, dated March 28, 2007, into the aircraft maintenance program. The compliance times are specified in the manual. For aircraft that are approaching or have exceeded the threshold of the new or revised inspections introduced by this AD, compliance with the threshold inspection may be modified as detailed below:

(1) Pre Mod 6/1117 Wing Assemblies:

(i) If the last inspection done of the main wing spar attachment lug fastener holes, before the effective date of this AD, was an eddy current inspection following Bombardier Inc. (formerly de Havilland) DHC-6 “Twin Otter” PSM 1-6-11, Revision 5, dated January 11, 2000; or PSM 1-6-11, Revision 6, dated March 28, 2007; do the repeat high frequency eddy current inspection in accordance with the schedule in PSM 1-6-11, Revision 6, dated March 28, 2007.

(ii) If the last inspection done of the main wing spar attachment lug fastener holes, before the effective date of this AD, was an ultrasonic inspection following Bombardier Service Bulletin 6/525, dated September 6, 1996, do the first high frequency eddy current inspection within 1,000 hours time-in-service (TIS) or 2,000 flights, whichever occurs first, after the last ultrasonic inspection. Repetitively inspect thereafter in accordance with the schedule in PSM 1-6-11, dated March 28, 2007.

(2) Post Mod 6/1117 and Post Mod 6/1630 Wing Assemblies: If the inspection threshold for the lower wing skin, stringers, and aft Start Printed Page 64012spar lower flange WS122 to WS263 (ribs 8 to 20) has been exceeded or will be exceeded within 6 months after the effective date of this AD, do the initial inspection within the next 500 hours TIS, 1,000 flights, or 6 months after the effective date of this AD, whichever occurs first, following PSM 1-6-11, Revision 6, dated March 28, 2007.

(g) You may take “unless already done” credit if the above actions were done following the procedures described in Bombardier Inc. (formerly de Havilland) DHC-6 “Twin Otter” PSM 1-6-11, Revision 5, dated January 11, 2000.

FAA AD Differences

Note:

This AD differs from the MCAI and/or service information as follows: The MCAI references PSM 1-6-11, Revision 5, dated January 11, 2000. PSM 1-6-11, Revision 6, dated March 28, 2007, has since been issued and is referenced for compliance in this AD.

Other FAA AD Provisions

(h) 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: George Duckett, Aerospace Engineer, Airframe and Propulsion Branch, FAA, New York Certification Office, 1600 Stewart Avenue, suite 410, Westbury, New York 11590; telephone: (516) 228-7325; 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

(i) Refer to MCAI Transport Canada AD No. CF-2000-14, dated May 25, 2000; and Viking Air Limited Structural Components Service Life Limits Manual PSM 1-6-11, Revision 6, dated March 28, 2007, for related information.

Start Signature

Issued in Kansas City, Missouri, on November 6, 2007.

David R. Showers,

Acting Manager, Small Airplane Directorate, Aircraft Certification Service.

End Signature End Part End Supplemental Information

[FR Doc. E7-22264 Filed 11-13-07; 8:45 am]

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