89-26-12 BOEING: Amendment 39-6429. Docket No. 89-NM-96-AD. \n\tApplicability: Model 757 series airplanes, listed in Boeing Service Letter 757-SL-27-43, dated May 3, 1989, certificated in any category. \n\n\tCompliance: Required within the next 60 days after the effective date of this AD, unless previously accomplished. \n\n\tTo prevent unacceptable airframe vibration during flight, accomplish the following: \n\n\tA.\tConduct a one-time inspection of the left and right elevator power control actuator to determine the presence of the bushings, in accordance with Boeing Service Letter 757-SL-27-43, dated May 3, 1989. If any bushing is missing, prior to further flight, install a new bushing in accordance with the Boeing Model 757 Maintenance Manual. \n\n\tB.\tWithin 10 days after the completion of the inspection required by paragraph A., above, submit a report of findings, positive or negative, to the Manager, Manufacturing Inspection District Office, FAA, 7300 Perimeter Road South, Seattle, Washington 98108. Reports must include the aircraft serial number. \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, FAA, Northwest Mountain Region. \n\n\t\tNOTE: The request should be forwarded through an FAA Principal Maintenance Inspector (PMI), who will either concur or comment, and then send it to the Manager, Seattle Aircraft Certification Office. \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 the FAA, Northwest Mountain Region, Transport Airplane Directorate, 17900 Pacific Highway South, Seattle, Washington, or Seattle Aircraft Certification Office, 9010 East Marginal Way South, Seattle, Washington. \n\n\tThis amendment (39-6429, AD 89-26-12) becomes effective on January 26, 1990.