AD 2004-13-21

This amendment adopts a new airworthiness directive (AD), applicable to all Short Brothers Model SD3-60 SHERPA series airplanes, that requires repetitive inspections and torque tests for discrepancies of certain bolts and rivets; and related investigative and corrective actions. This action is necessary to detect and correct loose bolts that attach the vertical stabilizer to the horizontal stabilizer, and pulled or loose rivets in the upper shear angles, which could result in reduced structural integrity of the vertical stabilizer. This action is intended to address the identified unsafe condition.

Final rule.

2004-13-21 Short Brothers PLC: Amendment 39-13703. Docket 2003-NM- 200-AD.

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

Compliance: Required as indicated, unless accomplished previously.

To detect and correct loose bolts that attach the vertical stabilizer to the horizontal stabilizer, and pulled or loose rivets in the upper shear angles, which could result in reduced structural integrity of the vertical stabilizer, accomplish the following:

Repetitive Inspections and Torque Tests and Related Investigative Action

(a) Prior to the accumulation of 1,500 total flight hours, or within 2 months after the effective date of this AD, whichever occurs later: Perform a detailed inspection, including a torque test, to detect discrepancies in the bolts or bolt holes that attach the vertical stabilizer to the horizontal stabilizer; and to detect loose or pulled rivets in the upper shear angles. Repeat the detailed inspection and torque test at intervals not to exceed 1,500 flight hours. If any discrepancy is found in the bolts or bolt holes, do the related investigative action before further flight. Accomplish all actions in accordance with the Accomplishment Instructions of Short Brothers Service Bulletin SD3-60 Sherpa-55-1, dated June 6, 2003.

Note 1: For the purposes of this AD, a detailed inspection is defined as: "An intensive visual examination of a specific structural area, system, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at intensity deemed appropriate by the inspector. Inspection aids such as mirror, magnifying lenses, etc., may be used. Surface cleaning and elaborate access procedures may be required."

Related Corrective Actions

(b) If any discrepancy is found during any inspection or torque test required by paragraph (a) of this AD: Before further flight, repair in accordance with the Accomplishment Instructions of Short Brothers Service Bulletin SD3-60 Sherpa-55-1, dated June 6, 2003. Where the service bulletin specifies to contact the manufacturer for disposition of certain repair conditions: Before further flight, repair per a method approved by either the Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate; or the Civil Aviation Authority or its delegated agent.

No Reporting Requirement

(c) Although the service bulletin referenced in this AD specifies to submit certain information to the manufacturer, this AD does not include such a requirement.

Alternative Methods of Compliance

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

Incorporation by Reference

(e) Unless otherwise specified in this AD, the actions shall be done in accordance with Short Brothers Service Bulletin SD3-60 Sherpa-55-1, datedJune 6, 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, or go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html .

Note 2: The subject of this AD is addressed in British airworthiness directive 001-06-2003.

Effective Date

(f) 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 SHERPA series airplanes was published in the Federal Register on March 25, 2004 (69 FR 15266). That action proposed to require repetitive inspections and torque tests for discrepancies of certain bolts and rivets; and related investigative and corrective actions.

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

The FAA has determined that air safety and the public interest require the adoption of the rule as proposed.

Cost Impact

The FAA estimates that 27 airplanes of U.S. registry will be affected by this AD, that it will take approximately 5 work hours per airplane to accomplishthe required inspections and torque tests, and that the average labor rate is $65 per work hour. Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $8,775, or $325 per airplane, per inspection/test cycle.

The cost impact figure discussed above is 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 the specific 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: