90-06-09 BOEING: Amendment 39-6488. Docket No. 89-NM-60-AD. \n\n\tApplicability: Model 727 series airplanes, listed in Boeing Document No. D6-54860, Revision C, dated December 11, 1989, certificated in any category. \n\n\tCompliance: Required as indicated, unless previously accomplished. \n\n\tTo prevent structural failure, accomplish the following: \n\n\tA.\tExcept as provided below, prior to reaching the incorporation thresholds listed in Boeing Document No. D6-54860, Revision C, dated December 11, 1989, "Aging Airplane Service Bulletin Structural Modification Program - Model 727" (hereinafter called "the Document"), or within the next 4 years after the effective date of this AD, whichever occurs later, accomplish the structural modifications listed in Section 3 of the Document. Modifications for which the incorporation threshold is identified in the Document as a specific date must be accomplished by that date in lieu of the 4 years specified in this paragraph. \n\n\tNOTE: The modifications required by this paragraph do not terminate the inspection requirements of any other AD unless that AD specified that any such modification constitutes terminating action of the inspection requirements.\n \n\tB.\tAn 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, Seattle Aircraft Certification Office, FAA, Northwest Mountain Region. \n\n\tNOTE: 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, Seattle Aircraft Certification Office. \n\n\tC.\tSpecial 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. \n\n\tThe modifications shall be done in accordance with Boeing Document D6-54860, Revision C, dated December 11, 1989, "Aging Airplane Service Bulletin Structural Modification Program - Model 727." 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 Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124. Copies may be inspected at the FAA, Northwest Mountain Region, 17900 Pacific Highway South, Seattle, Washington; or at the Seattle Aircraft Certification Office, FAA, Northwest Mountain Region, 9010 East Marginal Way South, Seattle, Washington; or at the Office of the Federal Register, 1100 L Street, N.W., Room 8301, Washington, D.C. \n\n\tThis amendment (39-6488, AD 90-06-09) becomes effective on April 17, 1990.