AD 2005-04-12 Airworthiness Directives; Saab Model SAAB SF340A and SAAB 340B Series Airplanes

Models named: SAAB SF340A series, SAAB 340B series. Read the applicability below — it usually turns on serial or part numbers too.

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.

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 lighting conditions 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, Linköping, 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. Issued in Renton, Washington, on February 11, 2005. Kalene C. Yanamura, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 05-3281 Filed 2-24-05; 8:45 am] BILLING CODE 4910-13-P

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.