91-07-19 BOEING: Amendment 39-6926. Docket No. 89-NM-263-AD. \n\n\tApplicability: Model 707/720 series airplanes, listed in Boeing Document No. D6-54996, Revision B, dated December 11, 1990, 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.\tAccomplish the structural modifications listed in Section 3 of Boeing Document No. D6- 54996, "Aging Airplane Service Bulletin Structural Modification Program-Model 707/720," Revision B, dated December 11, 1990, at the earlier of the following times: \n\n\t\t1.\tPrior to reaching the incorporation thresholds listed in the Boeing Document or within the next 4 years after the effective date of this AD, whichever occurs later; or \n\n\t\t2.\tPrior to reaching the incorporation thresholds specified as calendar dates in the Boeing Document. \n\n\tNOTE: The modifications required by this paragraph do not terminate the inspection requirements of any other AD unless that AD specifies that any such modification constitutes terminating action for 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 (ACO), FAA, Northwest Mountain Region. \n\n\tNOTE: The request should be submitted directly to the Manager, Seattle ACO, and a copy sent to the cognizant FAA Principal Inspector (PI). The PI will then forward comments or concurrence to the Seattle ACO. \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 No. D6-54996, "Aging Airplane Service Bulletin Structural Modification Program - Model 707/720," Revision B, dated December 11, 1990, which incorporates the following list of effective pages: \n\nTABLE OF EFFECTIVE PAGES\n\nPage Number\nRevision Number\nDate\n Page a \t\t\nRevision B \nDecember 11, 1990\nPage b \t\t\nInitial Release\nNovember 7, 1989\nPages c.1-d.5 \n Revision B \t\nDecember 11, 1990\nPage e \nRevision A\t\nSeptember 14, 1990 \nPages f-1.0.1 \nInitial Release\nNovember 7, 1989\nPage 1.0.2 \nRevision B \nDecember 11, 1990\nPages 1.0.3-2.0.2 \nInitial Release\nNovember 7, 1989\nPages 3.0.1-3.1.8 \nRevision B\nDecember 11, 1990\nPage 3.1.9\nInitial Release \nNovember 7, 1989\nPages 3.1.10-3.4.1 \t\nRevision B\nDecember 11, 1990\nPages 3.4.2-3.6.1 \nInitial Release \nNovember 7, 1989\nPages 4.0.1-5.1.5 \t\nRevision A\nSeptember 14, 1990\nPages 5.1.6-5.1.8 \t\nRevision B\nDecember 11, 1990\nPages 5.1.9-5.1.11 \t\nRevision A \nSeptember 14, 1990 \n\n\tBoeing Document No. DC-54996, "Aging Airplane Service Bulletin Structural Modification Program - Model 707/720," was issued by The Boeing Company on November 7, 1989. The Boeing Company has made two revisions to the November 7, 1989, document: "Revision A" was issued on September 14, 1990, and "Revision B" was issued on December 11, 1990. The preceding Table of Effective Pages depicts the original and revised pages that have received incorporation by reference approval. \n\n\tThis 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 Airplane Group, P.O. Box 3707, Seattle, Washington 98124. Copies may be inspected at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 1601 Lind Avenue S.W., Renton, Washington; or at the Office of the Federal Register, 1100 L Street S.W., Room 8401, Washington, D.C. \n\n\tThis amendment (39-6926, AD 91-07-19) becomes effective on April 29, 1991.