AD 98-20-32

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AD Number:
98-20-32
Document Type:
AD Final Rules
Docket Number:
98-NM-138-AD
Subject Heading:
Airworthiness Directives; Short Brothers Model SD3-60 SHERPA Series Airplanes
Subject:
Side Plates At Fuselage Wing Strut Pick-Up Area
Status:
Current
Citation:
Federal Register: September 25, 1998 (Volume 63, Number 186)
Citation Publish Date:
09/25/1998
Effective Date:
10/30/1998
Make:
Short Brothers PLC
Model:
SD3-60 SHERPA
Product Type:
Aircraft
Product Subtype:
Large Airplane
Affected AD:
Superseded AD:
Affected By:
Superseded By:
Service/Office:
Office of Primary Responsibility:
CFR Part Reference:
Part 39 [63 FR 51281 No. 186 09/25/98]
Comments:
AIRWORTHINESS DIRECTIVES FINAL RULES: 98-20-32
CITATION:   [Federal Register: September 25, 1998 (Volume 63, Number 186)]

PAGE NUMBER:   [Page 51281]

DOCKET NUMBER:   98-NM-138-AD

AMENDMENT:   39-10799

AD NUMBER:   98-20-32

SUBJECT HEADING:   Airworthiness Directives; Short Brothers Model SD3-60 SHERPA Series Airplanes

ACTION:   Final rule

SUMMARY:   This amendment adopts a new airworthiness directive (AD), applicable to all Short Brothers Model SD3-60 SHERPA series airplanes, that requires 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 amendment is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by this 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:   Effective October 30, 1998. The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of October 30, 1998.

ADDRESSES:   The service information referenced in this AD 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 Federal Aviation Administration (FAA), Transport Airplane Directorate, Rules Docket, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT:   Norman B. Martenson, Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-2110; fax (425) 227-1149.

SUPPLEMENTARY INFORMATION:  
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 August 7, 1998 (63 FR 42288). That action proposed to 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.

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 28 airplanes of U.S. registry will be affected by this AD, that it will take approximately 5 work hours per airplane to accomplish the required inspection, and that the average labor rate is $60 per work hour. Based on these figures, the cost impact of the inspection required by this 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 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 adopted herein will 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 final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.

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.

§ 39.13 [Amended]
2. Section 39.13 is amended by adding the following new airworthiness directive:

REGULATORY TEXT:  
98-20-32 SHORT BROTHERS PLC: Amendment 39-10799. 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.

(g) Except as provided by paragraphs (c)(2)(i), (c)(2)(ii), and (d) of this AD, the actions shall be done in accordance with Shorts Service Bulletin SD3-60 SHERPA-53-2, dated November 4, 1997. 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 Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

NOTE 3: The subject of this AD is addressed in British airworthiness directive 004-11-97.

(h) This amendment becomes effective on October 30, 1998.

FOOTER: