AD 2000-12-07 Airworthiness Directives; Saab Model SAAB SF340A and SAAB 340B Series Airplanes

Model SAAB SF340A, serial numbers -004 through -159 inclusive; and SAAB 340B series airplanes, serial numbers -160 through -444 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 (d) 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.

Required as indicated, unless accomplished previously. To prevent corrosion in the inboard and outboard bearing housings of the support assembly of the main landing gear (MLG), which could result in fatigue cracks in the support assembly and lead to failure of the MLG, accomplish the following: Initial Inspection (a) At the applicable time specified in paragraph (a)(1), (a)(2), (a)(3), or (a)(4) of this AD: Perform a one-time general visual inspection of the eight bearing housing surfaces of the MLG to detect corrosion or scratches, in accordance with Saab Service Bulletin 340-57-036, dated October 20, 1999. (1) For airplanes with 32,000 or more total flight cycles as of the effective date of this AD, the inspection is to be performed within 4,000 flight cycles after the effective date of this AD. (2) For airplanes with 24,000 or more and fewer than 32,000 total flight cycles as of the effective date of this AD, the inspection is to be performed within 6,000 flight cycles after the effective date of this AD. (3) For airplanes with 12,000 or more and fewer than 24,000 total flight cycles as of the effective date of this AD, the inspection is to be performed prior to the accumulation of 24,000 total flight cycles, or within 6,000 flight cycles after the effective date of this AD, whichever occurs later. (4) For airplanes with fewer than 12,000 total flight cycles as of the effective date of this AD, the inspection is to be performed prior to the accumulation of 12,000 total flight cycles, or within 6,000 flight cycles after the effective date of this AD, whichever occurs later. Note 2: For the purposes of this AD, a general visual inspection is defined as: “A visual examination of an interior or exterior area, installation, or assembly to detect obvious damage, failure, or irregularity. This level of inspection is made under normally 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.” Corrective Actions (b) Except as provided by paragraph (c) of this AD: If, during the inspection required by paragraph (a) of this AD, any corrosion or scratch is detected that is within the limits specified in Saab Service Bulletin 340-57-036, dated October 20, 1999, prior to further flight, perform corrective actions (including rework, an eddy current inspection, and repair) in accordance with Steps 2.B. and 2.C. of the Accomplishment Instructions of the service bulletin. (1) If, after rework, the depth of the damage is less than or equal to 0.15 mm (0.006 inches) AND the damage does not exceed 15 percent of the area, no further action is required by this AD. (2) If, after rework, the depth of the damage exceeds 0.15 mm (0.006 inches) but is less than or equal to 1.1 mm (0.043 inches), AND the damage does not exceed 30 percent of the area: Within 4,000 flight cycles after accomplishment of the inspection required by paragraph (a), repair the MLG support assembly in accordance with the service bulletin. Following the repair, no further action is required by this AD. (c) If, during any inspection required by this AD, a discrepancy is detected for which the service bulletin specifies to contact Saab for appropriate action [including any crack or any corrosion or scratch that exceeds 1.1 mm (0.043 in) after applicable rework has been performed as required by paragraph (b) of this AD]: Prior to further flight, repair in accordance with a method approved by the Manager, International Branch, ANM-116, Transport Airplane Directorate; or the Luftfartsverket (LFV) (or its delegated agent). For a repair method to be approved by the Manager, International Branch, ANM-116, as required by this paragraph, the Manager's approval letter must specifically reference this AD. Alternative Methods of Compliance (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, 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 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the International Branch, ANM-116. Special Flight Permits (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. Incorporation by Reference (f) Except as specified by paragraph (c) of this AD, the inspections and corrective actions shall be done in accordance with Saab Service Bulletin 340-57-036, dated October 20, 1999. 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, Linköping, 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 4: The subject of this AD is addressed in Swedish airworthiness directive 1-146, dated October 20, 1999. (g) This amendment becomes effective on July 20, 2000. Issued in Renton, Washington, on June 7, 2000. Donald L. Riggin, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 00-14951 Filed 6-14-00; 8:45 am] BILLING CODE 4910-13-U