80-19-05 BOEING: Amendment 39-3906. Applies to all Model 747 series airplanes, unless already accomplished: \n\n\tWithin the next 24 months from the effective date of this AD, modify the leading edge flap systems in accordance with Boeing Service Bulletin No. 747-27-2204, dated April 25, 1980, or a later FAA-approved service bulletin, or in a manner approved by the Chief, Engineering and Manufacturing Branch, Northwest Region.\n \n\tThe manufacturer's specifications and procedures identified and described in this directive are incorporated herein and made a part hereof pursuant to 5 U.S.C. 552(a)(1). All persons affected by this directive who have not already received these documents from the manufacturer may obtain copies upon request to Boeing Commercial Airplane Company, P.O. Box 3707, Seattle, Washington 98124. These documents may also be examined at FAA, Northwest Region, 9010 East Marginal Way South, Seattle, Washington 98108. \n\n\tThis amendment becomes effective October 9,1980.