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Proposed Rule

Airworthiness Directives; Short Brothers Model SD3-60 Series Airplanes

Document Details

Information about this document as published in the Federal Register.

Published Document

This document has been published in the Federal Register. Use the PDF linked in the document sidebar for the official electronic format.

Start Preamble

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Supplemental notice of proposed rulemaking; reopening of comment period.

SUMMARY:

This document revises an earlier proposed airworthiness directive (AD), applicable to all Short Brothers Model SD3-60 series airplanes, that would have required performing an inspection of the shear attachment fitting for the fin-to-fuselage front spar, and of the shear cleat for the fin root rib at the aft spar location for corrosion; reporting inspection results; and performing corrective action, if necessary. This new action revises the proposed rule by adding additional inspection areas, a repetitive borescope (intrascope) inspection, and applicable corrective actions per new Short Brothers information. This new action also revises the proposed rule by deleting the inspection report. The actions specified by this new proposed AD are intended to detect and correct corrosion in the area of the main spar web fittings of the vertical stabilizer, which could result in reduced structural integrity of the vertical stabilizer. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by April 26, 2005.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Start Printed Page 16765Attention: Rules Docket No. 2003-NM-127-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9 a.m. and 3 p.m., Monday through Friday, except Federal holidays. Comments may be submitted via fax to (425) 227-1232. Comments may also be sent via the Internet using the following address: 9-anm-nprmcomment@faa.gov. Comments sent via fax or the Internet must contain “Docket No. 2003-NM-127-AD” in the subject line and need not be submitted in triplicate. Comments sent via the Internet as attached electronic files must be formatted in Microsoft Word 97 or 2000 or ASCII text.

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.

Start Further Info

FOR FURTHER INFORMATION CONTACT:

Todd Thompson, Aerospace Engineer, International Branch, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-1175; fax (425) 227-1149.

End Further Info End Preamble Start Supplemental Information

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 action may be changed in light of the comments received.

Submit comments using the following format:

  • Organize comments issue-by-issue. For example, discuss a request to change the compliance time and a request to change the service bulletin reference as two separate issues.
  • For each issue, state what specific change to the proposed AD is being requested.
  • Include justification (e.g., reasons or data) for each request.

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 action must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 2003-NM-127-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. 2003-NM-127-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to add an airworthiness directive (AD), applicable to all Short Brothers Model SD3-60 series airplanes, was published as a notice of proposed rulemaking (NPRM) in the Federal Register on February 6, 2004 (69 FR 5769) (hereafter referred to as the “original NPRM”). The original NPRM would have required performing an inspection of the shear attachment fitting for the fin-to-fuselage front spar, and of the shear cleat for the fin root rib at the aft spar location for corrosion; reporting inspection results; and performing corrective action, if necessary. The original NPRM was prompted by reports of corrosion in the area of the main spar web fittings, which act as shear attachments for the vertical stabilizer. That condition, if not detected and corrected, could result in corrosion in the area of the main spar web fittings of the vertical stabilizer, which could result in reduced structural integrity of the vertical stabilizer.

Actions Since Issuance of the Original NPRM

Since the issuance of the original NPRM, the Civil Aviation Authority (CAA), which is the airworthiness authority for the United Kingdom, has issued British airworthiness directive G-2004-0005, which supersedes British airworthiness directive 004-11-2002, referenced in the original NPRM. The new British airworthiness directive requires inspections and replacements in accordance with Short Brothers Service Bulletin SD360-53-45, dated December 2003; and repetitive inspections in accordance with the Short Brothers Recommended Maintenance Manual. However, the maintenance manual has not been revised to include the repetitive inspections. The repetitive inspection information is included in Bombardier Temporary Revisions (TRs) TR360-MPSUPP-04 and TR360-MPSUPP-03, both dated August 20, 2003.

