90-25-07 BOEING: Amendment 39-6788. Docket No. 89-NM-269-AD. \n\n\tApplicability: All Model 707/720 series airplanes, certificated in any category. \n\n\tCompliance: Required as indicated, unless previously accomplished. \n\n\tNOTE: This AD references Boeing Document Number D6-54928, "Aging Airplane Corrosion Prevention and Control Program, Model 707/720," Revision A, dated July 28, 1989, for inspection procedures, compliance times, and reporting requirements. In addition, this AD specifies inspection and reporting requirements beyond those included in the Document. Where there are differences between the AD and the Document, the AD prevails. \n\n\tTo control corrosion, accomplish the following: \n\n\tA.\tWithin one year after the effective date of this AD, revise the FAA-approved maintenance program to include the corrosion control program specified in Boeing Document Number D6-54928, "Aging Airplane Corrosion Prevention and Control Program, Model 707/720," Revision A, dated July28, 1989, (hereinafter referred to as "the Document"). \n\n\tNOTE: All structure found corroded or cracked as a result of an inspection conducted in accordance with this paragraph must be addressed in accordance with FAR Part 43. \n\n\tNOTE: Where non-destructive inspection (NDI) methods are employed, in accordance with Section 4.1 of the Document, the standards and procedures used must be acceptable to the Administrator in accordance with FAR 43.13. \n\n\tNOTE: Procedures identified in the Document as "optional" are not required to be accomplished by this AD. \n\n\tB.\t1.\tIf, as a result of any inspection conducted in accordance with the program required by paragraph A., above, Level 3 corrosion is determined to exist in any area, accomplish one of the following within 7 days after such determination: \n\n\t\ta.\tSubmit a report of any findings of Level 3 corrosion to the Manager of the Seattle Aircraft Certification Office (ACO) and inspect the affected area on all Model 707/720 aircraftin the operator's fleet; or \n\n\t\tb.\tSubmit for approval to the Manager of the Seattle ACO one of the following: \n\n\t\t\t(1)\tProposed adjustments to the schedule for performing the tasks in that area on remaining airplanes in the operator's fleet, which are adequate to ensure that any other Level 3 corrosion is detected in a timely manner, along with substantiating data for those adjustments; or\n\n\t\t\t(2)\tData substantiating that the Level 3 corrosion found is an isolated occurrence and that no such adjustments are necessary. \n\n\tNOTE: Notwithstanding the provision of Section 1.1. of the Document that would permit corrosion that otherwise meets the definition of Level 3 corrosion (i.e., which is determined to be a potentially urgent airworthiness concern requiring expeditious action) to be treated as Level 1 if the operator finds that it "can be attributed to an event not typical of the operator's usage of other airplanes in the same fleet," this paragraph requires that data substantiating any such finding be submitted to the FAA for approval. \n\n\tNOTE: As used throughout this AD, where documents are to be submitted to the Manager of the Seattle ACO, the document 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. The Seattle ACO will not respond to the operator without the PI's comments or concurrence. \n\n\t\t2.\tThe FAA may impose adjustments other than those proposed, upon a finding that such adjustments are necessary to ensure that any other Level 3 corrosion is detected in a timely manner. \n\n\t\t3.\tPrior to the compliance time specified for the first task required in the adjusted schedule approved under paragraph B.1. or B.2. of this AD, revise the FAA-approved maintenance program to include those adjustments. \n\n\tNOTE: The reporting requirements of this paragraph and of paragraph D., below, do not relieve operators fromreporting corrosion as required by FAR Section 121.703. \n\n\tC.\tTo accommodate unanticipated scheduling requirements, it is acceptable for a repeat inspection interval to be increased by up to 10% but not to exceed 6 months. The cognizant FAA Principal Inspector (PI) must be informed, in writing, of any extension. \n\n\tNOTE: Except as provided in this paragraph, notwithstanding Section 3.1., paragraph 4, of the Document, all extensions to any compliance time must be approved by the Manager of the Seattle ACO. \n\n\tD.\tReport forms for Level 2 corrosion and a follow-up report for Level 3 corrosion must be submitted at least quarterly in accordance with Section 5.0 of the Document. \n\n\tE.\tIf the repeat inspection or task intervals of an operator's existing corrosion inspection program are shorter than the corresponding intervals in Section 4.3 of the Document, they may not be increased without specific approval of the Manager of the Seattle ACO. \n\n\tF.\tBefore any airplane that is subject to this AD can be added to an air carrier's operations specifications, a program for the accomplishment of tasks required by this AD must be established in accordance with the following: \n\n\t\t1.\tFor airplanes that have previously been operated under an FAA- approved maintenance program, the initial task on each area to be accomplished by the new operator must be accomplished in accordance with the previous operator's schedule or with the new operator's schedule, whichever would result in the earlier accomplishment date for that task. After each task has been performed once, each subsequent task must be performed in accordance with the new operator's schedule. \n\n\t\t2.\tFor airplanes that have not previously been operated under an FAA- approved maintenance program, each initial task required by this AD must be accomplished either prior to the airplane's being added to the air carrier's operations specifications, or in accordance with a schedule approved by the Manager, Seattle ACO.G.\tIf corrosion is found to exceed Level 1 on any inspection after the initial inspection, the corrosion control program for the affected area must be reviewed and means implemented to reduce corrosion to Level 1 or better. \n\n\t\t1.\tWithin 60 days after such a finding, if corrective action is necessary to reduce future findings of corrosion to Level 1 or better, such proposed corrective action must be submitted for approval to the Manager, Seattle ACO. \n\n\t\t2.\tWithin 30 days after the corrective action is approved, revise the FAA- approved maintenance program to include the approved corrective action. \n\n\tH.\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, Transport Airplane Directorate. \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\tI.\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 requirements shall be done in accordance with Boeing Document Number D6- 54928, "Aging Airplane Corrosion Prevention and Control Program, Model 707/720," Revision A, dated July 28, 1989. 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 Airplane Group, P.O. Box 3707, Seattle, Washington 98124. Copies may be inspected at the FAA, Transport Airplane Directorate, Northwest Mountain Region, 1601 Lind Avenue S.W., 5th Floor, Renton, Washington; or at the Office of the Federal Register, 1100 L Street N.W., Room 8301, Washington, D.C. \n\n\tThis amendment (39-6788, AD 90-25-07) becomes effective on December 31, 1990.