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###### Department of Transportation

###### Federal Aviation Administration 

          - 14 CFR Part 39 
          - [Docket No. 2003-NM-127-AD] 
          - RIN 2120-AA64 

# 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 series airplanes. This proposal would require 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 action is necessary 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 March 8, 2004. 

# ADDRESSES:

                        Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: 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 for Windows 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. 

# 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. 

# 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.                           ( print page 5770)    

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 

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 series airplanes. The CAA advises that operators have reported corrosion in the area of the main spar web fittings, which act as shear attachments for the vertical stabilizer. This condition, if not detected and corrected, could result in reduced structural integrity of the vertical stabilizer. 

## Explanation of Relevant Service Information 

Shorts has issued Short Brothers Service Bulletin SD360-53-44, Revision 1, dated January 24, 2003, which describes procedures for 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, and submitting an inspection report. The CAA classified this service bulletin as mandatory and issued British airworthiness directive 004-11-2002, 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 described below.

## Differences Between Proposed Rule and Service Bulletin

Although the service bulletin specifies that operators may contact the manufacturer for disposition of repairs, this proposal would require operators to repair those conditions per 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 unsafe condition, and consistent with existing bilateral airworthiness agreements, we have 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.

## Interim Action

This proposed AD is considered to be interim action. The inspection reports required by this proposed AD will enable the manufacturer to obtain better insight into the nature, cause, and extent of the corrosion, and eventually to develop final action to address the unsafe condition. Once final action has been identified, we may consider further rulemaking.

## Cost Impact

The FAA estimates that 46 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 3 work hours per airplane to accomplish the proposed inspection, and that the average labor rate is $65 per work hour. Based on these figures, the cost impact of the proposed AD on U.S. operators is estimated to be $8,970, or $195 per airplane.

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 proposed 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 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**                    .                

# 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:

      ( print page 5771)    

# 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 

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

(a) Within 6 months after the effective date of this AD, perform a detailed inspection to detect corrosion 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, in accordance with the Accomplishment Instruction of Short Brothers Service Bulletin SD360-53-44, Revision 1, dated January 24, 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.” 

## Disposition of Repairs

(b) If any corrosion is detected during the inspection required by paragraph (a) of this AD, 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).

## Inspection Report

                                (c) Submit a report of the findings (both positive and negative) of the inspection required by paragraph (a) of this AD to Short Brothers, Airworthiness & Engineering Quality, P.O. Box 241, Airport Road, Belfast BT3 9DZ, Northern Ireland, or as specified in the Shorts service bulletin, at the applicable time specified in paragraph (c)(1) or (c)(2) of this AD. The report must include the inspection results, a description of any discrepancies found, the airplane serial number, and the number of landings and flight hours on the airplane. Under the provisions of the Paperwork Reduction Act of 1980 (44 U.S.C. 3501*et seq.*), the Office of Management and Budget (OMB) has approved the information collection requirements contained in this AD and has assigned OMB Control Number 2120-0056.                            

(1) If the inspection was done after the effective date of this AD: Submit the report within 10 days after the inspection.

(2) If the inspection was accomplished prior to the effective date of this AD: Submit the report within 10 days after the effective date of this AD.

## Alternative Methods of Compliance

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

# Note 2:

The subject of this AD is addressed in British airworthiness directive 004-11-2002. 

Issued in Renton, Washington, on January 29, 2004.

Kalene C. Yanamura,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

[FR Doc. 04-2471 Filed 2-5-04; 8:45 am]

BILLING CODE 4910-13-P