AD 2005-04-12

The FAA is adopting a new airworthiness directive (AD) for certain Saab Model SAAB SF340A and SAAB 340B series airplanes. This AD requires repetitive inspections for wear of the brushes and leads and for loose rivets of the direct current (DC) starter generator, and related investigative/corrective actions if necessary. This AD is prompted by reports of premature failures of the DC starter generator prior to scheduled overhaul. We are issuing this AD to prevent failure of the starter generator, which could cause a low voltage situation in flight and result in increased pilot workload and reduced redundancy of the electrical powered systems.

Final rule.

2005-04-12 SAAB Aircraft AB: Amendment 39-13984. Docket No. FAA- 2004-19752; Directorate Identifier 2004-NM-170-AD.

Effective Date

(a) This AD becomes effective April 1, 2005.

Applicability

(b) This AD applies to Saab Model SAAB SF340A series airplanes having serial numbers 004 through 159 inclusive, and Model SAAB 340B series airplanes having serial numbers 160 through 367 inclusive; certificated in any category; on which Saab Service Bulletin 340-24- 026 (Modification 2533) has not been implemented.

Unsafe Condition

(c) This AD was prompted by reports of premature failures of the direct current (DC) starter generator prior to scheduled overhaul. We are issuing this AD to prevent failure of the starter generator, which could cause a low voltage situation in flight and result in increased pilot workload and reduced redundancy of the electrical powered systems.

Compliance

(d) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.

Inspections for Wear of the DC Starter Generator Brushes and Leads

(e) For generators overhauled in accordance with Maintenance Review Board (MRB) Task 243104: Before 800 flight hours since the last overhaul or within 100 flight hours after the effective date of this AD, whichever occurs later, perform a general visual inspection for wear of the DC starter generator brushes and leads, in accordance with Saab Service Bulletin 340-24-035, dated July 5, 2004.

Note 1: For the purposes of this AD, a general visual inspection is "a visual examination of a interior or exterior area, installation or assembly to detect obvious damage, failure or irregularity. This level of inspection is made from within touching distance unless otherwise specified. A mirror may be necessary to ensure visual access to all surfaces in the inspection area. This level of inspection is made under normal available lightingconditions such as daylight, hangar lighting, flashlight or drop- light and may require removal or opening of access panels or doors. Stands, ladders or platforms may be required to gain proximity to the area being checked."

Note 2: Saab Service Bulletin 340-24-035, dated July 5, 2004, references Goodrich Service Information Letter 23080-03X-24-01, dated July 1, 2004, as an additional source of service information.

(1) If the tops of the brush sets are above the top of the brush box, repeat the inspection at intervals not to exceed 800 flight hours.

(2) If the tops of the brush sets are below the top of the brush box, before further flight, measure the brushes and determine the remaining amount of brush life remaining, in accordance with the service bulletin.

(i) If the brush wear is within the limits specified in the service bulletin, repeat the inspection at intervals not to exceed 800 flight hours.

(ii) If the brush wear is outside the limits specified in the service bulletin, before further flight, replace the starter generator with a new or serviceable starter generator, in accordance with the service bulletin.

Inspections for Loose Rivets

(f) For generators overhauled in accordance with MRB Task 243104: Before 800 flight hours since last overhaul or within 100 flight hours after the effective date of this AD, whichever occurs later, perform a general visual inspection of each leading wafer brush for loose rivets, in accordance with Saab Service Bulletin 340-24-035, dated July 5, 2004. Repeat the inspections at intervals not to exceed 800 flight hours. If any rivet is loose, before further flight, replace the DC starter generator with a new or serviceable starter generator, in accordance with the service bulletin.

MRB Task 243103 or 243101

(g) For generators overhauled or with brush replacement accomplished in accordance with MRB Task 243103 or 243101, no action is required by this AD.

Alternative Methods of Compliance (AMOCs)

(h) The Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate, FAA, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19.

Related Information

(i) Swedish airworthiness directive 1-196 R1, effective July 15, 2004, also addresses the subject of this AD.

Material Incorporated by Reference

(j) You must use Saab Service Bulletin 340-24-035, dated July 5, 2004, including Attachment 1 (Goodrich Service Information Letter 23080-03X-24-01), dated July 1, 2004, to perform the actions that are required by this AD, unless the AD specifies otherwise. The Director of the Federal Register approves the incorporation by reference of this document in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. For copies of the service information, contact Saab Aircraft AB, SAAB Aircraft Product Support, S-581.88, Linkoping, Sweden. For information on the availability of this material at the National Archives and Records Administration (NARA), call (202) 741-6030, or go to
http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html. You may view the AD docket at the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street SW., room PL-401, Nassif Building, Washington, DC.

The FAA proposed to amend 14 CFR Part 39 with an AD for certain Saab Model SAAB SF340A and SAAB 340B series airplanes. That action, published in the Federal Register on December 1, 2004 (69 FR 69836), proposed to require repetitive inspections for wear of the brushes and leads and for loose rivets of the direct current starter generator, and related investigative/corrective actions if necessary.

Comments

We provided the public the opportunity to participate in the development of this AD. No comments have been submitted on the proposed AD or on the determination of the cost to the public.

Conclusion

We have carefully reviewed the available data and determined that air safety and the public interest require adopting the AD as proposed.

Interim Action

This is considered to be interim action until final action is identified, at which time we may consider further rulemaking.

Costs of Compliance

This AD will affect about 170 airplanes of U.S. registry. The required actions will take about 1 work hour per airplane, at an average labor rate of $65 per work hour. Based on these figures, the estimated cost of the AD for U.S. operators is $11,050, per inspection cycle, or $65 per airplane, per inspection cycle.

Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, Section 106, describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the Agency's authority.

We are issuing this rulemaking under the authority described in Subtitle VII, Part A, Subpart III, Section 44701, "General requirements." Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.

Regulatory Findings

We have determined that this AD will not have federalism implications under Executive Order 13132. This AD will not have a substantial direct effect 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.

For the reasons discussed above, I certify that this AD:

(1) Is not a "significant regulatory action" under Executive Order 12866;

(2) Is not a "significant rule" under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and

(3) 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.

We prepared a regulatory evaluation of the estimated costs to comply with this AD. See the ADDRESSES section for a location to examine the regulatory evaluation.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.

Adoption of the Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA amends 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.

39.13 [Amended]

2. The FAA amends 39.13 by adding the following new airworthiness directive (AD):