Airworthiness directives: Saab,
[Federal Register: October 2, 1998 (Volume 63, Number 191)]
[Rules and Regulations]
[Page 52961-52963]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr02oc98-3]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-NM-287-AD; Amendment 39-10816; AD 98-21-08]
RIN 2120-AA64
Airworthiness Directives; Saab Model SAAB 2000 Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule; request for comments.
SUMMARY: This amendment adopts a new airworthiness directive (AD) that is applicable to certain Saab Model SAAB 2000 series airplanes. This action requires repetitive functional tests (checks) to verify proper operation of the nose wheel steering system (NWSS) limitswitch, and replacement of the existing limitswitch with a new limitswitch, if necessary. This amendment is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified in this AD are intended to prevent combined failure of the limitswitch and the feedback shaft in the NWSS servo unit, which could result in uncommanded nose wheel steering deflection and reduced controllability of the airplane on the ground during takeoff or landing.
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DATES: Effective October 19, 1998.
The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of October 19, 1998.
Comments for inclusion in the Rules Docket must be received on or before November 2, 1998.
ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 98-NM-287-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.
The service information referenced in this AD 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; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.
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: The Luftfartsverket (LFV), which is the airworthiness authority for Sweden, notified the FAA that an unsafe condition may exist on certain Saab Model SAAB 2000 series airplanes. The LFV advises that it received a report of uncommanded nose wheel steering deflection during landing of a Saab Model SAAB 2000 series airplane, without pilot engagement of the steering system. This deflection was attributed to a short circuit in the nose wheel steering system (NWSS) limitswitch, in combination with a failure of the feedback shaft in the NWSS servo unit. The LFV also advised the FAA that previous failures of the feedback shaft have been reported and corrective action for the NWSS servo units is presently being evaluated. Such combined failure of the limitswitch and the feedback shaft could result in uncommanded nose wheel steering deflection and reduced controllability of the airplane on the ground during takeoff or landing.
Explanation of Relevant Service Information
Saab has issued Service Bulletin 2000-32-050, dated August 24, 1998, which describes procedures for repetitive functional tests (checks) to verify proper operation of the NWSS limitswitch, and replacement of the limitswitch, if necessary. The LFV classified this service bulletin as mandatory and issued Swedish airworthiness directive SAD 1-130, dated August 27, 1998, in order to assure the continued airworthiness of these airplanes in Sweden.
FAA's Conclusions
This airplane model is manufactured in Sweden 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 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 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, this AD is being issued to prevent combined failure of the limitswitch and the feedback shaft of the NWSS, which could result in reduced controllability of the airplane on the ground during takeoff or landing. This AD requires accomplishment of the actions specified in the service bulletin described previously.
Interim Action
The FAA is considering further rulemaking action to supersede this AD to require modification of the feedback shaft in the NWSS servo units, which will constitute terminating action for the repetitive functional tests (checks) required by this AD action. However, the planned compliance time for these actions is sufficiently long so that prior notice and time for public comment will be practicable.
Determination of Rule's Effective Date
Since a situation exists that requires the immediate adoption of this regulation, it is found that notice and opportunity for prior public comment hereon are impracticable, and that good cause exists for making this amendment effective in less than 30 days.
Comments Invited
Although this action is in the form of a final rule that involves requirements affecting flight safety and, thus, was not preceded by notice and an opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this 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 under the caption ADDRESSES. All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed.
Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the 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 that summarizes each FAA-public contact concerned with the substance of this AD will be filedin the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this rule must submit a self-addressed, stamped postcard on which the following statement is made: ``Comments to Docket Number 98-NM-287-AD.'' The postcard will be date stamped and returned to the commenter.
Regulatory Impact
The regulations adopted herein will 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 final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.
The FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and that it is not a ``significant regulatory action'' under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory
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Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket. A copy of it, if filed, may be obtained from the Rules Docket at the location provided under the caption ADDRESSES.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.
Adoption of the Amendment
Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:
PART 39--AIRWORTHINESS DIRECTIVES
-
The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
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Section 39.13 is amended by adding the following new airworthiness directive:
98-21-08 Saab Aircraft AB: Amendment 39-10816. Docket 98-NM-287-AD.
Applicability: Model SAAB 2000 series airplanes, serial numbers 004 through 063 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 combined failure of the limitswitch and the feedback shaft in the nose wheel steering system (NWSS) servo unit, which could result in uncommanded nose wheel steering deflection and reduced controllability of the airplane on the ground during takeoff or landing, accomplish the following:
(a) Within 3 weeks after the effective date of this AD, perform a functional test (check) to verify proper operation of the NWSS limitswitch, in accordance with Saab Service Bulletin 2000-32-050, dated August 24, 1998.
(1) If no malfunction is detected, repeat the functional test thereafter at intervals not to exceed 400 flight hours.
(2) If any malfunction is detected, prior to further flight, replace the existing limitswitch with a new limitswitch in accordance with the service bulletin. Repeat the functional test thereafter at intervals not to exceed 400 flight hours.
(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 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.
(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.
(d) The functional tests (checks) and replacement shall be done in accordance with Saab Service Bulletin 2000-32-050, dated August 24, 1998. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Saab Aircraft AB, SAAB Aircraft Product Support, S-581.88, Linko-ping, Sweden. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.
Note 3: The subject of this AD is addressed in Swedish airworthiness directive SAD 1-130, dated August 27, 1998.
(e) This amendment becomes effective on October 19, 1998.
Issued in Renton, Washington, on September 28, 1998. Darrell M. Pederson, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.
[FR Doc. 98-26389Filed10-1-98; 8:45 am]
BILLING CODE 4910-13-P
