[Federal Register Volume 63, Number 152 (Friday, August 7, 1998)] [Proposed Rules] [Pages 42288-42290] From the Federal Register Online via the Government Publishing Office [www.gpo.gov] [FR Doc No: 98-21103] ----------------------------------------------------------------------- DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [Docket No. 98-NM-138-AD] RIN 2120-AA64 Airworthiness Directives; Short Brothers Model SD3-60 SHERPA Series Airplanes AGENCY: Federal Aviation Administration, DOT. ACTION: Notice of proposed rulemaking (NPRM). ----------------------------------------------------------------------- SUMMARY: This document proposes the adoption of a new airworthiness directive (AD) that is applicable to all Short Brothers Model SD3-60 SHERPA series airplanes. This proposal would require an initial cleaning and visual inspection of the distance piece and adjacent side plates of the fuselage wing strut pick-up of the left- and right-stub wings to detect corrosion; rework or replacement of damaged components; and, for certain conditions, follow-on repetitive cleaning and visual inspections of reworked components. This proposal is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by the proposed AD are intended to detect and correct corrosion of the distance piece and adjacent side plates, which could result in reduced strength of the wing strut attachment to the stub wing on the fuselage, and consequent reduced structural integrity of the main wing. DATES: Comments must be received by September 8, 1998. ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 98-NM-138-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except Federal holidays. The service information referenced in the proposed rule may be obtained from Short Brothers, Airworthiness & Engineering Quality, P.O. Box 241, Airport Road, Belfast BT3 9DZ, Northern Ireland. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington. FOR FURTHER INFORMATION CONTACT: Norman B. Martenson, Manager, International Branch, ANM-116, FAA, [[Page 42289]] Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-2110; fax (425) 227-1149. SUPPLEMENTARY INFORMATION: Comments Invited Interested persons are invited to participate in the making of the proposed rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this notice may be changed in light of the comments received. Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report summarizing each FAA-public contact concerned with the substance of this proposal will be filed in the Rules Docket. Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this notice must submit a self-addressed, stamped postcard on which the following statement is made: ``Comments to Docket Number 98-NM-138-AD.'' The postcard will be date stamped and returned to the commenter. Availability of NPRMs Any person may obtain a copy of this NPRM by submitting a request to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 98-NM-138-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Discussion The Civil Aviation Authority (CAA), which is the airworthiness authority for the United Kingdom, notified the FAA that an unsafe condition may exist on all Short Brothers Model SD3-60 SHERPA series airplanes. The CAA advises that corrosion has been detected on the horizontal leg of the distance piece and adjacent faces of the side plates of the wing strut pick-up on the left- and right-stub wing. This corrosion occurs from debris being thrown into pockets in the distance piece, which is adjacent to the main landing gear wheels. Such corrosion of the distance piece and adjacent side plates, if not corrected, could result in reduced strength of the wing strut attachment to the stub wing on the fuselage, and consequent reduced structural integrity of the main wing. Explanation of Relevant Service Information Shorts has issued Service Bulletin SD3-60 SHERPA-53-2, dated November 4, 1997, which describes procedures for an initial cleaning and visual inspection of the distance piece and adjacent side plates of the fuselage wing strut pick-up of the left- and right-stub wings to detect corrosion; rework or replacement of damaged components, if necessary; and, for certain conditions, follow-on repetitive cleaning and visual inspections of reworked components. Accomplishment of the actions specified in the service bulletin is intended to adequately address the identified unsafe condition. The CAA classified this service bulletin as mandatory and issued British airworthiness directive 004-11-97 in order to assure the continued airworthiness of these airplanes in the United Kingdom. FAA's Conclusions This airplane model is manufactured in the United Kingdom and is type certificated for operation in the United States under the provisions of section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the applicable bilateral airworthiness agreement. Pursuant to this bilateral airworthiness agreement, the CAA has kept the FAA informed of the situation described above. The FAA has examined the findings of the CAA, reviewed all available information, and determined that AD action is necessary for products of this type design that are certificated for operation in the United States. Explanation of Requirements of Proposed Rule Since an unsafe condition has been identified that is likely to exist or develop on other airplanes of the same type design registered in the United States, the proposed AD would require accomplishment of the actions specified in the service bulletin described previously, except as discussed below. The proposed AD also would require that operators report inspection findings to the manufacturer. Differences between Proposed Rule and Service Bulletin