Discussion
What events have caused this AD? Transport Canada, which is the airworthiness authority for Canada, notified FAA that an unsafe condition may exist on all Bombardier Inc. Model (Otter) DHC-3 airplanes that incorporate 524085 BC, Ltd. STC Number ST01243NY or SA01243NY. Transport Canada reports one incident of structural failure of the elevator servo tab balance assembly.
What is the potential impact if FAA took no action? Vibration may cause structural failure of the elevator servo tab. This failure could lead to loss of control of the airplane.
Has FAA taken any action to this point? We issued a proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an AD that would apply to Bombardier Inc. Model (Otter) DHC-3 airplanes that incorporate 524085 BC, Ltd. STC Number ST01243NY or SA01243NY. This proposal was published in the Federal Register as a notice of proposed rulemaking (NPRM) on July 29, 2004(69 FR 45293-95). The NPRM proposed to replace the existing Viking Air Ltd. elevator servo tab assembly with a redesigned Viking Air Ltd. elevator servo tab assembly.
Comments
Was the public invited to comment? We provided the public the opportunity to participate in developing this AD. The following presents the comments received on the proposal and FAA's response to each comment:
Comment Issue: Question as to Whether Viking Air Is Authorized for Replacement Parts
What is the commenter's concern? The commenter wants the issuance of the Airworthiness Directive to be delayed until it is determined whether the manufacture of the parts is authorized through a Canadian Parts Design Approval (PDA), a Canadian Approval Limitation Record (ALR), or 14 CFR 21.303(a). The commenter claims that the manufacturing of these parts should be authorized through a Canadian PDA, not an ALR, and that Viking Air is not authorized to manufacture the parts per 14 CFR 21.303(a).
What is FAA's response to the concern? The FAA does not agree. Viking Air manufactured the parts that are being removed per the AD for STC SA01243NY under a Canadian ALR. The modification parts being installed per the AD following Viking Air Service Bulletin V3/01 are the same parts as in the latest amendment to STC SA01243NY. Viking Air, under the Canadian ALR, 22-80 manufactured the parts for STC SA01243NY for export to the United States with Transport Canada Civil Aviation (TCCA) Export Certificates of Airworthiness. Per the Implementation Procedures Agreement (IPA) of the U.S./Canadian Bilateral Aviation Safety Agreement (BASA), the FAA accepts TCCA Export Certificates of Airworthiness for replacement and modification parts. Civil Airworthiness Regulations (CAR)/Airworthiness Manual Chapter 561 covers the manufacturing of replacement and modification parts. Regulation 14 CFR 21.303 "Replacement and modification parts" does not apply to parts manufactured in Canada for export to the United States under the terms of the IPA of the US/Canadian BASA.
Therefore, FAA has determined that Viking Air does have the authority to manufacture parts for the accomplishment of this AD action.
We have made no changes to the final rule based on this comment.
Additional Information
Are there any changes from the NPRM? The STC holder issued a revision to the original type certificate because of a typographical error. Both the original and the revised STC (ST01243NY or SA01243NY) may be used.
Conclusion
What is FAA's final determination on this issue? We have carefully reviewed the available data and determined that air safety and the public interest require adopting the AD as proposed except for the changes discussed above and minor editorial corrections. We have determined that these changes and minor corrections:
--Are consistent with the intent that was proposed in the NPRM for correcting the unsafe condition; and
--Do not add any additional burden upon the public than was already proposed in the NPRM.
Docket Information
Where can I go to view the docket information? You may view the AD docket that contains information relating to this subject in person at the DMS Docket Offices between 9 a.m. and 5 p.m. (eastern standard time), Monday through Friday, except Federal holidays. The Docket Office (telephone 1-800-647-5227) is located on the plaza level of the Department of Transportation NASSIF Building at the street address stated in ADDRESSES. You may also view the AD docket on the Internet at http://dms.dot.gov.
Changes to 14 CFR Part 39--Effect on the AD
How does the revision to 14 CFR part 39 affect this AD? On July 10, 2002, the FAA published a new version of 14 CFR part 39 (67 FR 47997, July 22, 2002), which governs the FAA's AD system. This regulation now includes material that relates to altered products, special flight permits, and alternative methods of compliance. This material previously was included ineach individual AD. Since this material is included in 14 CFR part 39, we will not include it in future AD actions.
Costs of Compliance
How many airplanes does this AD impact? We estimate that this AD affects 11 airplanes in the U.S. registry.
What is the cost impact of this AD on owners/operators of the affected airplanes? We estimate the following costs to accomplish the modification:
Labor cost
Parts cost
Total cost per airplane
Total cost of U.S. operators
7.5 workhours $65 per hour = $488
$2,630 (The operator may return the original parts to Viking Air Ltd. for credit.).
$3,118
$34,298
Regulatory Findings
Will this AD impact various entities? We have 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.
Will this AD involve a significant rule or regulatory action? For the reasons discussed above, I certify that this AD:
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 summary of the costs to comply with this AD and placed it in the AD Docket. You may get a copy of this summary by sending a request to us at the address listed under ADDRESSES. Include "Docket No. FAA-2004-18606; Directorate Identifier 2004-CE-17-AD" in your request.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.
Adoption of the Amendment
Accordingly, under the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (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. FAA amends 39.13 by adding a new AD to read as follows: