83-24-03 BOEING: Amendment 39-4774. Applies to Model 707 and 720 series aircraft certificated in all categories. Accomplish the following within 120 days after the effective date of this AD, unless already accomplished within the last 21 months, and at intervals thereafter not to exceed 24 months: \n\n\tA.\tVisually inspect the lower rudder tab control rod assemblies, including all dash numbers, which have been in service more than 5 years, in accordance with Boeing Service Bulletin 3424, dated July 1, 1983, or later FAA approved revisions. \n\n\tB.\tReplace any rod assembly exhibiting cracks or corrosion with a new or reconditioned rod assembly.\n \n\tC.\tAlternate means of compliance which provide an equivalent level of safety may be used when approved by the Manager, Seattle Aircraft Certification Office, FAA, Northwest Mountain Region. \n\n\tD.\tAircraft may be ferried to a base for maintenance in accordance with Section 21.197 and 21.199 of the Federal Aviation Regulations. \n\n\tE.Upon request of the operator, an FAA Maintenance Inspector, subject to prior approval of the Manager, Seattle Aircraft Certification Office, FAA, Northwest Mountain Region, may adjust the repetitive inspection intervals specified in this AD to permit compliance at an established inspection period of an operator, if the request contains substantiating data to justify the adjustment period. \n\n\tAll 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 the FAA, Northwest Mountain Region, 9010 East Marginal Way South, Seattle, Washington. \n\n\tThis amendment becomes effective January 3, 1984.