[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