98-11-26 SAAB AIRCRAFT AB: Amendment 39-10551. Docket 97-NM-134-AD.
Applicability: Model SAAB 340B series airplanes, serial numbers 240 through 430 inclusive; Model SAAB 2000 series airplanes, serial numbers 002 through 050 inclusive, and 052; 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 failure of the check valves, which could result in loss of airfoil de-icing capability during single engine operation, and consequent reduced controllability of the airplane, accomplish the following:
(a) Within 5 months after the effective date of this AD, modify the left- and right-hand check valves of the airfoil de-icing system, or replace the check valves with improved valves, in accordance with Saab Service Bulletin 340-30-080, dated November 21, 1997 (for Model SAAB 340B series airplanes), or Saab Service Bulletin 2000-30-012, dated November 21, 1997 (for Model SAAB 2000 series airplanes), as applicable.
(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 actions shall be done in accordance with Saab Service Bulletin 340-30-080, dated November 21, 1997, or Saab Service Bulletin 2000-30-012, dated November 21, 1997, as applicable. 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.
NOTE 3: The subject of this AD is addressed in Swedish airworthiness directive SAD No. 1-120, dated November 24, 1997.
(e) This amendment becomes effective on July 8, 1998.