Relevant Service Information

Shorts has issued Short Brothers Service Bulletin SD360-53-45, dated December 2003, which supersedes Short Brothers Service Bulletin SD360-53-44, Revision 1, dated January 24, 2003 (referenced in the original NPRM as the appropriate source of service information). Service Bulletin SD360-53-45 describes procedures for inspecting new areas of the vertical stabilizer for corrosion and damage, doing repetitive inspections of areas with acceptable or no corrosion and damage, and replacing corroded or damaged parts with new parts.

Short Brothers Service Bulletin SD360-53-45, dated December 2003, refers to Short Brothers Recommended Maintenance Programme (Section 5-26-53, ATA 53-40, Item 12(d) and Section 5-26-55, ATA 55-30, Item 5(a)) as the source of service information for the repetitive borescope inspections. The repetitive inspections, which are not yet included in the general revisions of Short Brothers Recommended Maintenance Programme, are included in Bombardier TRs TR360-MPSUPP-04 and TR360-MPSUPP-03, both dated August 20, 2003.

Accomplishing the actions specified in the service information is intended to adequately address the unsafe condition.

The Civil Aviation Authority (CAA), the airworthiness authority for the United Kingdom, has classified this new service information as mandatory and issued British airworthiness directive G-2004-0005, issued March 2, 2004, to ensure the continued airworthiness of these airplanes in the United Kingdom. British airworthiness directive G-2004-0005, issued March 2, 2004, supersedes British airworthiness directive 004-11-2002 (referenced in the original NPRM).

Therefore, we have revised the supplemental NPRM to refer to the service bulletins and TRs described previously as the appropriate sources of service information for accomplishing the actions proposed in this supplemental NPRM.

Conclusion

Since these changes expand the scope of the original NPRM, we have Start Printed Page 16766determined that it is necessary to reopen the comment period to provide additional opportunity for public comment.

Clarification on Repetitive Inspections

The TRs described previously are intended to be inserted into the Airworthiness Limitations section of the Short Brothers Recommended Maintenance Programme. However, since the affected airplane models were in the certification process before the effective date of Section 25.1529 (“Instructions for Continued Airworthiness”) of the Federal Aviation Regulations (14 CFR 25.1529), which requires Airworthiness Limitations sections in airplane maintenance manuals, there is no Airworthiness Limitations section into which we can require insertion of the TRs. Therefore, instead of requiring the insertion of the TRs, we are requiring repetitive inspections, and any applicable corrective actions, in paragraph (c) of this supplemental NPRM. The recurring inspection interval in the TRs is 24 months, the same as this supplemental NPRM.

Cost Impact

The following table provides the estimated costs for U.S. operators to comply with this proposed AD.

Estimated Costs

ActionWork hoursAverage labor rate per hourPartsCost per airplaneNumber of U.S.-registered airplanesFleet cost
Inspection, per inspection cycle4$65None$26046$11,960, 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. 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.

Authority for This Rulemaking

The FAA's authority to issue rules regarding aviation safety is found in Title 49 of the United States Code. Subtitle I, section 106, describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the agency's authority.

This rulemaking is promulgated under the authority described in subtitle VII, part A, subpart III, section 44701, “General requirements.” Under that section, the FAA is charged with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this proposed AD.

Regulatory Impact

The regulations proposed herein would 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 proposal would not have federalism implications under Executive Order 13132.

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.

Start List of Subjects

List of Subjects in 14 CFR Part 39

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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:

Start Part

PART 39—AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Start Authority

Authority: 49 U.S.C. 106(g), 40113, 44701.

End Authority
[Amended]

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

Short Brothers PLC: Docket 2003-NM-127-AD.

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

Compliance: Required as indicated, unless accomplished previously.

To detect and correct corrosion in the area of the main spar web fittings of the vertical stabilizer, which could result in reduced structural integrity of the vertical stabilizer, accomplish the following:

Inspection and Previous Actions

(a) Except as provided by paragraphs (a)(1) and (a)(2) of this AD, within 4,800 flight hours or 90 days after the effective date of this AD, whichever occurs first, do a borescope inspection to detect corrosion of the shear attachment fittings of the vertical stabilizer, in accordance with the Accomplishment Instructions of Short Brothers Service Bulletin SD360-53-45, dated December 19, 2003.

