90-18-04 BOEING: Amendment 39-6714. Docket No. 89-NM-211-AD. \n\n\tApplicability: All Model 767-200 and -300 series airplanes on which Production Revision Record (PRR) B-11777 has not been incorporated, certificated in any category. \n\n\tCompliance: Required within 18 months after the effective date of this AD, unless previously accomplished. \n\n\tTo prevent loss of stabilizer trim and decreased pitch control authority, accomplish the following: \n\n\tA.\tFor airplanes identified in Boeing Alert Service Bulletin 767-29A0039, dated May 11, 1989: Install the hydraulic power transfer unit system with its associated components in accordance with the procedures outlined in that service bulletin, or Revision 1, dated November 2, 1989. \n\n\tB.\tFor all other airplanes: Install a hydraulic power transfer unit system with its associated components in accordance with the procedures approved by the Manager, Seattle Aircraft Certification Office, FAA, Transport Airplane Directorate; or in accordance with Boeing Alert Service Bulletin 767-29A0039, Revision 1, dated November 2, 1989. \n\n\tC.\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\tD.\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\tAll persons affected by this directive who have not already received the appropriate service documents from the manufacturer may obtain copies upon request to Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124. These documents may be examined at theFAA, Northwest Mountain Region, Transport Airplane Directorate, 1601 Lind Avenue SW, 5th Floor, Renton, Washington, or Seattle Aircraft Certification Office, 1601 Lind Avenue SW, 2nd Floor, Renton, Washington. \n\n\tThis amendment (39-6714, AD 90-18-04) becomes effective on October 9, 1990.