AD 2008-13-11

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: \n\n\tService experience indicates that as aircraft become older, they are more likely to exhibit indications of corrosion. \n\nAdditionally, 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.

Final rule.

2008-13-11 Viking Air Limited: Amendment 39-15574; Docket No. FAA- 2008-0367; Directorate Identifier 2007-CE-089-AD. \n\nEffective Date \n\n\t(a) This airworthiness directive (AD) becomes effective August 5, 2008. \n\nAffected ADs \n\n\t(b) None. \n\nApplicability \n\n\t(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. \n\nSubject \n\n\t(d) Air Transport Association of America (ATA) Code 51: Structures. \n\nReason \n\n\t(e) The mandatory continuing airworthiness information (MCAI) states: \n\n\tService 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. \n\nAdditionally, 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. \n\nActions and Compliance \n\n\t(f) Unless already done, do the following actions: \n\t(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. \n\t(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 PSM1-6-5, 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: \n\n\tTable 1.--Viking Temporary Revisions\n\n\n\nTemporary revision number and date \n\n(i) Viking Temporary Revision, C57-10-18 (TR 2-2), dated December 19, 2007. \n(ii) Viking Temporary Revision, Part 3, Supplement 1 (TR 3-2), dated December 19, 2007. \n(iii) Viking Temporary Revision, Part 3, Supplement 1 (TR 3-3), dated December 19, 2007. \n(iv) Viking Temporary Revision, Part 3, Supplement 1, (TR 3-4), dated December 19, 2007.\n \n\nDetermine 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 7through 12 of the document). The initial accomplishment deadlines are specified in Table 2--Initial Accomplishment Deadline, of this AD: \n\n\tTable 2.--Initial Accomplishment Deadline\n\n\nApplicable airplane serial numbers\nInitial accomplishment deadline for all airplanes in applicable S/N range \n(i) 001 through 199\n15 months after August 5, 2008 (the effective date of this AD). \n(ii) 200 through 439\n27 months after August 5, 2008 (the effective date of this AD). \n(iii) 440 through 659\n51 months after August 5, 2008 (the effective date of this AD). \n(iv) 660 through 844\n63 months after August 5, 2008 (the effective date of this AD). \n\n\t(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). \n\t(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). \n\t(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). \n\t(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. \n\t(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. \n\nFAA AD Differences \n\n\tNote: This AD differs from the MCAI and/or service information as follows:No differences. \n\nOther FAA AD Provisions \n\n\t(g) The following provisions also apply to this AD: \n\t(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. \n\t(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. \n\t(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. \n\n\n\t\nRelated Information \n\n\t(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. \n\nMaterial Incorporated by Reference \n\n\t(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. \n\t(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. \n\t(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. \n\t(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. \n\n\tTable 3.--Material Incorporated by Reference\n\n\nService Bulletin No. \nPages \nRevision \nDate \n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n(i) DHC-6 Twin Otter (Series \n100/200/300) Corrosion Prevention and Control Manual PSM 1-6-5 \n1 through 304 \nRevision 3 \nreleased anddated January 15, 2007 (individual pages dated as specified in the List of Effective Pages on pages 7 through 12 of the document) \n\n\n\n\n(ii) Viking Temporary Revision, \nC57-10-18 (TR 2-2) \n1 through 3 \nTemporary Revision No.: 2-2 \nDecember 19, 2007 \n\n\n\n\n(iii) Viking Temporary Revision, Part 3, Supplement 1 (TR 3-2) \n1 through 2 \nTemporary Revision No.: 3-2 \nDecember 19, 2007 \n\n\n\n\n(iv) Viking Temporary Revision, Part 3, Supplement 1 (TR 3-3) \n1 through 2 \nTemporary Revision No.: 3-3 \nDecember 19, 2007 \n\n\n\n\n(v) Viking Temporary Revision, Part 3, Supplement 1, (TR 3-4) \n1 through 2 \nTemporary Revision No.: 3-4 \nDecember 19, 2007

Discussion \n\n\tWe 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: \n\n\tService 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. \n\nComments \n\n\tWe gave the public the opportunity to participate in developing this AD. We have considered the comment received. \n\tThe Aircraft Owners and Pilots Association (AOPA) states that: \n\n\tAOPA 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. \n\n\tIn 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. \n\tThe 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. \n\tThe 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. \n\tWe are not changing the final rule AD action based on this comment. \n\nConclusion \n\n\tWe reviewed the available data, including the comment received, and determined that air safety and the public interest require adopting the AD as proposed. \n\nDifferences Between This AD and the MCAI or Service Information \n\n\tWe 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. \n\tWe 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. \n\nCosts of Compliance \n\n\tBased 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. \n\tBasedon these figures, we estimate the cost of this AD to the U.S. operators to be $518,400 or $3,200 per product. \n\nAuthority for This Rulemaking \n\n\tTitle 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. \n\n\tWe are issuing this rulemaking under the authority described in "Subtitle VII, Part A, Subpart III, Section 44701: \n\nGeneral 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. \n\nRegulatory Findings \n\n\tWe 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. \n\tFor the reasons discussed above, I certify this AD: \n\t(1) Is not a "significant regulatory action'' under Executive Order 12866; \n\t(2) Is not a "significant rule'' under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and \n\t(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. \n\tWe prepared a regulatory evaluation of the estimated costs to comply with this AD and placed it in the AD Docket. \n\nExamining the AD Docket \n\n\tYou may examine the AD docket on the Internet at http: // www.regulations.gov; or in person atthe 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. \n\nList of Subjects in 14 CFR Part 39 \n\n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. \n\nAdoption of the Amendment \n\nAccordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows: \n\nPART 39--AIRWORTHINESS DIRECTIVES \n\n1. The authority citation for part 39 continues to read as follows: \n\n\tAuthority: 49 U.S.C. 106(g), 40113, 44701. \n\nSec. 39.13 (Amended) \n\n2. The FAA amends Sec. 39.13 by adding the following new AD: