90-01-09 BOEING: Amendment 39-6463. Docket No. 89-NM-76-AD. \n\tApplicability: All Model 767 series airplanes, certificated in any category, equipped with Allied Signal 8th stage bleed system check valve, part number 3202164-2 or -4. \n\n\tCompliance: Required as indicated, unless previously accomplished. \n\n\tTo prevent engine shutdown or damage, and/or pneumatic system damage, accomplish the following: \n\n\tA. Within the next 250 hours time-in-service after the effective date of this AD, or prior to accumulating 600 hours total time-in-service on the valve, whichever occurs later, perform the inspections of the check valve in accordance with Boeing Alert Service Bulletin 767-36A0030, dated April 27, 1989. Prior to further flight, repair or replace check valves which do not pass all required inspections. \n\n\tB. Used check valves must be inspected and repaired, if necessary, in accordance with Boeing Alert Service Bulletin 767-36A0030 dated April 27, 1989, prior to installation in any Model 767 series airplane. \n\n\tC. Installation of a P/N 320544-1 valve in lieu of a P/N 3202164-2 or -4 valve constitutes terminating action for the inspection required by this AD. \n\n\tD. An 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. NOTE: 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\tE. Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base for the accomplishment of the inspections required by this AD. All persons affected by this directive who have not already received copies of the appropriate service bulletins cited herein 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 the Seattle Aircraft Certification Office, 9010 East Marginal Way South, Seattle, Washington. \n\n\tThis amendment (39-6463, AD 90-01-09) becomes effective on February 12, 1990.