[Federal Register: April 15, 2004 (Volume 69, Number 73)]
[Proposed Rules]
[Page 19956-19958]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr15ap04-18]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 2003-NM-235-AD]
RIN 2120-AA64
Airworthiness Directives; Short Brothers Model SD3-SHERPA Series
Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: This document proposes the adoption of a new airworthiness
directive (AD) that is applicable to certain Short Brothers Model SD3-
SHERPA series airplanes. This proposal would require a repetitive
detailed inspection of the stub wing shear decks for corrosion and
abnormal wear on and around the retaining pin in the main landing gear
(MLG) forward pintle pin; and corrective action, if necessary. This
proposed AD also provides an optional terminating action. These actions
are necessary to detect and correct corrosion and abnormal wear to the
top and bottom shear decks, which could result in damage to the MLG and
consequent reduced controllability of the airplane on landing. This
action is intended to address the identified unsafe condition.
DATES: Comments must be received by May 17, 2004.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 2003-NM-235-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-235-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
[[Page 19957]]
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-235-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-235-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 certain Short Brothers Model SD3-SHERPA series
airplanes. The CAA advises that a report has been received stating that
corrosion and abnormal wear to the top and bottom shear decks was found
on and around the retaining pin in the main landing gear (MLG) forward
pintle pin, due to loss of the retaining pin circlip, which allowed
migration of the retaining pin. This condition, if not corrected, could
result in damage to the MLG and consequent reduced controllability of
the airplane on landing.
Explanation of Relevant Service Information
Short Brothers has issued Short Brothers Service Bulletin SD3
SHERPA-53-6, dated May 2003, which describes procedures for repetitive
detailed inspections of the stub wing shear decks for corrosion and
abnormal wear on and around the retaining pin in the MLG forward pintle
pin; and corrective action, if necessary. The corrective action
involves blending out corrosion, installing bushings in the affected
shear deck, performing a visual inspection of the MLG pintle pin and
sleeve for defects, and repairing any defects, as applicable.
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 airworthiness
directive 004-05-2003, dated August 2003, to ensure the continued
airworthiness of these airplanes in the United Kingdom.
Short Brothers has also issued Service Bulletin SD3 SHERPA-32-4,
dated July 2003. That service bulletin describes procedures for
replacement of the retaining pin and circlip with a new retaining pin,
washer, castellated nut, and cotter pin, which would eliminate the need
for repetitive detailed inspections of that retaining pin.
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 Short Brothers Service Bulletin SD3 SHERPA-53-
6 described previously, except as discussed below.
Differences Among Proposed Rule, British Airworthiness Directive, and
Referenced Service Bulletin
Although Service Bulletin SD3 SHERPA-53-6 specifies that operators
may contact the manufacturer for disposition of certain corrective
actions, this proposal would require operators to perform those actions
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 (or its delegated
agent) would be acceptable for compliance with this proposed AD.
Operators should note that, although the referenced service
bulletin describes procedures for reporting inspection results to the
manufacturer, this proposed AD would not require that action. The FAA
does not need this information from operators.
Operators should note that the British airworthiness directive
specifies that initial inspection of the stub wing shear decks for
corrosion and abnormal wear on and around the retaining pin in the MLG
forward pintle pin should be accomplished no later than October 31,
2003 (which equates to a compliance time of 3 months after the
effective date of the British airworthiness directive). In developing
an appropriate compliance time for this proposed AD, the FAA considered
not only the safety implications and the CAA's recommendations, but
also the manufacturer's recommendations. In light of all of these
factors, the FAA finds that the initial inspection must be accomplished
within 6 months after the effective date of this AD, which represents
an appropriate interval of time allowable for affected airplanes to
[[Page 19958]]
continue to operate without compromising safety.
Cost Impact
The FAA estimates that 16 airplanes of U.S. registry would be
affected by this proposed AD, that it would take approximately 13 work
hours per airplane per inspection to accomplish the proposed repetitive
inspections, 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 $13,520, or $845 per airplane, per
inspection.
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.
If an operator chooses to accomplish the optional terminating
action rather than continue the repetitive detailed inspections, it
would take about 12 work hours per stub wing (2 stub wings per
airplane) to accomplish the replacement of the retaining pin and
circlip with a new retaining pin with castellated nut and cotter pin;
at an average labor rate of $65 per work hour. Required parts would
cost about $2,400 per stub wing. Based on these figures, we estimate
the cost of this optional terminating action to be $6,360 per airplane.
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-235-AD.
Applicability: Model SD3-SHERPA series airplanes, except those
which have embodied Short Brothers Service Bulletin SD3 SHERPA-32-4,
dated July 2003; certificated in any category.
Compliance: Required as indicated, unless accomplished
previously.
To detect and correct corrosion and abnormal wear to the top and
bottom shear decks, which could result in damage to the main landing
gear (MLG) and consequent reduced controllability of the airplane on
landing, accomplish the following:
Repetitive Inspections
(a) Within 6 months after the effective date of this AD, and
continuing at intervals not to exceed 6 months, perform a detailed
inspection of the stub wing shear decks to detect corrosion and/or
abnormal wear according to the Accomplishment Instructions of Short
Brothers Service Bulletin SD3 SHERPA-53-6, dated May 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.''
Repair
(b) If any corrosion and/or abnormal wear is discovered during
the inspection required by paragraph (a) of this AD, before further
flight, perform corrective actions in accordance with the
Accomplishment Instructions of Short Brothers Service Bulletin SD3
SHERPA-53-6, dated May 2003, Part B and/or Part C as applicable;
except where the service bulletin specifies that operators should
contact the manufacturer for disposition of certain repair
conditions, before further flight, repair those conditions per a
method approved by the Manager, International Branch, ANM116,
Transport Airplane Directorate, FAA; or the UK-CAA or its delegated
agent.
Optional Terminating Action
(c) Performance of the optional terminating action, which
includes replacement of the retaining pin and circlip with a new
retaining pin, washer, castellated nut and cotter pin per the
Accomplishment Instructions of Short Brothers Service Bulletin SD3
SHERPA-32-4, dated July 2003, terminates the requirement for
repetitive detailed inspections specified in paragraph (a) of this
AD.
No Reporting Requirement
(d) Operators should note that, although Short Brothers Service
Bulletin SD3 SHERPA-53-6, dated May 2003, describes procedures for
reporting inspection results to the manufacturer, this AD does not
require that action.
Alternative Methods of Compliance
(e) In accordance with 14 CFR 39.19, the Manager, International
Branch, ANM116, 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 004-05-2003, dated August 2003.
Issued in Renton, Washington, on April 1, 2004.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 04-8534 Filed 4-14-04; 8:45 am]
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