[Federal Register Volume 64, Number 193 (Wednesday, October 6, 1999)]
[Proposed Rules]
[Pages 54237-54238]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-26087]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 99-NM-223-AD]
RIN 2120-AA64
Airworthiness Directives; Short Brothers Model SD3-60 SHERPA,
SD3-SHERPA, and SD3-30 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 all Short Brothers Model SD3-60
SHERPA, SD3-SHERPA, and SD3-30 series airplanes. This proposal would
require replacement of existing oxygen system ``O'' rings with improved
wear-resistant ``O'' rings. 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 prevent the loss of oxygen from the aircraft oxygen system,
which could result in an insufficient supply of oxygen being provided
to the airplane flight crew and passengers in the event of an
emergency.
DATES: Comments must be received by November 5, 1999.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 99-NM-223-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, 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 99-NM-223-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. 99-NM-223-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
The Civil Aviation Authority (CAA), which is the airworthiness
authority for the United Kingdom, recently notified the FAA that an
unsafe condition may exist on all Short Brothers Model SD3-60 SHERPA,
SD3-SHERPA, and SD3-30 series airplanes. The CAA advises that service
experience has shown that certain ``O'' rings of the airplane oxygen
system are prone to unexpected deterioration. This condition, if not
corrected, could result in an insufficient supply of oxygen being
provided to the airplane flight crew and passengers in the event of an
emergency.
Explanation of Relevant Service Information
Short Brothers has issued Service Bulletins SD360 Sherpa-35-2,
dated February 25, 1999 (for Model SD3-60 Sherpa series airplanes); SD3
Sherpa-35-3, Revision 1, dated May 5, 1999 (for
[[Page 54238]]
Model SD3 Sherpa series airplanes); and SD330-35-1, dated February 25,
1999 (for Model SD3-30 series airplanes). These service bulletins
describe procedures for replacement of existing oxygen system ``O''
rings with improved wear-resistant ``O'' rings. Accomplishment of the
actions specified in the service bulletins is intended to adequately
address the identified unsafe condition. The CAA classified these
service bulletins as mandatory and issued British airworthiness
directives 007-02-99 (for Model SD3-60 Sherpa series airplanes), 006-
02-99 (for Model SD3 Sherpa series airplanes), and 008-02-99 (for Model
SD3-30 series airplanes), in order to assure the continued
airworthiness of these airplanes in the United Kingdom.
FAA's Conclusions
These airplane models are manufactured in the United Kingdom and
are 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 bulletins described previously.
Cost Impact
The FAA estimates that 62 airplanes of U.S. registry would be
affected by this proposed AD, that it would take approximately 50 work
hours per airplane to accomplish the proposed actions, and that the
average labor rate is $60 per work hour. Required parts would be
provided by the manufacturer at no cost to operators. Based on these
figures, the cost impact of the proposed AD on U.S. operators is
estimated to be $186,000, or $3,000 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 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.
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 99-NM-223-AD.
Applicability: All Model SD3-60 SHERPA, SD3-SHERPA, and SD3-30
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 (c) 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 the loss of oxygen from the aircraft oxygen system,
accomplish the following:
(a) Within 24 months after the effective date of this AD,
replace oxygen system ``O'' rings, part number (P/N) MS28778, with
improved wear-resistant ``O'' rings, P/N MS9068, in accordance with
Shorts Service Bulletins SD360 Sherpa-35-2, dated February 25, 1999
(for Model SD3-60 Sherpa series airplanes); SD3 Sherpa-35-3,
Revision 1, dated May 5, 1999 (for Model SD3 Sherpa series
airplanes), and SD330-35-1, dated February 25, 1999 (for Model SD3-
30 series airplanes); as applicable.
(b) As of the effective date of this AD, no person shall install
an oxygen system ``O'' ring, P/N MS28778, on any airplane.
Alternative Methods of Compliance
(c) 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, FAA,
Transport Airplane Directorate. 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.
Special Flight Permits
(d) 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 directives 007-02-99 (for Model SD3-60 Sherpa series
airplanes), 006-02-99 (for Model SD3 Sherpa series airplanes), and
008-02-99 (for Model SD3-30 series airplanes).
Issued in Renton, Washington, on September 30, 1999.
D. L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 99-26087 Filed 10-5-99; 8:45 am]
BILLING CODE 4910-13-P
