[Federal Register Volume 64, Number 167 (Monday, August 30, 1999)]
[Proposed Rules]
[Pages 47146-47148]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-22391]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 99-NM-199-AD]
RIN 2120-AA64
Airworthiness Directives; Saab Model SAAB SF340A and 340B 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 Saab Model SAAB SF340A and
340B series airplanes. This proposal would require removal of certain
main landing gear downlock and brake hydraulic swivel brackets and
replacement with new, redesigned brackets. 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 failure of the downlock or brake swivels. Brake
swivel failure could cause the loss of inboard or outboard brakes.
Downlock swivel failure could cause the loss of hydraulic fluid in the
main hydraulic system, as well as the loss of nose wheel steering
operation, extension and retraction capability of landing gear and
flaps, and operation of the propeller brake (if installed).
DATES: Comments must be received by September 29, 1999.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 99-NM-199-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 Saab Aircraft AB, SAAB Aircraft Product Support, S-
581.88, Linkoping, Sweden. 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-199-AD.'' The postcard will be date stamped and
returned to the commenter.
[[Page 47147]]
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-199-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
The Luftfartsverket (LFV), which is the airworthiness authority for
Sweden, notified the FAA that an unsafe condition may exist on certain
Saab Model SAAB SF340A and 340B series airplanes. The LFV advises that
a misalignment of the downlock or brake hydraulic swivels in the main
landing gear (MLG) dragbrace and MLG shock strut trunnions has, due to
excessive loads during extension/retraction of landing gear, resulted
in an abnormally high failure rate of the hydraulic swivels. Brake
swivel failure could cause the loss of inboard or outboard brakes.
Downlock swivel failure could cause the loss of hydraulic fluid in the
main system, as well as the loss of nose wheel steering operation,
extension and retraction of landing gear and flaps, and operation of
the propeller brake (if installed).
Explanation of Relevant Service Information
Saab Aircraft AB has issued Service Bulletin 340-29-009, Revision
02, dated July 2, 1999, which describes procedures for removal of
certain main landing gear downlock and brake swivel brackets and
replacement with new, redesigned brackets. Accomplishment of the
actions specified in the service bulletin is intended to adequately
address the identified unsafe condition. The LFV classified this
service bulletin as mandatory and issued Swedish airworthiness
directive SAD No. 1-145, dated July 2, 1999, in order to assure the
continued airworthiness of these airplanes in Sweden.
FAA's Conclusions
These airplane models are manufactured in Sweden 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 LFV has kept the FAA informed of
the situation described above. The FAA has examined the findings of the
LFV, 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.
Cost Impact
The FAA estimates that 200 airplanes of U.S. registry would be
affected by this proposed AD, that it would take approximately 2 work
hours per airplane to accomplish the proposed replacement, and that the
average labor rate is $60 per work hour. Required parts would cost
approximately $1,375 per airplane. Based on these figures, the cost
impact of the proposed AD on U.S. operators is estimated to be
$299,000, or $1,495 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:
SAAB Aircraft AB: Docket 99-NM-199-AD.
Applicability: Model SAAB SF340A series airplanes, serial
numbers SF340A-004 through -159 inclusive, and Model SAAB 340B
series airplanes, serial numbers SF340B-160 through -339 inclusive;
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 (b) 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 failure of the main landing gear (MLG) downlock or
brake hydraulic swivels and consequent loss of certain hyraulic-
powered operations, accomplish the following:
Bracket Replacement
(a) Within 12 months after the effective date of this AD, remove
the MLG downlock and brake hydraulic swivel brackets and replace
with new, improved parts, in accordance with Saab Service Bulletin
340-29-009, Revision 02, dated July 2, 1999.
Note 2: Accomplishment, prior to the effective date of this AD,
of the bracket replacement in accordance with Saab Service Bulletin
340-29-009, dated August 20, 1992, or Revision 1, dated April 15,
1993, is considered acceptable for compliance with the requirements
of paragraph (a) of this AD.
Alternative Methods of Compliance
(b) 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
[[Page 47148]]
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 3: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Manager, International Branch, ANM-116.
Special Flight Permits
(c) 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 4: The subject of this AD is addressed in Swedish
airworthiness directive SAD No. 1-145, dated July 2, 1999.
Issued in Renton, Washington, on August 23, 1999.
Vi L. Lipski,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 99-22391 Filed 8-27-99; 8:45 am]
BILLING CODE 4910-13-P