AD 95-22-05 ACTIVE

This amendment adopts a new airworthiness directive (AD) that is applicable to certain Saab Model SAAB SF340A and SAAB 340B series airplanes. This action requires repetitive inspections to detect damage of the brake assembly and wheel assembly; repair, if necessary; and installation of a heat shield. This action also provides for an optional installation which, if accomplished, constitutes terminating action for the repetitive inspections. This amendment is prompted by reports of failure of the brake assembly due to separation of the stator clips from the stator disk. The actions specified in this AD are intended to prevent failure of the brake assembly, which could result in a brake fire.

Final rule; request for comments.

95-22-05 SAAB AIRCRAFT AB: Amendment 39-9412. Docket 95-NM-187-AD.
Applicability: Model SAAB SF340A series airplanes having serial numbers 004 through 159, inclusive; and Model SAAB 340B series airplanes having serial numbers 160 and subsequent; equipped with brake assemblies having part number 5012589, 5007219-1, 5008541, 5008541-1, or 5008541-2; certificated in any category.
NOTE 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been otherwise 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 use the authority provided in paragraph (d) of this AD to request approval from the FAA. This approval may address either no action, if the current configuration eliminates the unsafe condition; or different actions necessary to address the unsafe condition described in this AD. Such a request should include an assessment of the effect of the changed configuration on the unsafe condition addressed by this AD. In no case does the presence of any modification, alteration, or repair remove any airplane from the applicability of this AD.
Compliance: Required as indicated, unless accomplished previously.
To prevent failure of the brake assembly and wheel assembly, which could result in the potential for a brake fire, accomplish the following:
(a) Within 10 days after the effective date of this AD, perform a visual inspection to detect damage of the brake assembly and wheel assembly in accordance with Saab Service Bulletin 340-32-105, dated September 5, 1995.
(1) If no damage is detected, repeat the inspection thereafter at intervals not to exceed 225 hours time-in-service.
(2) If any damage is detected, prior to further flight, repair the damaged brake assembly and/or wheel assembly in accordance with the service bulletin. Repeat the inspection thereafter at intervals not to exceed 225 hours time-in-service.
(b) Within 225 hours time-in-service after accomplishing the inspection required by paragraph (a) of this AD, install a heat shield in the torque tube in accordance with Saab Service Bulletin 340-32-105, dated September 5, 1995.
(c) Installation of a redesigned stator clip in accordance with a method approved by the Manager, Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, constitutes terminating action for the repetitive inspections required by paragraph (a) of this AD.
(d) 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, Standardization Branch, ANM-113, 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, Standardization Branch, ANM-113.
NOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Standardization Branch, ANM-113.
(e) 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.
(f) The inspections, repair, and installation of a heat shield shall be done in accordance with Saab Service Bulletin 340-32-105, dated September 5, 1995. 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, Link 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.
(g) This amendment becomes effective on November 8, 1995.

The Luftfartsverket (LFV), which is the airworthiness authority for Sweden, recently notified the FAA that an unsafe condition may exist on certain Saab Model SAAB SF340A and SAAB 340B series airplanes. The LFV advises that it has received several reports indicating that the brake assembly failed on several of these airplanes. Investigation revealed that the cause of the failures of the brake assemblies was due to separation of the stator clips from the stator disk. (The stator clip is a steel component that attaches to the stator lug to offer better resistance to damage of the drive face of the lug.) Brake assemblies having part numbers 5012589, 5007219-1, 5008541, 5008541-1, and 5008541-2 have been identified as those susceptible to such failure.
In certain reported instances, these separated clips migrated through the torque tube lightening hole and became trapped between the torque tube and the wheel hub. In at least one case, this resulted in acut through the hub, leakage of hydraulic fluid on the hot brakes, and subsequent brake fire fueled by hydraulic fluid. In other reported incidents, the separated clips migrated through the carbon stack and resulted in brake damage or disintegration.
These conditions, if not detected, could result in brake and wheel failure, which could lead to a brake fire.
Saab has issued Service Bulletin 340-32-105, dated September 5, 1995, which describes procedures for repetitive visual inspections to detect damage of the brake assembly and wheel assembly, repair of damaged assemblies, and installation of a heat shield in the torque tube. The LFV classified this service bulletin as mandatory and issued Swedish airworthiness directive SAD 1-075, dated September 7, 1995, in order to assure the continued airworthiness of these airplanes in Sweden.
This airplane model is manufactured in Sweden and is type certificated for operation in the United States under the provisions of section 21.29of 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.
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 failure of the brake assembly, which could result in a brake fire. This AD requires repetitive visual inspections to detect damage of the brake assembly and wheel assembly, repair of any damaged brake assembly or wheel assembly found, and installation of a heat shield. The actions are required to be accomplished in accordance with the service bulletin described previously.
This AD also provides for termination of the repetitive visual inspections by installing a redesigned stator clip. This installation is to be accomplished in accordance with a method approved by the FAA.
This is considered to be interim action. The manufacturer has advised that it is currently developing a modified stator clip that will positively address the unsafe condition addressed by this AD. Once this redesigned clip is developed, approved, and available, the FAA may consider additional rulemaking.
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 reportthat summarizes each FAA-public contact concerned with the substance of this AD will be filed in 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 95-NM-187-AD." The postcard will be date stamped and returned to the commenter.
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 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
1. The authority citation forpart 39 continues to read as follows: Authority: 49 USC 106(g), 40101, 40113, 44701. 39.13 - [Amended]
2. Section 39.13 is amended by adding the following new airworthiness directive:

Submit comments in triplicate to the Federal Aviation Administration (FAA),
Transport Airplane Directorate, ANM-103, Attention: Rules Docket No. 95-NM-187-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, Link ping, 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.

Ruth E. Harder, Aerospace Engineer, Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206) 227-1721; fax (206) 227-1149.