AD 90-13-04

Final rule

90-13-04 SAAB-SCANIA: Amendment 39-6631. Docket No. 90-NM-16-AD.
Applicability: Model SF-340A series airplanes, Serial Numbers 004 through 108, inclusive, certificated in any category.

Compliance: Required prior to the accumulation of 16,000 landings or within 30 days after the effective date of this AD, whichever occurs later, unless previously accomplished.

To prevent fatigue damage and reduced structural integrity of the wings, accomplish the following:

A. Remove the four fasteners in the lower part of the wing/fuselage attachment fitting at Wing Station 42.3 (left and right wings), enlarge the holes, and inspect for cracks using a non-destructive testing method (eddy current), in accordance with SAAB-Scania Service Bulletin 340-57-017, dated December 1, 1989.

1. If no cracks are found, prior to further flight, install oversize fasteners in accordance with the service bulletin.

2. If cracks are found, prior to further flight, further enlarge theholes and install oversize fasteners, in accordance with the service bulletin. The holes may be enlarged up to 0.264/0.262 inch (6,706/6,655 mm).

3. If cracks are still found following the maximum reaming allowed, repair prior to further flight, in a manner approved by the Manager, Standardization Branch, ANM-113, FAA, Northwest Mountain Region.

B. An alternate means of compliance or adjustment of the compliance time, which provides an acceptable level of safety, may be used when approved by the Manager, Standardization Branch, ANM- 113, FAA, Northwest Mountain Region.

NOTE: The request should be forwarded through an FAA Principal Maintenance Inspector (PMI), who will either concur or comment and then send it to the Manager, Standardization Branch, ANM-113.

C. Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base in order to comply with the requirements of this AD.

All persons affected by this directivewho have not already received the appropriate service documents from the manufacturer may obtain copies upon request to SAAB-Scania, Product Support, S- 581.88, Linkoping, Sweden. These documents may be examined at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 17900 Pacific Highway South, Seattle, Washington, or the Standardization Branch, 9010 East Marginal Way South, Seattle, Washington.

This amendment (39-6631, AD 90-13-04) becomes effective on July 23, 1990.