90-17-13 FOKKER: Amendment 39-6697. Docket No. 90-NM-65-AD.
Applicability: Model F-27 series airplanes, Serial Numbers 10102 and 10105 through 10624, inclusive, certificated in any category.
Compliance: Required as indicated, unless previously accomplished.
To prevent reduced structural integrity of the wing, accomplish the following:
A. Within 180 days after the effective date of this AD, perform a high frequency eddy current (HFEC) inspection of the fork-end fittings of the wing upper skin stringers at the outboard side of the Wing Station 4155 joint, in accordance with Fokker Service Bulletin F27/57-64, Revision 1, dated March 28, 1990.
B. If cracks are found in the lower part of the fillet radius, prior to further flight, blend until there is no crack indication, but do not exceed a maximum depth of 2.5 mm, in accordance with Fokker Service Bulletin F27/57-64, Revision 1, dated March 28, 1990. If the crack is still present after maximum blending, theaffected coupling rods must be replaced prior to further flight.
C. If cracks are found in the upper part of the fillet radius, replace the affected coupling rods, prior to further flight, in accordance with Fokker Service Bulletin F27/57-64, Revision 1, dated March 28, 1990.
D. 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, Transport Airplane Directorate.
NOTE: The request should be submitted directly to the Manager, Standardization Branch, ANM- 113, and a copy sent to the cognizant FAA Principal Inspector (PI). The PI will then forward comments or concurrence to the Manager, Standardization Branch, ANM-113.
E. 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 directive who have not already received the appropriate service documents from the manufacturer may obtain copies upon request to Fokker Aircraft USA, Inc., 1199 N. Fairfax Street, Alexandria, Virginia 22314. These documents may be examined at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 1601 Lind Avenue, S.W., Renton, Washington.
This amendment (39-6697, AD 90-17-13) becomes effective on September 17, 1990.