[Federal Register Volume 63, Number 152 (Friday, August 7, 1998)]
[Proposed Rules]
[Pages 42288-42290]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-21103]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-NM-138-AD]
RIN 2120-AA64
Airworthiness Directives; Short Brothers Model SD3-60 SHERPA
Series Airplanes
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
SHERPA series airplanes. This proposal would 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. This proposal is prompted by
issuance of mandatory continuing airworthiness information by a foreign
civil airworthiness authority. The actions specified by the proposed 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: Comments must be received by September 8, 1998.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 98-NM-138-AD, 1601 Lind Avenue, SW.,
Renton, Washington 98055-4056. Comments may be inspected at this
location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except
Federal holidays.
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: Norman B. Martenson, Manager,
International Branch, ANM-116, FAA,
[[Page 42289]]
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton,
Washington 98055-4056; telephone (425) 227-2110; 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 notice may be changed in
light of the comments received.
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 notice must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket Number 98-NM-138-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. 98-NM-138-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 SHERPA series
airplanes. The CAA advises that corrosion has been detected on the
horizontal leg of the distance piece and adjacent faces of the side
plates of the wing strut pick-up on the left- and right-stub wing. This
corrosion occurs from debris being thrown into pockets in the distance
piece, which is adjacent to the main landing gear wheels. Such
corrosion of the distance piece and adjacent side plates, if not
corrected, 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.
Explanation of Relevant Service Information
Shorts has issued Service Bulletin SD3-60 SHERPA-53-2, dated
November 4, 1997, which describes procedures for 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, if
necessary; and, for certain conditions, follow-on repetitive cleaning
and visual inspections of reworked components. Accomplishment of the
actions specified in the service bulletin is intended to adequately
address the identified unsafe condition. The CAA classified this
service bulletin as mandatory and issued British airworthiness
directive 004-11-97 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 discussed below. The proposed AD also would require that
operators report inspection findings to the manufacturer.
Differences between Proposed Rule and Service Bulletin
Operators should note that, although the service bulletin specifies
that the manufacturer may be contacted for disposition of corrosion
that exceeds certain limits, this proposal would require the repair of
those conditions to be accomplished in accordance with 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
identified unsafe condition, and in consonance with existing bilateral
airworthiness agreements, the FAA has 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.
Cost Impact
The FAA estimates that 28 airplanes of U.S. registry would be
affected by this proposed AD, that it would take approximately 5 work
hours per airplane to accomplish the proposed inspection, and that the
average labor rate is $60 per work hour. Based on these figures, the
cost impact of the proposed 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 proposed 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 proposed herein would 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
proposal would not have sufficient federalism implications to warrant
the preparation of a Federalism Assessment.
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.
[[Page 42290]]
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 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.
Note 3: The subject of this AD is addressed in British
airworthiness directive 004-11-97.
Issued in Renton, Washington, on July 31, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 98-21103 Filed 8-6-98; 8:45 am]
BILLING CODE 4910-13-P
