AD 92-22-13

92-22-13 SAAB-SCANIA: Amendment 39-8400. Docket No. 92-NM-122-AD. Applicability: Models SAAB SF340A and SAAB 340B series airplanes; as listed in SAAB Service Bulletin 340-57-020, Revision 1, dated April 3, 1992; certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent the reduction of strength of the wing upper panel and possible fuel leakage, accomplish the following:

(a) Within 6 months after the effective date of this AD, perform a visual inspection for corrosion on the wing upper panel in the fuel tank access door area, in accordance with SAAB Service Bulletin 340-57-020, Revision 1, dated April 3, 1992.

(1) If corrosion is detected, prior to further flight, blend or grind it out, and measure the thickness of the blended or ground part, in accordance with the service bulletin.

(i) If the thickness of the blended or ground part is within the tolerances specified in the service bulletin, apply surface treatments in accordance with the service bulletin.

(ii) If the blended or ground part is outside the tolerances specified in the service bulletin, prior to further flight, repair in a manner approved by the Manager, Standardization Branch, ANM-113, FAA, Transport Airplane Directorate.

(2) If corrosion is not found, apply surface treatments in accordance with the service bulletin.

(b) Within 6 months after accomplishing paragraph (a) of this AD, perform a second visual inspection to detect corrosion on the wing upper panel in the fuel tank access door area, in accordance with SAAB Service Bulletin 340-57-020, Revision 1, dated April 3, 1992.

(1) If corrosion is detected, prior to further flight, blend or grind it out, and measure the thickness of the blended or ground part, in accordance with the service bulletin.

(i) If the thickness of the blended or ground part is within the tolerances specified in the service bulletin, apply surface treatments in accordance with the service bulletin.

(ii) If the blended or ground part is outside the tolerances specified in the service bulletin, prior to further flight, repair in a manner approved by the Manager, Standardization Branch, ANM-113, FAA, Transport Airplane Directorate.

(2) If corrosion is not found, apply surface treatments in accordance with the service bulletin.

(3) Following the visual inspection and repairs required by paragraph (b) of this AD, prior to further flight, install protection plates on all fuel tank access hole doublers, and apply surface treatments, in accordance with the service bulletin.

(c) Installation of protection plates on all fuel tank access hole doublers and application of surface treatments, in accordance with SAAB Service Bulletin 340-57-020, Revision 1, dated April 3, 1992, that is accomplished prior to further flight following the visual inspection required by paragraph (a) of this AD, constitutes terminating action for the visual inspection required by paragraph (b) 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: 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 FAR 21.197 and 21.199 to operate the airplane to a location where the requirements of this AD can be accomplished.

(f) The inspections, corrective actions, and the surface treatments shall be done in accordance with SAAB Service Bulletin 340-57-020, Revision 1, dated April 3, 1992, which contains the following list of effective pages:

Page Number Revision Level Shown on Page Date Shown on Page 1-5, 8-18 Original (Not Dated) 6-7, 19-20 1 April 3, 1992

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-SCANIA AB, SAAB Aircraft Product Support, S-581 88, Linkoping, 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 December 3, 1992.