AD 2004-13-08

This amendment adopts a new airworthiness directive (AD), applicable to all Short Brothers Model SD3-60 series airplanes. This AD requires inspection of the welded joints of the balance weight brackets for the left and right elevator trim tabs for cracking; repetitive inspections, as applicable; and corrective actions including the eventual replacement of all brackets, which constitutes terminating action for the repetitive inspections. This action is necessary to prevent the loss of the balance weight for the elevator trim tab, which could result in incorrect trim during takeoff and landing, and reduced controllability of the airplane. This action is intended to address the identified unsafe condition.

Final rule.

2004-13-08 Short Brothers PLC: Amendment 39-13690. Docket 2003-NM- 236-AD.

Applicability: All Model SD3-60 series airplanes, certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent the loss of the balance weight for the elevator trim tab, which could result in incorrect trim during takeoff and landing, and reduced controllability of the airplane, accomplish the following:

Service Bulletin Reference

(a) The term "service bulletin," as used in this AD, means the Accomplishment Instructions of Short Brothers Service Bulletin SD360-55-20, dated June 26, 2003.

Initial Inspection

(b) Within 2 months after the effective date of this AD: Do a dye penetrant inspection for cracking in the welded joints of the balance weight brackets for the left and right elevator trim tabs, in accordance with the service bulletin.

Investigative and Corrective Actions if No Cracking Is Found

(c) If no cracking is foundduring the inspection required by paragraph (b) of this AD, do the actions required by paragraphs (c)(1) and (c)(2) of this AD at the applicable compliance times.

(1) Repeat the inspection required by paragraph (b) of this AD at intervals not to exceed 4,800 flight hours until the bracket is replaced per paragraph (c)(2) or (d) of this AD.

(2) Prior to the accumulation of 28,800 total flight hours, or within 6 months after the effective date of this AD, whichever occurs later: Replace any bracket that has not been replaced per paragraph (d) of this AD with a new bracket or with a serviceable bracket that has been inspected in accordance with paragraph (b) of this AD. Replace in accordance with the service bulletin. Replacement of the brackets constitutes terminating action for the repetitive inspections required by paragraph (c)(1) of this AD.

Corrective Actions if Any Cracking Is Found

(d) If any cracking is found during any inspection required by paragraph (b) or(c) of this AD: Before further flight, accomplish the applicable action in paragraph (d)(1) or (d)(2) of this AD in accordance with the service bulletin.

(1) For airplanes that have accumulated less than 28,800 flight hours and on which all cracking on brackets is less than 0.25 inch in length: Repair the affected bracket in accordance with Part B of the service bulletin (including the additional dye penetrant inspection of the repaired welded joint) and repeat the inspection required by paragraph (b) of this AD at intervals not to exceed 4,800 flight hours; or replace the bracket in accordance with paragraph (d)(2) of this AD. Replacement of the bracket constitutes terminating action for the repetitive inspections.

(2) For any airplane on which any cracking on a bracket is 0.25 inch in length or greater, and for any airplane that has accumulated 28,800 flight hours or more on which any cracking of any length is found on a bracket: Replace the affected bracket with a new bracket or with a serviceable bracket that has been inspected in accordance with paragraph (b) of this AD. Replacement of the bracket constitutes terminating action for the repetitive inspections required by paragraph (d)(1) of this AD.

Refitting

(e) Before further flight following any inspection per paragraphs (b) or (c) of this AD; or before further flight following repair or replacement of a bracket per paragraphs (c)(2) or (d) of this AD: Refit the balance weights, covers, and trim tabs, in accordance with the service bulletin. Where the service bulletin specifies to contact the manufacturer for disposition of certain conditions while refitting, obtain further disposition instructions from the Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate; or the Civil Aviation Authority (CAA) (or its delegated agent).

Parts Installation

(f) As of the effective date of this AD, no person may install on any airplane a balance weight bracket unless the welded joint has been inspected in accordance with paragraph (b) of this AD.

Alternative Methods of Compliance

(g) In accordance with 14 CFR 39.19, the Manager, International Branch, ANM-116, is authorized to approve alternative methods of compliance for this AD.

Incorporation by Reference

(h) Unless otherwise specified in this AD the actions shall be done in accordance with Short Brothers Service Bulletin SD360-55-20, dated June 26, 2003. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Short Brothers, Airworthiness & Engineering Quality, P.O. Box 241, Airport Road, Belfast BT3 9DZ, Northern Ireland. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call (202) 741-6030, orgo to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html .

Note 1: The subject of this AD is addressed in British airworthiness directive 009-06-2003.

Effective Date

(i) This amendment becomes effective on August 3, 2004.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an airworthiness directive (AD) that is applicable to all Short Brothers Model SD3-60 series airplanes was published in the Federal Register on April 22, 2004 (69 FR 21766). That action proposed to require inspection of the welded joints of the balance weight brackets for the left and right elevator trim tabs for cracking; repetitive inspections, as applicable; and corrective actions including the eventual replacement of all brackets, which would constitute terminating action for the repetitive inspections.

Comments

Interested persons have been afforded an opportunity to participate in the making of this amendment. No comments were submitted in response to the proposal or the FAA's determination of the cost to the public.

Conclusion

We have determined that air safety and the public interest require the adoption of the rule as proposed.

Cost ImpactWe estimate that 42 airplanes of U.S. registry will be affected by this AD, that it will take approximately 12 work hours per airplane to accomplish the required inspections, and that the average labor rate is $65 per work hour. Based on these figures, the cost impact of this action on U.S. operators is estimated to be $32,760, or $780 per airplane.

It will take approximately 8 work hours per airplane to accomplish the replacement of the brackets. Required parts will cost approximately $632 per airplane. Based on these figures, the cost impact of this action on U.S. operators is estimated to be $48,384, or $1,152 per airplane.

The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform thespecific actions actually required by the AD. These figures typically do not include incidental costs, such as the time required to gain access and close up, planning time, or time necessitated by other administrative actions.

Regulatory Impact

The regulations adopted herein 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. Therefore, it is determined that this final rule does not have federalism implications under Executive Order 13132.

For the reasons discussed above, I certify that this action (1) is not a "significant regulatory action" under Executive Order 12866; (2) is not a "significant rule" under 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. A final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it may be obtained from the Rules Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.

Adoption of the Amendment

Accordingly, pursuant to 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.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by adding the following new airworthiness directive: