[Federal Register Volume 64, Number 197 (Wednesday, October 13, 1999)]
[Rules and Regulations]
[Pages 55409-55411]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-26277]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-NM-137-AD; Amendment 39-11367; AD 99-21-22]
RIN 2120-AA64
Airworthiness Directives; Short Brothers Model SD3-30, SD3-60,
SD3 SHERPA, and SD3-60 SHERPA Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule.
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SUMMARY: This amendment adopts a new airworthiness directive (AD),
applicable to all Short Brothers Model SD3-30, SD3-60, SD3 SHERPA, and
SD3-60 SHERPA series airplanes, that requires a visual inspection to
detect corrosion of the shear decks and ribs of the left and right stub
wings; follow-on corrective actions, if necessary; and drilling of new
drain holes in the lower shear decks. 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 prevent corrosion of the stub wing shear decks and ribs,
which could result in cracking or failure of the stub wing structure.
DATES: Effective November 17, 1999.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of November 17, 1999.
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 SD3-30,
SD3-60, SD3 SHERPA, and SD3-60 SHERPA series airplanes was published in
the Federal Register on June 23, 1999 (64 FR 33439). That action
proposed to require a one-time borescope inspection to detect corrosion
of the shear decks and ribs of the left and right stub wings, follow-on
corrective actions, if necessary; and drilling of new drain holes in
the lower shear decks.
Comments Received
Interested persons have been afforded an opportunity to participate
in the making of this amendment. Due consideration has been given to
the comments received.
Request To Revise Inspection Method
One commenter suggests that the proposed AD be revised to include
instructions to remove the main landing gear (MLG) forward pintle pin
(which requires removal of the wheel lever assemblies) and to steam
clean the areas identified by the referenced service bulletin. The
commenter also suggests that all reference to use of a borescope be
deleted to prevent misinterpretation. The commenter states that the
proposed AD dictates a different inspection method than the referenced
manufacturer's service bulletin, since it does not reference removing
the MLG or steam cleaning the area, and requires a borescope
inspection. Such a method may actually degrade safety, since without
removal of the MLG forward pintle pins, thorough cleaning and
subsequent inspection of the area cannot be accomplished. The commenter
states that most technicians
[[Page 55410]]
would interpret the requirement to use a borescope to mean that removal
of the MLG is not required, since the purpose of a borescope is to
enable inspection without disassembly.
The FAA has determined that clarification of the AD is necessary.
The intent of the AD is to require the same inspection methods
specified in the referenced service bulletins. The actions required by
paragraph (a) of the AD are specifically required to be accomplished in
accordance with Part A of the Accomplishment Instructions of the
applicable service bulletin. Part A includes instructions for removal
of the port and starboard MLG, and steam cleaning of the affected area,
prior to inspection. Part A, paragraph 7., also specifies to ``visually
inspect inner surfaces and interfaces between ribs for corrosion using
a borescope.'' The FAA does not specify in an AD each action described
in the referenced service information, since such restatement would be
unnecessarily duplicative and could result in misunderstanding of the
requirements. However, to avoid any confusion as to the actions
required by this AD, the FAA has revised paragraph (a) of the AD to
require that all actions in Part A of the service bulletin be
accomplished. The FAA has also restated the borescope inspection
requirement to specify a ``visual inspection using a borescope.''
Request To Allow Use of Alternate Service Information
One commenter requests that the proposed AD be revised to allow
accomplishment of the required inspections on Short Brothers Model SD3-
60 SHERPA airplanes having serial numbers SH3420 through SH3428 in
accordance with Shorts Service Bulletin SD360-53-43, Revision 1, dated
November 27, 1998. This service bulletin was specified in the proposed
AD as the appropriate source of service information for Model SD3-60
airplanes, and SD360-Sherpa-53-4, dated November 27, 1998, was
specified as appropriate for Model SD3-60 SHERPA airplanes. The
commenter provides documentation showing that the airplane manufacturer
has previously accomplished service bulletin SD360-53-43 on certain
Model SD3-60 SHERPA airplanes, and requests that the FAA consider such
action to be adequate for compliance with the inspection required by
this AD.
The FAA concurs. The actions described in Shorts Service Bulletins
SD360-53-43, Revision 1, and SD360-Sherpa-53-4 are substantially
equivalent. The FAA has determined that for Model SD3-60 SHERPA series
airplanes, inspections accomplished in accordance with SD360-53-43,
dated November 4, 1997, or Revision 1, dated November 27, 1998, are
acceptable for compliance with the initial inspection required by
paragraph (a) of this AD. A ``NOTE'' has been added to the final rule
to provide such credit.
Conclusion
After careful review of the available data, including the comments
noted above, the FAA has determined that air safety and the public
interest require the adoption of the rule with the changes described
previously. The FAA has determined that these changes will neither
increase the economic burden on any operator nor increase the scope of
the AD.
Cost Impact
The FAA estimates that 112 airplanes of U.S. registry will be
affected by this AD, that it will take approximately 100 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 AD on U.S. operators is estimated to be $672,000, or
$6,000 per airplane.
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.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
99-21-22 Short Brothers PLC: Amendment 39-11367. Docket 98-NM-137-
AD.
Applicability: All Model SD3-30, SD3-60, SD3 SHERPA, and 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 prevent corrosion of the stub wing shear decks and ribs,
which could result in cracking or failure of the stub wing
structure, accomplish the following:
Inspection and Corrective Actions
(a) Within 6 months after the effective date of this AD,
accomplish all actions, including a visual inspection using a
borescope, specified in Part A of the Accomplishment Instructions of
the applicable Shorts Service Bulletin specified below, all dated
November 27, 1998 (hereinafter referred to as the applicable service
bulletin), in the areas of the stub wing shear decks and ribs to
detect corrosion, and drill new drain holes in the lower shear
decks, in accordance with the applicable service bulletin:
SD330-53-68 (for Model SD3-30 series airplanes);
SD360-53-43, Revision 1 (for Model SD3-60 series
airplanes);
SD3 Sherpa-53-4 (for Model SD3 SHERPA series
airplanes); and
[[Page 55411]]
SD360-Sherpa-53-4 (for Model SD3-60 SHERPA series
airplanes).
Note 2: In the case where no corrosion is detected during the
inspection described in Part A of the Accomplishment Instructions of
the applicable service bulletin, the service bulletin specifies
accomplishment of follow-on repetitive inspections of this area as
specified in Short Brothers Aircraft Maintenance Programme, Chapter
5-26-57.
Note 3: For Model SD3-60 SHERPA series airplanes, accomplishment
of the actions required by paragraph (a) of this AD in accordance
with Shorts Service Bulletin SD360-53-43, dated November 4, 1997, or
Revision 1, dated November 27, 1998, is acceptable for compliance
with the requirements of that paragraph.
(b) Except as provided by paragraph (c) of this AD: If any
corrosion is detected during the inspection required by paragraph
(a) of this AD, prior to further flight, accomplish corrective
actions (i.e., additional inspections, removal of corrosion,
replacement of components), as applicable, in accordance with Part B
of the Accomplishment Instructions of the applicable service
bulletin. Thereafter, repeat the inspection required by paragraph
(a) of this AD at intervals not to exceed 12 months.
(c) If any corrosion condition is found for which the applicable
service bulletin specifies that Short Brothers is to be contacted
for an appropriate repair action: Prior to 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 (CAA) of the United Kingdom (or its
delegated agent).
Reporting Requirement
(d) Within 10 days after accomplishment of the initial
inspection required by paragraph (a) of this AD, or within 30 days
after the effective date of this AD, whichever occurs later, submit
a report of the inspection findings (positive or negative) to: Team
Leader, Service Engineering-Aerospace Customer Support Short
Brothers plc, Belfast, N. Ireland. 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.
Alternative Methods of Compliance
(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 4: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the International Branch, ANM-116.
Special Flight Permits
(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.
Incorporation by Reference
(g) The actions shall be done in accordance with Shorts Service
Bulletin SD330-53-68, dated November 27, 1998, Shorts Service
Bulletin SD360-53-43, Revision 1, dated November 27, 1998, Shorts
Service Bulletin SD3 Sherpa-53-4, dated November 27, 1998, or Shorts
Service Bulletin SD360-Sherpa-53-4, dated November 27, 1998; as
applicable. 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 5: The subject of this AD is addressed in British
airworthiness directives 006-11-97, 006-11-98, 007-11-98, and 008-
11-98.
(h) This amendment becomes effective on November 17, 1999.
Issued in Renton, Washington, on October 4, 1999.
D. L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 99-26277 Filed 10-12-99; 8:45 am]
BILLING CODE 4910-13-P