(1) If an airplane (the shear attachment fitting) has been inspected in accordance with the Accomplishment Instructions of Short Brothers Service Bulletin SD360-53-44, Revision 1, dated January 24, 2003, before the effective date of this AD, and was found to have no corrosion on the fittings, then the initial inspection specified in paragraph (a) of this AD is not required.

(2) If the shear attachment fitting has been inspected in accordance with the Accomplishment Instructions of Short Brothers Service Bulletin SD360-53-44, Revision 1, dated January 24, 2003, and was found to have corrosion, but the corroded fitting is not yet replaced, then a review of the inspection results is required to determine if the corrosion was within the acceptable limits specified in Short Brothers Service Bulletin SD360-53-45, dated December 19, 2003. Start Printed Page 16767

Corrective Actions and Repetitive Inspections

(b) If any corrosion is found during the inspection required by paragraph (a) of this AD, do the applicable actions required by paragraph (b)(1) or (b)(2) of this AD.

(1) If any corrosion is within the limits specified in the Accomplishment Instructions of Short Brothers Service Bulletin SD360-53-45, dated December 19, 2003, do the actions required by paragraphs (b)(1)(i) and (b)(1)(ii) of this AD.

(i) Repeat the inspection required by the service bulletin at intervals not to exceed 6 months.

(ii) Within 18 months after the initial inspection required by paragraph (a) of this AD, replace all corroded shear attachment fittings in accordance with the Accomplishment Instructions of the service bulletin. Accomplishing the replacement ends the repetitive inspections required by paragraph (b)(1)(i) of this AD.

(2) If any corrosion is outside the limits specified in the Accomplishment Instructions of Short Brothers Service Bulletin SD360-53-45, dated December 19, 2003, before further flight, replace the corroded fitting with a new fitting, in accordance with the Accomplishment Instructions of the service bulletin.

(c) If no corrosion is found during the inspection required by paragraph (a) or if the fitting was replaced with a new fitting in accordance with Short Brothers Service Bulletin SD360-53-45, dated December 19, 2003: Do the actions in paragraphs (c)(1) and (c)(2) of this AD.

(1) Within 24 months after the initial inspection required by paragraph (a) of this AD or within 24 months after replacement of the fitting with a new one, whichever occurs later, do a borescope (intrascope) detailed inspection for corrosion in accordance with Part A of the Accomplishment Instructions of Short Brothers Service Bulletin SD360-53-45, dated December 19, 2003. Repeat this inspection thereafter at intervals not to exceed 24 months. Do corrective actions in accordance with paragraph (b) of this AD.

(2) Thereafter, except as provided in paragraph (f) of this AD, no alternative borescope inspections may be approved.

Previous Repetitive Inspections

(d) Borescope (intrascope) detailed inspections done before the effective date of this AD in accordance with Bombardier Temporary Revision (TR) TR360-MPSUPP-04 and TR360-MPSUPP-03, both dated August 20, 2003, are acceptable for compliance with the requirements of paragraph (c)(1) of this AD.

Disposition of Repairs for Corroded/Oversized Holes

(e) Where Short Brothers Service Bulletin SD360-53-45, dated December 19, 2003, says to contact the manufacturer for action on any corroded or oversized hole found during the inspection required by paragraph (a) or (c) of this AD, before further flight, repair in accordance with a method approved by either the Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate; or the Civil Aviation Authority (or its delegated agent).

Alternative Methods of Compliance

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

Note 2:

The subject of this AD is addressed in British airworthiness directive G-2004-0005, dated March 16, 2004.

Start Signature

Issued in Renton, Washington, on March 23, 2005.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.

End Signature End Part End Supplemental Information

[FR Doc. 05-6449 Filed 3-31-05; 8:45 am]

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