[Federal Register Volume 70, Number 62 (Friday, April 1, 2005)]
[Proposed Rules]
[Pages 16764-16767]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-6449]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2003-NM-127-AD]
RIN 2120-AA64


Airworthiness Directives; Short Brothers Model SD3-60 Series 
Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Supplemental notice of proposed rulemaking; reopening of 
comment period.

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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,

[[Page 16765]]

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: 
[email protected]. 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.

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.
    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

[[Page 16766]]

determined 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
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                                                                                                                    Number of
                                                         Average                                      Cost per        U.S.-
                Action                   Work hours    labor rate                Parts                airplane     registered          Fleet cost
                                                        per hour                                                    airplanes
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Inspection, per inspection cycle......            4           $65   None..........................         $260            46   $11,960, per inspection
                                                                                                                                 cycle.
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    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.

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 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.

[[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.


    Issued in Renton, Washington, on March 23, 2005.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 05-6449 Filed 3-31-05; 8:45 am]
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