94-01-02 BOEING: Amendment 39-8784. Docket 93-NM-127-AD. \n\n\tApplicability: Model 767 series airplanes; as listed in Boeing Service Bulletin 767-29- 0021, Revision 4, dated May 12, 1988; certificated in any category. \n\n\tCompliance: Required as indicated, unless accomplished previously. \n\n\tTo prevent the inability to maintain hydraulic system power in the event that power is lost in both engines, accomplish the following: \n\n\t(a)\tWithin 4,000 hours time-in-service or 15 months after the effective date of this AD, whichever occurs later, replace the ram air turbine (RAT) airspeed switch; cap and stow the wire between the RAT airspeed switch and the air/ground relay; and perform a functional test of the RAT deployment system; in accordance with Boeing Service Bulletin 767-29-0021, Revision 4, dated May 12, 1988.\n \n\t(b)\tAn alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager,Seattle Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Seattle ACO. \n\n\tNOTE: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO. \n\n\t(c)\tSpecial flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate the airplane to a location where the requirements of this AD can be accomplished. \n\n\t(d)\tThe modification shall be done in accordance with Boeing Service Bulletin 767-29-0021, Revision 4, dated May 12, 1988, which contains the following list of effective pages: \n\n\n\nPage Number\nRevision Level\nShown on Page\t\nDate \nShown on Page \n1-4, 6, 10\n4\nMay 12, 1988 \n5, 7-9, 11-14\n1\nAugust 10, 1984 \n\nThis 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 98124-2207. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. \n\n\t(e)\tThis amendment becomes effective on February 14, 1994.