E8-6468. 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).

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: [phone].
• 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 docket contains this proposed AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Office (telephone [phone]) 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: [phone]; fax: [phone].

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.

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.

§ 39.13

[Amended]

2. The FAA amends § 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:

Temporary revision no. and date

(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

Applicable airplane serial numbers	Initial accomplishment deadline for all airplanes in applicable S/N range
(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: [phone]; fax: [phone]. 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.

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: [phone]
Fax: [phone]

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.