Operators should note that, although the service bulletin specifies that the manufacturer may be contacted for disposition of corrosion that exceeds certain limits, this proposal would require the repair of those conditions to be accomplished in accordance with a method approved by either the FAA or the CAA (or its delegated agent). In light of the type of repair that would be required to address the identified unsafe condition, and in consonance with existing bilateral airworthiness agreements, the FAA has determined that, for this proposed AD, a repair approved by either the FAA or the CAA would be acceptable for compliance with this proposed AD. Cost Impact The FAA estimates that 28 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 5 work hours per airplane to accomplish the proposed inspection, and that the average labor rate is $60 per work hour. Based on these figures, the cost impact of the proposed AD on U.S. operators is estimated to be $8,400, or $300 per airplane, per inspection cycle. The cost impact figure discussed above is based on assumptions that no operator has yet accomplished any of the proposed requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted. Regulatory Impact The regulations proposed herein would not have substantial direct effects 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, in accordance with Executive Order 12612, it is determined that this proposal would not have sufficient federalism implications to warrant the preparation of a Federalism Assessment. For the reasons discussed above, I certify that 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) if promulgated, 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 copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES. [[Page 42290]] List of Subjects in 14 CFR Part 39 Air transportation, Aircraft, Aviation safety, Safety. The Proposed Amendment Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend 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: Short Brothers PLC: Docket 98-NM-138-AD. Applicability: All Model SD3-60 SHERPA series airplanes, certificated in any category. Note 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (e) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it. Compliance: Required as indicated, unless accomplished previously. To detect and correct corrosion of the distance piece and adjacent side plates of the fuselage wing strut pick-up of the left- and right-stub wings, which could result in reduced strength of the wing strut attachment to the stub wing on the fuselage, and consequent reduced structural integrity of the main wing, accomplish the following: (a) Within 90 days after the effective date of this AD, clean the pockets in the horizontal and vertical legs of the distance piece and adjacent faces of the side plates at the wing strut pick- up area on the stub wing, and perform a visual inspection to detect corrosion; in accordance with Shorts Service Bulletin SD3-60 SHERPA- 53-2, dated November 4, 1997. (b) If no corrosion is detected during the inspection required by paragraph (a) of this AD, prior to further flight, apply additional corrosion protection treatment in accordance with Shorts Service Bulletin SD3-60 SHERPA-53-2, dated November 4, 1997. (c) If any corrosion is detected, prior to further flight, after cleaning and removing the corrosion from the distance piece and side plates in accordance with Shorts Service Bulletin SD3-60 SHERPA-53- 2, dated November 4, 1997, accomplish paragraph (c)(1) or (c)(2) of this AD, as applicable. (1) If the depth of corrosion is within the limits specified in the service bulletin, apply additional corrosion protection treatment in accordance with the service bulletin. (2) If the depth of corrosion is outside the limits specified in the service bulletin, accomplish either paragraph (c)(2)(i) or (c)(2)(ii) of this AD. Thereafter, repeat the detailed visual inspection required by paragraph (a) of this AD at intervals not to exceed 600 hours time-in-service or 90 days, whichever occurs first. (i) Rework the damaged components in accordance with a method approved by either the Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate; or the Civil Aviation Authority of the United Kingdom (or its delegated agent). Thereafter, repeat the detailed visual inspection required by paragraph (a) of this AD at intervals not to exceed 600 hours time-in-service or 90 days, whichever occurs first. (ii) Replace the damaged components with new components in accordance with Shorts SD3-60 Sherpa Maintenance Programme Manual, Section 5-26-57, page 9, dated July 17, 1995. (d) Within 10 days after accomplishing the initial cleaning and inspection required by paragraph (a) of this AD, submit a report of the inspection results (both positive and negative findings) to Short Brothers, PLC. Information collection requirements contained in this regulation have been approved by the Office of Management and Budget (OMB) under the provisions of the Paperwork Reduction Act of 1980 (44 U.S.C. 3501 et seq.) and have been assigned OMB Control Number 2120-0056. (e) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, International Branch, ANM-116. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, International Branch, ANM-116. Note 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the International Branch, ANM-116. (f) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished. Note 3: The subject of this AD is addressed in British airworthiness directive 004-11-97. Issued in Renton, Washington, on July 31, 1998. Darrell M. Pederson, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 98-21103 Filed 8-6-98; 8:45 am] BILLING CODE 4910-13-P